LSD diff rebuild 101

In this video we go over the workings of the Limited Slip Differential (LSD) of the Arrma EXB class cars. We pull the diff apart, go over the workings of this new system, and explain the theory and science behind it. Then, we show you how to reassemble the unit so you can get up and running as soon as possible. Come along for the ride as AJ explains the new system.
Music:
Ethan Meisxell: Run
MixKit: Party Robot

[@nelissuh]

Very nice video. I love how you both give a very clear and detailed explanation how to assemble, and in addition, you explain why, so the viewers learn from your knowledge. Thanks a lot!!!

[@AJJAMStudios]

Our pleasure! AJ

[@kevinames5805]

For a new being in rc for a very short t[me I rely greatly what you do with these videos They have helped me a bunch, with in the next i think I am going to build.. Thanks for what you do.

[@AJJAMStudios]

Glad to help 😎👍

[@rweber1971]

This is by far the best Differential video I have ever seen. This man is a master instructor. Very well explained. Thank You!

[@AJJAMStudios]

Wow, thanks! 😎👍

[@cwatson42785]

He has some of THEE BEST wrenching videos in the game and I definitely appreciate him for taking the time to do it as well!

[@Themlpg73]

​@AJJAMStudios Hi. I have a Kraton 6S Exb, the newest version. Do I have also LSD in front and center only? In the manual it seems like it shows open diff front and back. LSD only in center. Maybe I am misunderstanding.

[@Soilhalo77]

Star gears have chamfered edges so one edge is round one is flat. It’s easier to find info about setting thee in correctly when u look for this. I didn’t know this when I bought mine so when I first got it and went through the diffs before running and changing diff fluid, I didn’t put one in correctly as Arrma don’t put it in the “destructions” only online. End of the day it made no difference to drive. I did however go through all the diffs again and make sure they were all in right direction Well explained video for people that are new to this though dude 👍 On a side note I’ve had the front outdrive from the diff come loose a few times and if it’s the front diff u need to take so many parts off it’s a nightmare. It’s not just plastic your screwing in to , there is metal (alloy,steel,whatever) so I would put a dab of blue loctite on just in case it backs out It saves a lot of messing about and xtra work Just saying 🤷‍♂️👍

[@AJJAMStudios]

You appear to have yours well in hand 👍 thanks for the comment. AJ 😎👍

[@nelissuh]

Exactly. For me it was also easier looking for the round edges like in the Arrma official video, instead of finding aggressive/sharp sides. Just a minor remark on a great video. I love your video.

[@JustKeepLivingFPV]

I think if you start yelling none stop you will be at 2million subscribers in no time.

[@ggwbrc]

Hello New subbie from Indonesia 👋 Greetings one remote from Indonesia👋 Watching u'r video with a cup coffe Very enjoy 😍

[@AJJAMStudios]

Welcome. 😎👍

[@ggwbrc]

@@AJJAMStudios thanks 😁🍻

[@89rc_dude33]

This is a hell of a useful video. Everything nicely laid out and a lot of good tips and information. Huge thanks for that video.

[@AJJAMStudios]

You’re most welcome. 😎👍

[@BenJamin-wl8ov]

Love the content!! Helps a ton! Much appreciated

[@philsonnenberg6092]

I know this is an older video but would the Typhon TLR get any benefit from the LSD's? I assume they would fit or would they not?

[@AJJAMStudios]

They will fit and with some fairly light oil they should work pretty well. We have not done this in our TLR but our experience with the diffs tells me it would work. Will it be a noticeable difference, you’ll have to let us know. Thanks for asking 😎👍

[@DoctorPPants]

Thank you for posting this, it answered literally all of my questions about the diffs.

[@AJJAMStudios]

We’re happy we could help 😎👍

[@brucecampbellx]

Excellent 100% instructional video. Cheers!

[@AJJAMStudios]

Glad you enjoyed it!

[@scootersmith4547]

Just a bit of insight, first time here, thank you for the instruction...But, you almost lost me on the way to long intro... on a scale of 1 to 10 for the length10 being 100% original length, i would trim that back to a 5.. easy. Why, i am hard to chase off, and that almost did it...👌

[@RoosterGardens]

I'm not sold on this "LSD" technology. My Kraton will be here tomorrow. Can't wait to take it apart myself, Lol. But I would take an old Ofna Super Torsen center diff any day! And thank you for that screwgun comment! I cringe every time I see people doing that. And, about 90% the reason I don't like buying anything used...

[@AJJAMStudios]

That’s a very good point. You never know how someone worked on their cars. Thank you for the comment. 😎👍

[@Raqiib]

I got mine's in February and all 3 diffs are LSD

[@AJJAMStudios]

Good to know. Thank you 😎👍

[@toomajRC]

nice one thanks!

[@RC_Berserker]

I have NEVER once in my life let anyone else work on my cars 😂 I’ve only let the hobby shop solder on connections for an esc I got from them because it was free and 🤷🏻‍♂️ why not? There’s always video like these to help if you’re stuck and need help. I watched this for the explanation on the LSD functionality because I haven’t had to open mine up yet. Witch brings me to my question. I’ve noticed there are aluminum diff cases. Do these not house the LSD system? My outdrives are pretty chewed up from running in gravel and catching rocks between them and the lower arms 😬 I was thinking I would get new outdrives with the aluminum casings while I strip it all down. So, will I need the shim kit or will the LSD still work?

[@AJJAMStudios]

Aluminum is a fair upgrade. However, I just replace them with stock casings. They are cheap and readily available. Plus they don’t add weight. Let me know which you choose. 😎👍

[@RC_Berserker]

@@AJJAMStudios I’m going to wait on the diffs I guess because the outdrives are still good, just ugly hahaha! I got the hot racing hub carriers for my Talion and was installing them only to realize the axels are too short 🤦🏻‍♂️ looks like the talion is going to get a wider stance once I pick up some Keaton axels today. Oh, but the HR diff housing/bulkhead went on nice! Came with a bunch of screws I didn’t need but 🤷🏻‍♂️ I hope the ears on that don’t bend or strip.

[@nasles1538]

very good video

[@douglasmorrison5599]

Great video.

[@lipoz-n-nitroz4012]

Absolutely phenomenal video, I was wondering if I can use the diffs in an "open" configuration and certainly didn't come here for that answer but what a surprise to find it. Thank you very much! I own 4 of these diffs and it's nice to have options on how to run them.

[@IDORC]

Nice explanation but I still have trouble with the correct (smooth) side of the plates, both sides look and feel the same to me! It gets very frustrating guessing!

[@davidzizelman2061]

Very good video! Just got a kraton 6s exb. Used, but never driven. Everyone tells me to shim the diffs. I’m still kinda confused on how exactly to do that. I wasn’t able to find a video I believe you mentioned you had done on that.

[@josephcaruana9165]

I would put some graphite grease or some kind of lubricant on the input shaft so it will not wear quickly!

[@mikefeit7177]

Hey! I really like your videos about the Kraton EXB and I am considering getting one myself. One question: Can you run the diffs without the LSD plates, as normal diffs, or do I need to get other diffs? Thanks and cheers!

[@AJJAMStudios]

If you check out our LSD diff video we run through all of your options. Hint, you won’t need new diffs but you will need the shims. Thanks for asking. AJ

[@tktk-om8cg]

This is a awesome breakdown in your opinion what's the advantages of LSD

[@Mr.H-m2q]

Great job have you tried all three of the differentials being the same? What do you think about new design you like it better?

[@gboulter]

Not putting tiny smear of grease on the diff drive cup shafts is a mistake. Dry steel on steel not the best bearing.

[@AJJAMStudios]

I get your point, but applying a lube that can hold onto dust and debris only serves to wear the parts out quicker; that's my opinion only. As we build the diffs we get a bit of the lube on them purely by accident as we usually rebuild and do not build from scratch all that much. Plus, the rotational forces on the diff cups is not a load bearing situation as the drive shafts come straight out with very little side pressure. Usually I would agree with the lube idea, but in the conditions we run in, the grit that sticks in the lube only serves to cause wear problems. I suppose a bit of silicone lube or graphite might do the job without attracting dirt, they are a dry lubrication. Thanks for the comment, it is greatly appreciated. AJ

[@gboulter]

@@AJJAMStudios I've never seen any dirt get onto that shaft if I was concerned I would use a dry teflon spray as I do on the CVDs and dog bones.

[@jennifermichelle9043]

Best video ever You explain this perfectly I'm not afraid to work on my diffs now and I'm new to this just got my first arrma fireteam 6s it's still new i need to get battery and charger Just wondering if you recommend doing anything to it before I run it for the first time thanks for the great video .

[@hellraizer4820]

Excellent video! Thank you very much!

[@issaadams1837]

Thank you for your channel as a whole. You are all I watch...

[@Northside910]

I wonder if the talion exb come with limited slip differential in the rear

[@chiasson65]

Good job, nice explanation of the LSD system. Cheers, Kev

[@AJJAMStudios]

Thank you for the comment. I appreciate it. 😎👍

[@Watermoehlen]

That Kraton looks so silly on the Mojave EXB wheels

[@AJJAMStudios]

Yes, but it handles great that way. I do run the stock wheels most of the time. 😎👍

[@VDVC-RC]

I got some for my Typhon for off-road bashing. Handles great!

[@NeighberhoodRC]

Which is better to run with lsd slips or without them ?

[@readeracingRC]

I find out the 2 shims next to the "O" rings. The EXB wants the thicker small shim. I measured out to .05mm. there is also the .03mm shims. i made the mistake and put the thin one in and not the thick ones which makes it to loose and the gears will start jumping and tear up the planetary gears. i went thru my front an rear after screwing up both front and rear gears. i took it out for a bash today with the .05mm shim and it ran flawlessly. not sure if i make sense. but i watch another vid an is what brought this to my attention. Thanks for the video. and "Keep on Sharing"...

[@AJJAMStudios]

Good to know. Thank you for sharing😎👍

[@asfkrs]

Thank you for the video, great stuff. Can you please explain more about the difference between the aggressive and non-aggressive setups?

[@AJJAMStudios]

Sure. To begin with, it is a matter of feel to the driver. The aggressive setup is stiffer and more prone to skidding or locking the two wheels together if the fluids are stiff enough. The stiffer the fluid inside the diff, the less counter rotation the diff will produce under power. In other words, stiffer equals Posi traction if the oils get heavy enough. The opposite is true with the lighter fluids. The lighter the fluids get the more prone to counter rotation the diff becomes. To spell that out a bit better, with light fluids, when you spin one side by hand, the other will counter rotate very easily, thus allowing the rig to spill all extra power to the spinning tire and not to the traction tire. Stiffening up this component (the oils) drives more power to the traction wheel and gives more thrust to the rig. However, this thrust comes at a cost. When you eliminate the over-spin (light oils) in favor of stiffer oils, the rig can become much more squirrely and prone to flipping over or spinning out instead of staying controllable; that's why they usually ship the diffs with lighter fluids from the factory, to make the car more controllable for everyone regardless of your skill level. As far as the plates inside the LSD diff go, there are two sides to each plate and they are different, if you look closely you should be able to see the smooth side and the course side. Always follow the manual for how this should be installed into the diff. With the aggressive setup, the diffs "should" react more aggressively and throw more power to the spinning side while under power; that's the theory anyway. I have not noticed much of a difference myself. As far as I can tell, the fluids make a bigger difference than the plate side you choose. However, this overall view of the customer purchasing these machines is why each car has to be setup for the individual and not as a "one size fits all" solution. The oils that work for me might actually not work for you at all because of our situations, locations, driving styles, and experience levels. The companies that produces these machines are tasked with finding a way for everyone to be able to drive their products or they simply won't sell; that's why tuning is so important. Wow, that was long winded. I hope this helps. AJ

[@asfkrs]

@@AJJAMStudios thank you AJ for the prompt and detailed response! That is very helpful. Can you explain a bit more on why would the car become less stable with thicker fluids? How would this affect steering?

[@AJJAMStudios]

Sure. The stiffer fluids allow the power to be sent to the traction tires without bleeding off the excess. This allows the tires to "all" break traction, which allows for car's possible over-rotation in a corner, AKA spinning out. With stiffer fluids in the center diff, the power is sent to the front and rear of the car more equally which facilitates wheelies while under power and endos during breaking, making the car harder to control in traction situations. A good balance of fluids "can" allow both results to an extent. With the proper fluid thicknesses in each diff the car can hole-shot well, and yet still bleed off enough excess energy to stay manageable. It is up to you to choose the balance you require. And, each car is different and requires the same diligence when working the setup of the diffs. Stiffer is more locked down and less controllable, while light fluids are less locked down and thus bleeds off the excess energy without costing traction but at the cost of the hole-shot. The balance is yours to find. Good luck in your search. AJ

[@tktk-om8cg]

I found another one of your videos on diffs👍👍

[@brokennib1]

Man, thank you so much for this video, I opened mine up to check the diff oil, but was too chicken to take out the plates😄 the exploded diagrams that come with the truck do not go into details, so it can be pretty intimidating, I need to check, but do you cover diff tuning in another video? Can I still tune with oil if the LSD plates are installed? What about the center diff? AAAHH! so many questions!

[@AJJAMStudios]

Yes you can still tune them. The center comes with 100k from the factory. So there is room for tuning. 😎👍

[@justaguyrc6303]

Great explanation video of how this diff goes together and why. I have a talion and I wanted to check the diffs to make sure arrma put enough oil in from the factory before I ran it. I noticed that a star shim was broken and it had half the oil needed. Now I’m waiting for my new parts to arrive before I rebuild this diff. I wasn’t happy that a brand new diff came with a damaged part from factory. It wasn’t worth the effort to have arrma replace a few dollar part. One difference between the Kraton and talion seems to be is the Kraton is setup with the more aggressive diff option. My talion has the other option in all the diffs. Im guessing that will allow the talion to go faster out of the box.

[@AJJAMStudios]

Thanks for the comment, and no the setup of the diffs does not directly affect the overall speed of the vehicle, it's the handling. The setup of the differentials is to get more or less power or handling during acceleration or cornering. In short, it's the setup of the diffs that allows the car to remain controllable for the driver in typical situations. If the car is squirrelly then the diffs are not setup correctly for the situation. If it pushes in the corners then the diffs might need to be looked at. Again, thanks for the comment 😎👍

[@marcoserbach3848]

Best explanation bout Arrma LSD on YT! Thanks you boss!

[@AJJAMStudios]

Thank you. 😎👍

[@prowler-6666]

Hey, Already knew what you were showing here but nice to watch to see I was not missing anything and very well explained.. Great job.. Running an EXB myself and built a hybrid center diff which has been fun to drive so far on a few small test run, give me a shout and ill give you more details on what I have been working on :D

[@AJJAMStudios]

Thank you. I’m interested in your project. Post it and fill me in. 😎👍

[@prowler-6666]

A link to original forum post explaining it, small vid at very bottom of the post. Drives nice tbh. Thread 'A little LSD theory crafting' www.arrmaforum.com/threads/a-little-lsd-theory-crafting.38580/

[@AJJAMStudios]

Interesting idea. At the outset it looks as though it has merit. Now I’m curious. Only using the plates in the front half of the center diff... The idea intrigues me. It sounds like something I would try...and probably will. Thanks for sharing the idea with me. 😎👍

[@prowler-6666]

@@AJJAMStudios Cool, if you do let me know how you get on with it, any feed back would be great :D

[@skeletorrc2583]

Great 👍🏻 video. Super helpful. Thanks! 🍻

[@AJJAMStudios]

Glad it was helpful!

[@josemedrano3836]

So what's the difference between the limited split and the regular opened diff, which one is better for bashing and huge jumps

[@AJJAMStudios]

They are both good for that purpose. The limited slip diffs have larger gearing and are built tough, but have limitations when it comes to the oils they can effectively use. The standard diffs have finer gearing and need to have the spacing checked to maintain the proper shim spacing for durability. They work just fine if the shimming is correct. I've noticed no discernable differences between them where bashing is concerned. However, the limited slip diffs do require a higher maintenance regimen than the standard diffs because of the friction the plates create within the diff itself. If you're willing to put in the effort they should work just fine for you. I hope this helps. AJ

[@24hourgmtchannel64]

A vehicle limited slip has ramps that engage and press harder against the clutches on each side upon slipage. I'm guessing these RC LS units rely on constant friction only?

[@AJJAMStudios]

This type of LSD diff relies on fluid resistance to function. The viscosity of the oils create the drag between the plates and limit the slippage. It is harder on the fluids as they break down faster, but it does work. Thanks for commenting. 😎👍

[@24hourgmtchannel64]

@AJJAMStudios ah, I see. We have a lexus rx 300 which has a rear viscous limited slip. Was only available on the 99 model year. It uses a silicone like fluid and acts like a torque converter so no mechanical contact for Its function. Because of this, it has limited locking action when needed and is probably why torsen type became more dominant.

[@Ryndel]

Super informative video thank you. Do you think a center exb diff swapped into an rtr would be a good idea? I was thinking of putting the exb lsd into my rtr Mojave.

[@AJJAMStudios]

Sure. The LSD system will work as well in the Mojave as in any other car, but there are pitfalls to that system, like a more rigorous maintenance requirement, and the limitations on the oils you can use, but that's not to say it's a bad system, it works just fine and it has larger gears which make it a tough diff. Just be ready for the way were designed to work, and you should be fine. Best of luck. AJ

[@Ryndel]

@@AJJAMStudios thanks so much!

[@TiberiusCat]

Really great educational video!! Thanks so much!

[@AJJAMStudios]

Glad you enjoyed it!

[@JohnSmith-lk8me]

Now what part of this very informative video deserved a thumbs down.

[@rickyturner2742]

The intro, it's a tad long

[@seth9145]

Loving your vids. I am comparing the EXB to the KS EXB and I haven't found a video of yours with the bigger KS EXB so I am assuming you only have the EXB so far? Really wanted your take between the 2 particularly the durability because the size is of course an obvious difference.

[@AJJAMStudios]

You are correct, I only have the 1/8th scale exb. Thanks for the comment. 😎👍

[@seth9145]

@@AJJAMStudios Hope you grab it someday. Your vids are so informative, thanks!

[@Northside910]

by taking out all of the star disc the front and rear exb differentials can be used as open differentials?

[@AJJAMStudios]

Not without thee shimm kit for support. We cover this in the LSD diff video. Thanks for asking. 😎👍

[@ovidiumache8066]

last night I also ordered exb, I ordered it in England with some upgrades that you recommended (I couldn't find wheelie bar) I can't wait to bring it home :))) King regards from Romania

[@AJJAMStudios]

I think they discontinued the wheelie bar. Thanks for the comment. 😎👍

[@Soilhalo77]

@@AJJAMStudios still readily available in uk

[@andrewlim7058]

Awesome Video mate, u are a legend!!! I was wondering if the LSD plate setup on maximum or minimum changes the durability of the EXB diffs and if there is a preference for the durability. Thanks again brutha!!

[@daltonboucher8162]

Wow thanks for sharing 👍 I was in a bind about how things worked in this new diff

[@AJJAMStudios]

Glad we could help. Thanks for watching 😎👍

[@maddwills.8073]

Great breakdown of building this one ☝️ What are your thoughts about how it preforms vs a open diff that has been tuned for your driving style? Can you install a lsd into any arrma rc? I have a Mojave and picks this one based on some of your reviews and how I noticed it to be able to put the power down without just wheeling everywhere which I really like, is truly like you say when calling it a “guided Missile” 😀 and I know a large part of this is wheelbase and and and but also the relatively light center diff oil and I love how it drives box stock but being a tinkerer can’t help but think there’s some room for improvement but also keeping it able to stay grounded, initially I was thinking about trying some 300k-500k in the center diff but now you have me thinking about trying a lsd in the center?? 😂 can you further tune the lsd with different fluids also? Anyhow thanks for the videos man!

[@JohnSmith-lk8me]

Back again...Thanks

[@paulnorton7444]

Excellent 👍

[@smokinjoe909]

great video thanks for all you do.

[@AJJAMStudios]

My pleasure!😎👍

[@chris198004]

good video but those are not planetary gears!

[@AJJAMStudios]

Thank you

[@daltonboucher8162]

Aj just open my rear diff has those plates did I hear rite arrma says the rear is open ?

[@AJJAMStudios]

Open is a matter of oil thickness. Thin oil in the diff is open, thick oil is not, heavy, 1 mil oil is locked. The plates do not determine if a diff is open or not, the are just the limited slip portion of the system. Thanks for asking. 😎👍

[@daltonboucher8162]

Ahhh OK watching the video it sounded like there were no plates in rear my bad sorry

[@AJJAMStudios]

Have a great day 😎👍

[@haroldbascom5866]

I enjoy your channel and regard you an expert. As such, I have a question about my Arrma Mojave 6s that I bought like a week ago. I run it on my backyard off-road, grass-dirt track that has aggressive turns and vicious sweeps, and I drive my Mojave always set at 100 percent throttle. (It's also hot when I run.) The batteries I have in it are two 3s Spectrum 5000 may, 50 c Smart batteries charged with my S-21 Smart charger. The issue is, my run times: it seems to be dropping off on consecutive runs: The first time I got 15 minutes. Then it dropped to 11, then it dropped to 9 minutes. Can you tell me why this is happening? Thank you.

[@AJJAMStudios]

The way I usually go after issues like that are: first, pull the pinion and roll the truck back and forth to feel for any binding. If the truck rolls freely then spin up the motor, no pinion, and listen to it. If it spins up good then reinstall the pinion. Then I would consider the batteries. Even new ones can go bad. If you have another RC to test them in I would do that. If not, run different batteries to see if the results are the same. These tests should show you where your issue is. Let me know what you find out. AJ

[@johnnydavis8489]

This is the best explanation of the lsd plates ! Thank you. Do you prefer it with the lsd plates or open diff with thicker diff fluid on Kraton exb 6s ? Thanks for ALWAYS providing awesome content. You’re the best in the business

[@AJJAMStudios]

Our preference here is open with adjusted oils for thickness. Easier, lasts longer on an oil change, and there's simply less involved to wear out and cause issues.

[@justinflud3415]

Where are you located

[@AJJAMStudios]

Up in the inland northwest.

[@whistlinlipo]

Been waiting for this one! Thanks AJ

[@AJJAMStudios]

You’re welcome. This one took a while to produce. 😎👍

[@arnoudwalrecht8479]

great video. trying to get hold of your 'chirurgical' tool. even with small pliers its harder to work on the parts:) any tips?

[@AJJAMStudios]

EBay search forceps.

[@malicrni2861]

Hy...my new kraton have minimum efect on lst plates in rear diff and max efect at the front diff...is this ok or it should be the same set up on the rear and the front diff?thanks

[@AJJAMStudios]

If you like the way your rig handles, it's okay that way. But if you need something different then adjust it to your liking. The diffs don't have to be the same, each one is tunable. As far as the LSD system goes, the plates only affect the rotation in the same way if the oils are the same consistency. Thanks for asking. 😎👍

[@seb.9775]

hi , just rebuilt mine following your video . mine is really rough , if i try spin one outdrive by hand it dont budge , if i move both it does but still rough , is that normal?

[@AJJAMStudios]

No. That is usually caused by not syncing the gears as you build it. Make sure the planetary gears mesh properly before closing the diff. Also, as you close the diff be sure the gears move smoothly. This should fix your issue. Let us know if this helps. AJ

[@azliaziz3798]

whats the impact if I use a heavy diff oil with the lsd diff…

[@AJJAMStudios]

Heavy oil reduces the effectiveness of the plates. At that point standard diffs work better. The plates in the diff need looser oil so they rotate against one another. Heavy oil works like glue, sticking them together. It is hard on the parts and is likely to cause issues in the long run. Thanks for asking 😎👍

[@azliaziz3798]

@@AJJAMStudios tq… what would be a good starting point for diff oil..

[@azliaziz3798]

@@AJJAMStudios hi again I plan to built a lsd plates for my losi 5t as it has an open diff now what would be a good material to start with…. would a steel plates work well or a copper plate just a thought thxs again

[@deanbell6003]

Hi what is part number please

[@AJJAMStudios]

Which part?

[@deanbell6003]

@@AJJAMStudios to slipper parts

[@fatcatdan65]

Are the diff cases all the same size in the kraton

[@AJJAMStudios]

Yes. Front and rear same. 😎👍

[@fatcatdan65]

@@AJJAMStudios what about the center

[@fatcatdan65]

I have a kraton I am going to beef up on the diffs

[@AJJAMStudios]

Center is different