How to Build a Simple MX5 Chain Drive Differential - No Machining, No Welding

[@lesanddeansarverandrevras1171]

There's only a small group of people that are interested in this kind of fabricating. thank you for all you do and thinking outside the box 🤜🤛👍 after struggling to find something Worthy on KZbin you bring a ray of Hope that there's other like-minded people like myself

[@bikeroftheeverywheres864]

Weeks and months of searching led me to this video, thank you Sir for laying everything out in an easy to understand way!

[@DougsShed]

Glad it helped!

[@Biokemist-o3k]

@@DougsShed I have to say that I did not know what I was looking for at first but then. I found this video everything clicked. Thank you.

[@beardedbaldguy4359]

You have the best and easiest example on the internet period. Thank you so much for sharing your knowledge and wisdom with us! I’m doing a krosskart build. This will be how I do the rear end.

[@DougsShed]

Happy to help!

[@beanvo9924]

It’s amazing how he just drill things and it worked. It looks easy but man if you did something like this before, you’ll know how hard it is.

[@DougsShed]

I have made a few of these before!

[@alexx09RO]

Wow - the part where you suggested using an oil filter as a casing was just amazing. Never would come to my mind! Nice one!

[@DougsShed]

Glad it helped!

[@yellow3222]

This is Gold !!! Your video has improved humanity.

[@michaelmayo3127]

That what I like to see, no puller, just a crowbar and a club-hammer, always get the job done. Bravo Mr. Yardex!! The sheet metal-man. Great Video.

[@DougsShed]

I go by the old adage "Everything in the toolbox is a hammer!"

[@FrogHairsPond]

If this hasn't blown up yet it will soon! I'll play my part! Awsome vid and thanks

[@AquatechnicLive]

picked up a buggy project recently, and got myself a honda shadow 750 engine, this may be the solution i need for my rear end! thank you!

[@DougsShed]

Sounds like a nice project.

[@frotobaggins7169]

there may not be a welder or a lathe here but there sure is an experienced, skilled hand or two. good video.

[@firstlastname99]

You're an excellent instructor here at the University of KZbin. Thanks for the instruction.

[@DougsShed]

Glad to help

[@EngineeredToDesign]

Absolute genius! I just planned a whole new build AWD vehicle and completely overlooked the fact that I would need at least a front differential otherwise it would be very difficult to drive! Thank you

[@DougsShed]

You might even need a centre differential to avoid axle wind-up between front and rear (if running on paved surfaces).

[@White_Night_Demon]

@@DougsShed so you would need 3 differentials in total? One for front, one for rear and one for the center for a AWD system?

[@DougsShed]

@@White_Night_Demon Have a look at Dennis Palatov's blog on his build of his 4wd sports car prototype www.dpcars.net/dp1dsn/dd.htm

[@DougsShed]

@@White_Night_Demon Have a look at Dennis Palatov's blog on the build of his 4wd prototype www.dpcars.net/dp1dsn/dd.htm Full blog here www.dpcars.net/dp1dsn/

[@White_Night_Demon]

@What's going on in Doug's Shed? thanks will check it out - been meaning to make my own ratrod that has 5 mode steering(Front, rear, all wheel, same direction and off - just for fun haha), 3 mode driving system (front drive, rear drive and all wheel drive, I believe 4WD only lets you choose either FWD or RWD but can't do AWD?), and it'd also have the option to be pedal powered (Which is why the differential is chain driven rather than a propellar shaft)and or driven by a small engine (I was thinking maybe a 2 stroke one cylinder(so I dont have to worry about changing the engine oil every so often since it gets changed when I fuel up altogether), or that yamaha 4 stroke four cylinder engine with crossplane crankshaft motobike engine (since I like its exhaust note hehe), or if I can get someone to build me one, a 2 stroke small engine v8 that is built from 8 separate chainsaw or weed wacker engines haha since no small engine 2 stroke v8 exists which means it'd have to be custom built and tuned and with a crossplane crankshaft too to boot - and that'd sound awesome!). The pedal power will most definitely help when I run out of fuel for the small engine or if it dies for whatever reasons! Hahaha I'll also see if I can use some bike gear sprokets set on the differential and add a derailer so I can fine tune the the speed on the fly like on a bike! The bulk of the torque and speed changes will be on (maybe custom built unless I can find one that fits a small engine that is also not heavy...) 3 speed + reverse gearbox that connects the drive from the pedals or the small engine that sits at the front of the ratrod. I was thinking of using plastic PVC tubing for basically the whole body and frame, those tubes you use for plumbing for light weight (And have a higher power to weight ratio when using the small engine...) but I dunno if that'll hold up, especially when I go offroading onto rocks (well small rocks obviously, I doubt I'd be able to climb big ones...hahaha) or speed bumps or whatever that isn't smooth... i have seen a few builds here on youtube where they made go karts out of them PVC piping so it must hold up, right? Hahaha But yeah, that's my plan. WIll first need to design working prototypes for each part of the vehicle before I make the real thing to actual scale for use on the ratrod.

[@benjamindavidson632]

Makes sense. I had a similar idea for an off road buggy I wanted to build. I was going to use a whole rear subframe to keep it as cheap as possible. What I planned to do was weld the miata diff and install a chain ring instead of the ring gear and cut windows in the case to allow the chain to pass through.

[@DougsShed]

It may be difficult to get a large enough diameter sprocket to fit in with the windowed Miata differential case. You could still use the complete subframe etc and mount the simple MX5 chain drive unit to the subframe.

[@alexbuckley1748]

Absolutely brilliant, the best diy fabrication video I've seen in a long time.

[@DougsShed]

Glad you liked it!

[@icouldntthinkofagoodname7216]

Now I have to change the design for my crosskart. Good thing I haven't started buying parts yet lol.

[@larrylamb3480]

And to think that dealers are selling motorcycle differentials for trikes for THOUSANDS OF DOLLARS !!!!! Thank you sir !!!!

[@livinlikelarry8782]

Eyyy brother from another mother larrylivinlife

[@White_Night_Demon]

well first you need to go find a working diff for free for all this to work....

[@RDAUGIRD]

I am building a Harley Davidson Shovelhead powered trike, this will save me a bundle. The only thing I need to add would be inboard brake rotors on the stub axles. The trike is an old-school chopper that will have no fenders and I don't want modern rotors visible at the wheels.

[@bokicar1]

Omg, this is fantastic! I didn't finished the video and I already ordered second hand mazda diff. Thank you very much!

[@DougsShed]

Glad I could help!

[@lesanddeansarverandrevras1171]

Closest I've found to what I was looking for I aquired a go-kart frame for a trade, mid size.. not your little kids kart 😁 Then I was given a V Star 650 shaft drive motor w/ transmission Trying to find a way to either change to chain drive or come up with a short version shaft drive rear end for kart Keep up the good work, and thanks for thinking outside the box.. Apparently I'm not the only one..😂

[@AquatechnicLive]

are you not able to change the shaft coming off the bike engine for a CV to a rear diff from something like a UTV/ATV?

[@chrisbilton]

Hi there I’m so gutted you retired in April I’ve just done a slight bit of research on you , this video is quality !! I’m not to steady handed etc and would much prefer to pay someone to make one for me with the housing like on westgarahes site , if you could point me in a direction to buy one built I would me appreciate it or even the one out the video 🤣 thank you Doug inspires me so much

[@aliterogasolini6401]

Great, thanks for sharing. The art of tinkering in your shed is still alive and well. Will subscribe now.

[@DougsShed]

Thanks 👍

[@yvfcfire58]

How hot does it get while running? I would assume it says fairly cool as there is no ring and pinion. I am considering 3d printing the cover......

[@DougsShed]

Yes, it does not get too hot as there are no hypoid gears constantly revolving. I did make a 3D printed oil/grease retaining cover for one differential. I painted it inside and out to make sure that it was oil resistant.

[@RoadWarrior427]

Ingenious!!! I really appreciated this vid. I would have never thought of this on my own. Thanks for sharing!

[@ptyatas4380]

I definitely could have used this 2 years ago before I mad a straight axel go-kart rear end for my miata kart powered by a gsxr1000 motor, definitely genius work my sir

[@ToxicSocietyTroll]

I don't need one, but sure enjoyed you teaching me how to build one if I do! Thanks for sharing your knowledge!

[@DougsShed]

Thanks for watching!

[@ecobogan238]

Very cool mate, am looking to do this on an off road buggy. Great to use existing, much cheaper and well designed components that are in the millions lying idle worldwide. Keep it up

[@martingardener90]

Very similar to one I built a while back for a trike using Sierra diff parts. I had to get some machining done but nothing too expensive. I initially was going to mount a disc on the end of the can for parking brake but changed it to using the can as a band brake, now wish I'd stuck with the disc set up. Also was going to mount two sprockets - one for electric driven reverse but things were getting too complicated!

[@DougsShed]

Yes they can get complicated. I have built versions with single discs, twin discs and various types of electric reverse.

[@FilterYT]

Very generous of you, thank you!

[@BigKandRtv]

Excellent tutorial! I may be able to do this myself. Thanks for sharing.

[@DougsShed]

You can do it!

[@tonyd7164]

FANTASTIC ! thanks for doing all the R&D. cheers

[@JA-dk3xc]

2 SAY THAT THIS IS GENIOUS... ITS AN UNDER STATEMENT 4 SURE.. THANKU 4 ALL UR EFFERTS .. 2 CREATE .. SUCH A WELL THOUGHT OUT VID.. EVEN I GOT IT..

[@DougsShed]

Thank you for your kind comments.

[@kennyguillotte1881]

Looks great! Do you have a parts list.

[@DougsShed]

Click on the "Show More" tab on the video description and you will see details of the bearings and sprocket part numbers and dimensions for the 1.6 and 1.8 NA,NB Mazda differentials.

[@kennyguillotte1881]

@@DougsShed thank you.

[@Biokemist-o3k]

Beautiful!!!! I am going to start building one of these for a mini dump truck for homeowners and construction teams. Thank you for the idea.

[@DougsShed]

Sounds like a great idea.

[@Biokemist-o3k]

@@DougsShed I just located two Rebel 500 motors that I am going to use for the mini dump truck. They are chain drive so I am still going to have to build one or two of these. I am thinking about building a 1/2 to 3/4 size dump truck to use around the farm and put it up for sale but I believe that it will sell so fast it will make my head spin. At least that is what people tell me who hear me discuss the build. I found the coolest thing on marketplace. It is a Drill press and tapping press station that is from an old machine shop that closed sometime after the Second World War and stayed locked and sealed. I was privy to the family opening it and I made them an offer and they accepted it. I am going to try and start my KZbin channel with a short video about it. U will send you a link when I make th video. Thanks brother.

[@Yosser70]

absolutely fantastic work mate 👍🏻

[@DougsShed]

Thank you!

[@Yosser70]

Hi mate. I’m wanting to use this in an upcoming build. I want it more for strength rather than a working diff, because it’s going on a drag kart. Would a welded diff work the same way?

[@MikeJones-js8gh]

Great. Video . Thanks. One question. Where can you mount a brake disk. Thanks again

[@DougsShed]

With a chain drive differential, you can mount disc rotors on both of the flanged output shafts (sandwiched between the flange and the bolt-on CV joint). On LSDs and 'spool' units you can fit a single disc rotor on the body of the diff housing but this needs an additional machined mount/spacer for the disc.

[@magnon1975]

Thanks for sharing your ideas ! So useful to fellow builders.

[@DougsShed]

Thanks - That's why I posted the video....

[@derkaderka808ify]

Get out of here!!! That was amazing!! Very well described !! Thankyou kind sir for sharing your knowledge!!! Thankyou

[@DougsShed]

You are very welcome!

[@jamesandonian7829]

Amazing idea!!!! Literally, overkill for any go kart! I love it

[@Dave5843-d9m]

Sidecar outfits don’t turn well in any gear. ;)

[@lesanddeansarverandrevras1171]

No guts no glory.. Trying to put a shaft drive V Star 650 in mid size go-kart chain drive kart rear end/shaft drive street bike motor and transmission.. lol I have the need for speed 😂

[@RDAUGIRD]

How wide is this unit, flange to flange? I want to build one for a Harley Davidson Shovelhead powered trike.

[@DougsShed]

1.6 diff is 240mm and 1.8 diff is 278mm

[@bruceperron3796]

If a person welds,a flange could be welded to the bottom of the tube and then bolted down with the sprocket bolts?

[@DougsShed]

Could be done however you would have problems changing the sprocket

[@mouseinthefalls7836]

Totally awesome.... Now I can go make my own for an electric 4x4 go cart. Thank you sir for your time and information on this.

[@DougsShed]

Go for it!

[@mouseinthefalls7836]

@@DougsShed , As I build my project I will be posting videos of it, until then I will do my research on parts and if you like you are very welcome to check out the few videos that I have and offer your suggestions if you wish.

[@petecort5446]

Amazing work, I'll be transferring some of your tips to my self build lsd diff, I turned a 10mm plate and threaded to allow attachment of the cup(welded) one side and the sprocket the other 👍

[@RUSTICW0LF]

That was great mate, thanks for sharing. Off to the scrappy now. 👍🐺👍

[@DougsShed]

Glad you enjoyed it

[@2000freefuel]

Awesome, now show us how to make a differential for the bottom bracket crank set!

[@chrislachance6304]

I really live what you’ve done here. Great idea and completely useful. I am looking to build a buggy for my daughter to cruise around my lake property and I’d like to make a 4WD for her and this is perfect but I need two haha. Could you tell me where you sourced the bearings. I’m living in Ecuador so I will likely need to source parts in the US.

[@DougsShed]

Have a look on ebay.com for US suppliers Found this one SBPF207-35 35mm housed bearings ebay item 282068285209 40mm version for the larger MX5 units should also be available with the pressed steel flanges SBPF208-40, or failing that the cast iron flanged housed bearings or pillow block type are usually available.

[@glen_nz]

Really appreciate you sharing this. Been wanting to do a DIY one of these for a while and this will help me a lot!

[@DougsShed]

Glad it was helpful!

[@RDAUGIRD]

I considered a jackshaft, but it will be easier to just machine a spacer and put the sprocket in line with the trans sprocket. Thanks again for the great video and information.

[@gustavovillalobos9657]

What's the part number of the bearings. And thank you for the tip

[@DougsShed]

Bearing part numbers are in the description below the video.

[@dexterstiff7160]

Very good video but how do you mount the diff

[@DougsShed]

Usually bolted to a pair of sliding or pivoting plates to allow chain tensioning. Have a look at some of my other videos to see typical installations.

[@letstalk9037]

Very useful information and well made video. Can you show us how to make one for an electric scooter?

[@RDAUGIRD]

I wonder if there are any off the shelf brake rotors that will fit the 1.8 stub axles?

[@DougsShed]

Hi Richard, Suzuki GSX600f (89-97) rear disc rotors should be easy to adapt to suit the 1.8L. You would need to redrill to 110mm pcd. Rotors are 250mm diameter. These ones look like they have enough metal to redrill at 45 degrees to the original mounting holes www.ebay.co.uk/itm/203832938196 The above rotors should fit the 1.6L NA/NB (100mm pcd) output flanges using the existing bolt holes in the rotors)

[@larrysullivan6536]

I absolutely brilliant I’d like to no the best way to mount that into a trike frame though if possible ?? Cheers great video larrysullivan in London

[@DougsShed]

Have a look at www.casarva.co.uk. They manufacture mounting frame and suspension kits.

[@manxman8008]

I have skills but no lathe - no room - in a flat - so manmy thanks f0or sharing

[@DougsShed]

You are welcome. Have a Happy New Year.

[@jhonatanzegarra2670]

I would like to know if this differential would be suitable for a 150 - 200 cc engine. that move from 1 to 4 people, or it would be too heavy that it would lose energy. excellent video, a very clean job, greetings from Peru! answer please!

[@DougsShed]

The smaller differential from the Mazda Miata 1.6 may be better for your small car. Many other small car differentials can be converted to chain drive in a similar way if Miata differentials are not available in Peru.

[@chuckvoss9344]

thank you, for sharing this detailed information with us.

[@DougsShed]

You are welcome!

[@WilliamGuess-ns6th]

How are you supporting the axles outside, and are you just relying on the clips to hold the axles in?

[@DougsShed]

The clips hold in the output shafts (usually need extreme violence to get them back off). The CV type axles do not put any great axial loads on the output shafts.

[@ethanwelch6345]

What kind of bearings and output shafts did you get? Or where? Really great video you even explained how much grease to use - thanks for making this

[@DougsShed]

I have used housed, self aligning bearings which combine the bearings with circular flanged, pressed steel housings SBPF207 for differentials with 35mm bearing spigots or SBPF208 for differentials with 40mm bearing spigots. The output flanged, stub shafts come with the MX5 differentials. The ones on the 1.6L MX5 have (4)10mm bolts on a 100mm pcd for MX5 bolt-on CV joints. The ones on the 1.8L MX5 have (4) 10mm bolts on a 110mm pcd for bolt-on MX5 CV joints.

[@bigsquatchsasfoot1964]

This is genius and well thought out my good man and actually exactly what I was looking for ( being to thick to think of something this clever myself) thanks so much for sharing appreciate it very much 👍

[@DougsShed]

You're welcome!

[@Essiee261]

So filling the diff up with grease acts like a limited slip? Or does it actually need to move and lubricate inside? Most greased bearings should have a lot lease than you'd expect, 10-20% fill to allow it to move around the bearings, when a bearing is packed full of grease it quickly overheats and destroys itself. Great job and great video, thanks for sharing!

[@DougsShed]

No - Grease filling will not create an LSD. We use LSD versions of the MX5 differentials, either the stock viscous coupled LSD, the Torsen Type 1 or type 2 or an aftermarket ATB LSD. The bearings are sealed and do not see the grease which fills the differential case. There are still some voids in the differential case which can allow for expansion. Heat build-up in the case is not as great as with a conventional differential as there are no crown-wheel and pinion gears (which are the primary cause of heat).

[@lesafighter]

you sir are a genius :D

[@ilovebuhbbles2308]

Im so glad I came across this because Im gonna build a crosskart this summer and having no diff kinda sucks

[@DougsShed]

You may wish to use an limited-slip type differential if you are using your crosskart on dirt/sand/mud. Probably best to look for a plate and ramp type rather than a Torsen or ATB.

[@SEILLC]

I need one of these, probably the 1.6 version. Perfect size for my project. I'd first like to see the bolts in use though.

[@bodge7255]

Hi Doug. First of all I doff my hat to you. This is awesome. I'm mechanically minded myself i love this. Am i right in saying this could be made with pretty much any diff front or rear ?

[@DougsShed]

Yes, I have used many different differentials from cars such as the Ford Sierra (rear diff), Ford Fiesta/Escort/Focus (front diffs), VW Golf (front diff) and BMW (rear diff).

[@RDAUGIRD]

My 1.8 diff and stub axles came yesterday, excited to get started on this project. Do you know of any brake rotors that will fit the output shafts? I believe they are 4x110MM.

[@DougsShed]

Hi Richard, I think I repied to this question a couple of weeks ago. Anyhow - try these Suzuki GSX600f (89-97) rear disc rotors should be easy to adapt to suit the 1.8L. You would need to redrill to 110mm pcd. Rotors are 250mm diameter. These ones look like they have enough metal to redrill at 45 degrees to the original mounting holes www.ebay.co.uk/itm/203832938196

[@polski7267]

Following this for a 1.8 diff now, Where do you get your alloy tube from usually? I’m struggling to find something that’s 108mm Guide is spot on though glad I found your channel I’ve watched a few now

[@DougsShed]

4.1/2" x 10swg (114.3 x3.2mm) www.ebay.co.uk/itm/ALUMINIUM-ROUND-TUBE-3-3-1-4-3-1-2-4-4-1-2-5-6-inch-select-size-length/192449775545?var=492464022926&hash=item2ccee687b9:g:3gUAAOSw0F9bm81a

[@joell439]

Wow - thanks for all the details. Just found your channel and this first video I’ve seen immediately deserved a subscription. Looking forward to seeing the rest of your content. 👍👍😎👍👍

[@DougsShed]

Glad it was helpful!

[@zezoner]

Thank you for sharing this. I love your precision and your detail. Cheers

[@DougsShed]

Thank you for your kind words.

[@boltonky]

Appreciate the video one of the best ones on how to do it, if only mx5 stuff wasn't so expensive where i live. Agreed custom work cost as its all about the time it takes

[@DougsShed]

Lots of other differentials which can be converted in similar ways. Just about every small front wheel drive car has a differential which can be converted.

[@tomtilly5887]

Torsen LSD's that are in 1.8 diffs will act like opens unless under load fyi

[@DougsShed]

Indeed! - Torsens and ATBs are not really suitable in off-road vehicles which encounter sand/mud or for vehicles which lift a driving wheel. In those cases a plate and ramp type LSD would be better suited.

[@lonestarsherp7560]

Great video, very easy to do now I have to come up with a project to put that in.

[@DougsShed]

You should!

[@SWINGERINTO]

Thank you, very informative! Is there any reason that this would work differently with a limited slip diff?

[@DougsShed]

I have made many chain drive differentials using lots of different types of limited-slip differentials. The Mazda MX5 Mk1 VLSD (Viscous Coupled LSD) is one of the easiest to convert. The MX5 Torsen type1 and type2 LSDs can also be converted however the housings have quite a few holes to seal up which can be tricky. The MX5 Blackline ATB LSD (as sold by Rally Design) is an excellent base for building a chain drive LSD.

[@SWINGERINTO]

@@DougsShed Thank you! I'm at the parts collection phase, and just recently acquired a 99 miata diff. Great video!!!

[@flyguyeddy]

So where do those stub shafts come from? The 1.6 miata ones are pretty obvious, but afaik the us miata/mx5 has no bolt together stub shaft.

[@DougsShed]

Pretty sure 1.8 Miata with Torsen LSDs were sold in the US. ebay item no. 15008985599 is the torsen type bolt-on output

[@flyguyeddy]

Im referring to the flanged shafts that go in place of the inner tripot that the cv shaft bolts into

[@DougsShed]

@@flyguyeddy CV axles with the 110mm (4) bolt pcd flanges should be available from the 1.8 Miata Check out ebay item no. 353223749811

[@11green11]

Amazing enginuity ! Thanks for sharing such a priceless and useful hack 💪😎👍

[@DougsShed]

My pleasure!

[@nordicweiss]

This is a naive question but how to the stub axles stay in the differential?

[@DougsShed]

The splined part of the stub axles have a radial groove for a wire spring clip. When the stub axle is inserted into the differential the clip is compressed by the mating splines until it reaches the sun gears where the clip expands to lock in behind the gears. To extract the stub axle, the stub axle usually needs levered out or struck a blow to make the clip compress back into the groove.

[@nordicweiss]

thank you, and you're videos are a great resource @@DougsShed

[@Hermanimace]

Hi, I really appreciate you sharing this information with us. I would like to ask what differential he would recommend for a kartcross buggy. It has 10´´ wheels and the working angle is small, but I drive with it on the road and gravel. Now I have no differential there. If you look at my videos, you will understand what I need it for. It is very understeer in sharp corners, but sometimes I need to drift. Thank you very much. (Sorry for my english, I am form Czechia :) )

[@DougsShed]

The Mk1 MX5 (NA) Viscous Coupled LSD (VLSD) would be a good choice. It is small, lightweight and the viscous coupled lsd action gives a compromise of good traction and differential action on corners. Plate and ramp type LSDs give the best traction but can promote understeer (similar to a solid rear axle). Automatic Torque Biassing (ATB) differentials can loose traction on slippery surfaces/gravel/mud or if one drive wheel is off the ground.

[@Hermanimace]

​@@DougsShed OK, thank you very much :)

[@BEYTEK]

good to see another scottish youtube channel

[@DougsShed]

Thanks!

[@bjwest6618]

Always enjoy your videos and your willingness to share knowledge. Most appreciated.

[@DougsShed]

Glad to help

[@danielkarrington8983]

You make it look so easy

[@blackpit3147]

Very well! Cool idea! I really like it! I love these designs, especially home built ones! Big like! Definitely a Subscription!

[@DougsShed]

Thank you! Cheers!

[@PaulA-ky6bv]

How about for a shaft drive? Similar?? I'm building a trike from a Honda Shadow 1100.

[@DougsShed]

No, you just use a conventional rear drive car differential.

[@PaulA-ky6bv]

@@DougsShed the hard part would be finding one small enough. Or incorporating the shaft drive differential into a rear axle assembly

[@DougsShed]

@@PaulA-ky6bv Do you want a live rear axle or an independent rear suspension set up? The Mazda MX5 (Miata) 1.6L is quite small and ideal for an independent set-up. Live axle, perhaps use a Honda Acty pick-up/van type axle.

[@coolhandluke1503]

Dear sir, in your humble opinion would an open center diff like this be impractical in a off road buggy/crosskart with a zx9r motor?

[@DougsShed]

Don't fit a differential to a crosskart - regulations usually do not allow differentials and they will detract from the performance & handling of the vehicle.

[@coolhandluke1503]

@@DougsShed I'm building a piranha from edge performance and the plans I have don't meet race spec, so I wont compete in this one. Not to worried about power loss as the zx9r is a bit overkill, was looking for a 600, but this is what came up in my local area. When you say detract from handling is that because of the single wheel spin making life hard on every type of lose surface? The idea behind the diff was to negate every buggy I've driven Achilles heel, poor turning circle, my plan was to create a cheaper open diff and if all goes well, then I replace it with a helical gear LSD, not even sure if this is viable, I would have to be sure the lsd would even work with the weight and power of buggy. Any advice is appreciated and thank for taking the time to respond

[@DougsShed]

@@coolhandluke1503 If you are set on using a differential, a viscous coupled type LSD would probably be the best as it gives good slow speed turning as well as reasonable grip on loose surfaces. I would not use a helical geared ATB as these can have very poor traction on slippy surfaces or when a wheel is off the ground. A plate and ramp LSD would give best traction but these can also induce understeer and larger turning circles at low speed (they are also high maintenance). I have used the Mazda MX5 viscous LSDs in many of my chain drive units

[@mikesedutto2213]

Just some questions purely out of curiosity. What about gear oil shouldn't the diff be submerged in it? What about the heat build-up and pressure build up inside of the case? Could you do anything to vent the pressure because unlike a normal differential the case on this moves whereas a standard diff uses a pinion gear and the case is stationary.

[@mikesedutto2213]

otherwise really interesting and it gives me plenty of ideas. thanks!!

[@DougsShed]

Hi Mike, Differentials with crown-wheel and pinion gears put a bit of heat into the gear oil. The chain drive differential does not use these constantly running gears therefore there is less heat build-up. The chain drive units have a bit of air-space for expansion and the unit does not have a perfect seal. We run them on grease to minimise any loss of lubricant.

[@mikesedutto2213]

@@DougsShed alright makes sense, I could definitely see the pinion and main ring gear generating the most heat but I would certainly pack that puppy full of grease as best I can haha thanks for the response

[@MindField_Custom]

Doug, Absolutely amazing ingenuity. I do have a question. How much difference is there between the width of the original LSD and your chain driven LSD? Does the track width change much, or at all? I’m working on a design for a trike and I’m hoping to use something like this setup.

[@DougsShed]

The width between the output flanges of the differential is the same as the original Miata/MX5/Eunos. However, the position of chain sprocket may require the differential to be offset from the car's centre line, which would require different length drive shafts. If the bike engine can be offset or a jack-shaft can be used, you could fit the differential such that equal length (stock) drive shafts can be used.

[@shannongeisler6755]

Curious what it would cost to have you make one and send it to new jersey?

[@DougsShed]

You can build one yourself with basic tools for less than the postage cost from here!

[@shannongeisler6755]

@@DougsShed yeah i actually found a guy that has several mx5 miatas he is parting out and doing some trading with him for the whole rear subframe of some of them. Im in the process of making my first cross kart and dont want a solid rear axle. What are your suggestions for mounting your design? I am doing an independent rear suspension. Just trying to gather all of the parts im using before i start the build. Thanks again for sharing this awesome set up!!

[@SCRUB50187]

I have watched this video many times and now i want to build one but I am having a hard time trying to find a sprocket that will fit on either one. Has anyone found anything that will bolt on to either one? I am not concerned about sealing it. I am mainly concerned about finding something that lines up with the bolt holes. It can even be a 5 bolt pattern for the bigger one or a 4 bolt pattern for the smaller one or does someone know of a different differential tgat you could easily get a sprocket for?Thanks for all of the help.

[@DougsShed]

There may be an existing bike sprocket which could be modified to suit the differentials. Probably have to drill alternative holes in the sprocket and possibly open up the centre hole. Companies such as Talon can custom machine sprockets to suit. Alternatively, blank sprockets are available on eBay and you would need to get the centre hole and fixing holes drilled.

[@anthonybrown7959]

Thats awesome. How cheap. I know of folk paying 1200 for a full works diff. I know which way I will be going. Could you list the bearings/ caps and suppliers please. Looking forward to seeing what you post next.

[@DougsShed]

The bearing and sprocket details and suppliers are now listed in the video description below the video (click "Show more..) to see all the text.

[@stevewhitesell4195]

Great video! Could you by chance tell me the the width, bearing shoulder to bearing shoulder, on a 1.8 miata diff? I'm building a small dune buggy, waiting on parts, antsy to get frame welded up.

[@DougsShed]

On the 1.8 Miata open differential fitted with the self-aligning, side mount bearings, the distance between the outer faces of the bearing mounting flanges is approximately 175mm.

[@stevewhitesell4195]

@@DougsShed Thank you so much. I'm looking at rebuilding a miata Tochigi Fuji Super LSD with broken tabs on the friction cones. Unable to find parts so may be tig welding new tabs on.

[@DougsShed]

That is a common problem with Fuji LSDs. Like you I could not find replacement friction cones for an RX8 Fuji LSD. The diff still worked with the cracked frictions in place (minus one of the broken off tabs).

[@RDAUGIRD]

Oops, one more question. The distance from the sprocket to the axle flange?

[@DougsShed]

Left side of sprocket to outer face of left output shaft is about 103mm (on the 1.8L diff)

[@RDAUGIRD]

@@DougsShed Thanks, I have a diff in the mail I'm ready to start this project.

[@aaronmccarthy130]

Great video, I've found 2 potential diffa for my application. One is an open 1.8L 4:1 and one is A super fuji 3:6. The car will be R1 powered and FWD, so I'm leaning towards the LSD. Will that ratio suit? Will changing sprocket size make up for difference in final drive ratio?

[@lenny0347]

glad i seen this, cheers mate

[@DougsShed]

Thanks, hope it was useful.

[@RDAUGIRD]

One more thought, the diff doesn't care which side the sprocket is on, am I correct? You could mount it "backwards" in the chassis, and the axle will still turn the same direction as the power put to the sprocket. I am trying to center the diff in the chassis, and still have the diff sprocket line up with the transmission sprocket. The body of the trike is a limiting factor keeping me from offsetting the diff one side or the other.

[@DougsShed]

Most differentials can be run in either direction. Open diffs, viscous coupled LSDs and ATBs run OK either way. Plate & Ramp clutched types can only rotate one way. An alternative to the chain line problem is to use a jack-shaft to move the chain to the position of the differential's sprocket. This allows you to use standard length axles from the differential.

[@KurNorock]

maybe I missed it, but how do the output shafts stay secured to the differential? Seems like they would just fly out while in use.

[@DougsShed]

Hi - There are wire snap rings which fit onto the output shafts. These snap rings lock behind the gears inside the differential.

[@KurNorock]

@@DougsShed right.. but how do you get those snap rings on with that aluminum can around everything?

[@DougsShed]

@@KurNorock The clips fit to the output shafts before they are inserted into the differential. Once in place, the clips expand and lock behind the sun gears. To get the shafts back out, you usually need to strike the output shat flanges with a hammer or use a slide hammer. This compresses the spring clips below the level of the splines and enables the shaft to slide out.

[@georgeclarke1183]

would this mazda 1.8 differential based conversion be able to handle the power of honda blackbird 1100 engine

[@DougsShed]

1.8L (up to 2005) differential is pretty strong and should cope with the power from a Blackbird. My choice would be the after-market, Blackline HLF030 torque biassing LSD - This unit is relatively cheap and easy to seal up and is compatible with the 1.8L (up to 2005) model's CV joints or output shafts. Available from Rally Design www.rallydesign.co.uk/product_info.php?cPath=885_2937_2975&products_id=24642

[@shaynegadsden]

It would easily handle it the mazda 1.8 has double the torque of a blackbird

[@Accumulator1]

You built it? Where is the scene where you built those spider gears.

[@DougsShed]

The base differential case and gears are from a Mazda MX5 (Miata).

[@EdxGamingx]

How were you able to get the casing for the differential?

[@DougsShed]

I used 10g walled Aluminium tube. However I also show that you can form a tube from Aluminium sheet and rivet the seam.

[@bokicar1]

Dear Sir, do you have a recommendation where to find a sprocket to fit those bolt circuit? If I'm not mistaking it's 5 1/4 inch, which Is strange that is in imperial measures for a Japanese manufacturer.

[@DougsShed]

The bolt circle diameters of these sprockets are exact metric sizes. The sprockets were custom drilled to suit the Mazda differentials. I sometimes buy blank sprockets and bore the centre hole and drill the bolt fixing holes and sometimes I buy in completed sprockets from B & C Express www.bandcexpress.co.uk

[@bokicar1]

@@DougsShed Many thanks for your help

[@paulpvhl1930]

Very generous. I'll subscribe knowing nothing of your channel. Thanks.

[@DougsShed]

Thank you!

[@dan-og4gb]

Hi mate have you got a parts list of all the items you would need

[@DougsShed]

Parts are listed in the description below the video.

[@dan-og4gb]

Thanks I can't find it could you tag me in the list

[@DougsShed]

@@dan-og4gb Just below video click on "Show more"

[@glen_nz]

There seem to be a lot of RX8 bits around lately, do you think an RX8 diff would be a suitable substitute for the MX-5 diff?

[@DougsShed]

I did convert one RX8 differential for a customer. The standard RX8 differential was a Tochigi Fuji type LSD and was not easy to convert and the taper rings for the cone clutches were cracked and broken (very common) and the parts were not available to rebuild.

[@glen_nz]

@@DougsShed ha, thanks, I'll avoid them then 🤣

[@SylvesterOziomek]

Hi Doug. What is the width (flange to flange) difference between 1.6 and 1.8 diffs?

[@DougsShed]

1.6 diff is 240mm and 1.8 diff is 278mm

[@SylvesterOziomek]

@@DougsShed thanks Doug

[@man-united-player]

Hi do you build these up for people if you do id be interested in one

[@DougsShed]

Sorry, I retired 3 years ago and no longer manufacture these units.