Arrma Diff Shimming (Kraton EXB)

[@jerryvolpini7987]

A lot of people have no idea how to shim a diff (or that they even need to do it!) but they will now! Excellent video! 👍

[@robsmith1975]

This is my one stop shop for tech tips/walkthroughs.

[@nerdly44]

This is exactly the video I needed to see. I bought a used Kraton 6s V4, and found that the front main gear had 6 teeth stripped off it. New gear has been ordered, and I will be sure to shim the outdrive bearing this time.

[@seanconrad3574]

Thanks so much for this. Great video. I am returning to the hobby after 25 years and I have a new EXB I just picked up. I read a lot on the Arrma forum but your video is excellent and I learned a ton. I knew what the issue was but you showed me how to check and find out if I need to shim and where/which side. Also providing a rough estimate on the equivalent oil weight of the LSD plates is great. Ordering shims and I’ll check, shim (as needed) and refill my diffs before I run it. I have time while I wait for my motor and ESC. Thank you!

[@RazorRC]

you're very welcome, and welcome back to the hobby!

[@larsoost3901]

Will the diff last long with the shimming and oil change?

[@seanconrad3574]

@@larsoost3901 Definitely- but that’s only if you have a first-run EXB. They identified that issue and the EXBs now come with a new spacer behind the sun gears that resolves this issue. No need for all of this now, if you buy a Kraton or Mojave EXB you can just run it out of the box with no issues.

[@larsoost3901]

@@seanconrad3574 Great! Thanks mate

[@sixstar2067]

I have a v4 Kraton, Arrma have been having issues with these diffs in the 6s Kraton and Outcast basically since they came out. If they upgraded the pins that retain the sun gear and made the sun gear thicker it would solve a lot of these problems. The Typhon and Talion have less of an issue with this because the tires have less mass, which puts less strain on the diffs. Thats also why the Typhon and Talion have straight-cut outer gears while the Kraton and Outcast/Notorious have spiral-cut outer gears. Shims are a must for any Kraton or Outcast but a simple modification to the sun gear and retention pin would solve this issue and make shims unnecessary. There are videos on KZbin that show how to make tool steel retainer pins and this is a big help if you're splitting sun gears like a lot of guys. Just sharing my experience and knowledge on this topic. I hope it helps someone save a lot of frustration.

[@candybutcher8662]

is shimming your diff a permanent fix for grinding of gears? i want to get in the hobby rc world , I just have the Maxx v2 i wanted buy an arma but they have diff problems!

[@mikescallon4288]

I want to thank you for this video. I have been into the rc hobby for a little over a year now and am getting better at working on them, particularly Traxxass model. Arrma vechiles not as much and I was having a difficult time trying to figure out how to install the shims on this new Talion I just bought. Definitely a gear mesh differential issue of some sort with this vechile right out of the box. I have owned Arrma Tyhoon and Bug Rock in the past and neither sounded this loud and loose. I now know exactly how to install them so thanks again! Hope it helps...

[@styleyriley]

All 3 of my diffs were low on oil, I filled them all up and then my rear diff gears went skipping. Replaced with new gears. My plan is to just put one of the LSDs in the rear. Subbed

[@paulclancy2404]

Me too but they on back order so going try one older one possibly v4 in middle lsd front back

[@paulclancy2404]

Where you get new gears i waited on hold for 2hrs i didnt know what ask for they don't exactly throw parts at you haha open diffs on backorder i didnt think ask for lsd

[@styleyriley]

@@paulclancy2404 From Horizon Hobby part number ARA310985. This will be for the stock open gears for the rear. You can also order ARA310984 if you want to convert to LSD. But the complete LSD diffs are not available yet.

[@paulclancy2404]

@@styleyriley thank you I should've been more prepared talking to horizon ,

[@paulclancy2404]

@@styleyriley thanks I think be easier just order parts. I happy horizon giving me v4 diff . For now or use open in middle lsd front back , may feel like v4 tho 🤔

[@jakobsndergaard3071]

Thank you Razor RC! Just what I was looking for. Keep up the good work - I am learning a lot from your videos 👍 👨‍🔧 Loving it!

[@stevejenkins6045]

Thank you. I just saw your videos recent,and your tech stuff is incredibly helpful and well presented

[@RazorRC]

Awesome, thank you!

[@cl-audio322]

Love how to maintenance/repair videos.

[@readeracingRC]

thank you for the very informative video. its not just the Kratons. i have the issues with my outcast. Turns out it was my bad, i had switch shims with a different diff and didnt realized there was a difference. as soon as you came to the shim on the inside, that's when i had the big "Ah-Ha'. solved solve my prob. thank again brou. keep up with the video's. im trying to watch all of them.

[@user-ud2tv6og7k]

I had a clicking diff in my helion avenge mt10 and I just used a ball bearing cover as a shim and that worked great.

[@craigpoer]

Im getting ready to buy another ring and pinion. I keep stripping them. I have shimmed before but just cant seem to get these things bulletproof. Thank you for the most descriptive I've seen on KZbin.

[@pum4542]

Thanks MEN i now repaired my arrma

[@andrewlim7058]

thanks alot mate, I've had endless problems with my outcast exb, didn't even run a full pack. I think I've pulled apart my rear diff bout 8 times now😂

[@earlmarshburn4787]

Great overview of these issues with all of the kratons..

[@RCDUDE81]

Great vid bro!👊The LSD new diff setup is a huge advancement for Arrma! Props to taking time to go over some importance's especially addressing the rear!👍🚀🤘🤘

[@paulclancy2404]

Rc dude , you think I should use v4 in middle use lsd parts to repair the rear till I can get parts i really didnt have play have all 3 shims with v4 i made pretty indestructible except front rings so thinking the strongest set up be lsd front back open in middle what you think brotherman

[@RCDUDE81]

@@paulclancy2404 Yes that should work! Handling may change a tad but will work until you get parts in! Jason did show a diagram of fitting the LSD plates for less action. Bash on buddy!

[@RazorRC]

thanks!

[@dublinbashers8367]

dude your videos are so great, thank you so much for the amazing advice. keep up the awesome work.

[@sonar0085]

Purchasing mine in Oct hopefully they have this resolved ASAP

[@rsoul7282]

People here complaining that this is necessary, guess what, if you are running big power and jumping these things, at some stage you are going to have to open things up and maintain them. If you can’t work on your RC yourself you are probably not going to enjoy the hobby, or have a model that is running for very long.

[@SosopChabot]

God forbid you have to do maintenance on a plastic toy that does 70mph, right? This is by far the least maintenance demanding or break resistant r/c I’ve ever had. Some people just like to whine and are not realistic...

[@eddieroadrunner6691]

R Soul my exb had a light run on grass no jumps was very gentle with it only running around about ten minutes rear diff went never been so happy to get all my money back

[@paulclancy2404]

Man u the man with part #

[@raincntry2657]

Absolutely perfect. Thank you!

[@jasondearden1394]

Great video

[@RazorRC]

thanks Jason, been enjoying all of the updates Arrma has been making, great stuff!

[@kevonrcguy2205]

U guys need to do better this not good

[@YesSir-hk9ys]

Thank you, just bough a talion 6s and the guy said he changed the dif to a new one but it had that clicking sound im gonna do this tomorrow to see how it works out

[@burmesebeef]

thank you for posting this informative video. Is there a need to shim the center diff?

[@based_will]

Damn, I was about to pull the trigger on an EXB till I saw this video. Just sold a v1 e Revo with all kinds of diff problems, I don't wanna mess with that again. :(

[@SosopChabot]

Really??? I’ve been bashing the shit out of mine and many countless of other people doing the same with NO PROBLEMS. This is either fine tuning of he got the 1 out of 500 that needed this. The exb is by far the best and toughest thing out there, I can’t believe the beating it takes and still doesn’t brake...

[@saltylocal6917]

Superb video!👍🏽 Does the Kraton V5 RTR also need shimmed? Any out-of-the-box recommendations/tips for a newbie who’s expecting my RTR within the next few days? Many thanks!

[@johnsorensen5758]

Nice vid razor rc 👍fyi when you were spinning your front shafts I noticed your passenger side driveshaft is bent 😀👍

[@johnisanon]

I see that as well.

[@RazorRC]

thanks 🙁

[@jasonbudd2950Jag]

Thanks for sharing buddy. Very informative. 👍

[@paulclancy2404]

Definitely more resistance with lsd , i was worried taking 10k out for 60k 200k 30k made really tight , but I try following Rich and Eric

[@DoRC]

3:32 nice bent axle shaft...

[@seanconrad3574]

Yeah in the first run video that’s the wheel he hit the steel post with. Watch the first run video at 9:05.

[@phillybrc]

Excellent information . Thanx

[@JOHND_RC]

GREAT INFO!!

[@earlmoorhead5555]

I agree three diff way to much I’d like to keep some power in the rc I really loved the way it handled compared to the v4 Kraton appreciate you sharing as I had all the shims in mine but it still had to much play and broke 💯💯🔥🔥🙏🙏🙏

[@jasondearden1394]

Earl Moorhead weren’t you running 8S? Looked like a wild animal in the video you posted 😆😁

[@earlmoorhead5555]

Jason Dearden yes one was 8s castle system and my first bash with the ExB vs v4 had the blx 6s system in it to compare both rc cars 💯💯🔥🔥

[@ImHedgess]

You had two bigger shims and one small shim by the looks of it meaning you only had 0.6mm instead of 0.75 per side

[@earlmoorhead5555]

Oliver H yes one side measurement was ok the ring gear side way off it was 6.5 so I added two small and one large shim to that side and added think fluid 200 k 👍👍good eye 👁💯💯

[@yaffajaff]

Great video 👍👍 question... at 6:40, was the visible shim in the packet removed from the rear diff? It looks like it's prematurely worn. Does it feel it? This is my worry with using LSD planetary gears in the open diff setup

[@oursostv999]

499 euro and you have to buy other part a shame

[@WestOzRC]

Hey dude. Great video and explanation. I have the Mojo EXB and found that mine doesn’t have the small shim between the LSD plates. Also did you set your center and front diffs to maximum affect? Subed ya. 😎🤙🏼

[@MattHarris89]

Why not put a LSD in the rear? I'm an absolute noob, trying to learn. Wouldn't you get better power to each wheel?

[@RazorRC]

it helps push the truck forward in a straight line, but hurts it when it goes around a corner.

[@goreyboggs]

What fluid do you recommend for the Natorious. I would like it to kind of keep the front wheels on the ground lol it’s a wheelie machine

[@fbiagent3399]

How's that Hobbywing 150A doing?..

[@rebelliontotyrantsisobedie5602]

Hello Sir - I have a new Kration EXB coming in April 2022 , could you please tell me which shim kits to I need part # ARA709031 , ARA709060 or ARA709059 or buy them all?

[@NeighberhoodRC]

What diff fluid is good ? For front and rear diff ??

[@Joe-no5dj]

Whats up with that? I've heard other people say you should shim the diffs before the first run. It's the only reason I never got a 6s arrma.

[@pk52ne]

Hey bud, both my shim packs I ordered came with qty 8, I think you got shorted.

[@TheTylerjoy04]

Once I Have My EXB, I Should Shim My Diffs Right Away As Soon I Open The Box? It's On Order..

[@gregladner6992]

Great great video, so clear. Question though, it looks like the shims got very bend when pushing with the screwdriver into the case. Did they or does it matter ?

[@RazorRC]

Yeah, you definitely need to make sure they go on cleanly and straight.

[@chantelleweightman9713]

And people complain about cheap rc cars being sloppy. For arrma this is disgraceful where is the quality control. It shouldn't be hit or miss with these types of cars.

[@eddieroadrunner6691]

When you checked the diff for play you had the covers off can you still tell if there is play either with the covers on

[@jracer7189]

My outcast is slipping gears and have rebuilt diffs with thicker oil and shimmed them between the bulk head and diff on the front and back diffs and it’s still slipping not sure what it could be other than the pinion inside the bulk head is loose or I need to shim inside the diff inside the gearing

[@KurtsRCs]

Great info

[@leograph5045]

What I need to do? My rear diff is clicking. And I bought ARA311094. Is this right?

[@daveneron9320]

i had a lsd diff in the rear and blew it up too, gonna make sure to shim the next one now. shouldnt have to do this on a week old rc

[@DoRC]

This part of the video about shimming the whole diff is kind of half right. You really need to remove the center driveshafts and axleshafts so you can feel the clearance between the ring gear and pinion gear by rotating them against each other. If you just add shims to remove any side to side freeplay you risk too close a mesh between the ring and pinion which will cause drag, heat and eventually chewing the gears up. The proper way is to add shims until you don't feel any freeplay between the ring and pinion (with the diff housing put back on) and then remove one to get just the right amount.

[@larsoost3901]

Will the diff last long with the shimming and oil change?

[@ThrunRC]

Thank you very much for sharing this. Great work, keep going. Subbed :-)

[@jester1703]

Hello I have a question for u I'm looking for a rtr for the track (1/8 buggy) I understand kits are the way to go but if u had to get rtr what would you recommend

[@chadkyletheman41]

Can’t find any 1/8 buggy race videos to ask this question on?

[@jester1703]

@@chadkyletheman41 whats the difference were I ask? he is a good source buddy

[@paulclancy2404]

Excellent 👍👍💯

[@glaanon4225]

Which Kraton EXB is it ? 1/8 or 1/5 scale ?

[@skeetskeetonu6928]

So I Have A 6s Blx V5 Kraton.So When I Hit The Breaks it Makes A Clicking Noise Not loud but enough to notice.. I did put some scorpion belted tires on it but I would think the truck would be able to handle them tires they are smaller than the stock. Where do you think this issue is coming from it's only when I hit the brakes Thanks ...

[@skeetskeetonu6928]

It's loud enough to notice

[@NepDouble07]

Are you able to drop these diffs into the RTR vehicles without changing the pinion (that mesh with the differentials ring gear)? I know the center diff isn't a problem, but the ring gears are slightly different for the front and rear.

[@RazorRC]

no, the RTR kits use a different sized pinion/ring gear size

[@NepDouble07]

@@RazorRC Good to know, because I was thinking about upgrading the diffs in my v4 outcast to the exb diffs.

[@NeighberhoodRC]

Plastic steering blocks sucks be losing steering waiting to upgrade to aluminum ones

[@NeighberhoodRC]

Well for notorious 6s v5 blx

[@JosePerez-cf1ow]

Can you make the rear like the front one? Limited slip

[@RazorRC]

yes

[@based_will]

Damn, if I had only watched this video/bought an EXB a month ago. Now everything is backordered till who knows when..

[@pewterngold]

I can’t believe Arma rolled out a brand new rig with diffs that need to be shimmed.....again. And then they have low oil levels as well?? Terrible QC.

[@sixstar2067]

The 6s Kraton and Outcast have had problems with diff failure since they were released. The EXB is getting a lot of attention because it's a new version and the LSD diffs are novel to Arrma owners. It is not so much a QC problem as much as a cost-cutting measure. The 6S line all use the same internals on the diffs. The Kraton and Outcast need much tighter tolerances due to higher mass in the tires and heavier weight overall compared to the Talion and Typhon. If Arrma made thicker sun gears for the Outcast/Notorious and Kraton and used slightly thicker retainer pins for the sun gear these issues would not be happening.

[@pewterngold]

Greyson Skeen....I see your point. I have an early version Outcast that gave me fits with all the shimming the diffs needed. Completely took away from me enjoying that rig even though I still have it. Guess I’m at the point of simply throwing my hands up with Arma diffs. They’re aware of the problems, yet it continues. And now with a $470 roller that carries the title EXB? Apparently Arma is replacing the rear open diffs with lsd ones. Problem is that they’re on back order. Makes for a failed new model launch IMO.

[@sixstar2067]

@@pewterngold I've shimmed my front and rear diffs on my 1st maintenance teardown. I did have a broken pin that luckily did not split the sun/planetary gear in half like what usually happens with broken pins. The pins that Arrma uses have evidently been updated to be wider in diameter at some point in the last 6 months or so but for a very long time they were about 0.25mm undersized, which left a lot of slop with the way the sun/planetary gets retained on the drive cup shaft. This caused a lot of failures and seems to me to be the most common failure mode. Second is the satellite gears inside the diffs breaking teeth which gets solved by putting 1 or 2 shims behind the pin and sun/planetary gear inside the diff on both drive cup shafts. Least common diff failure ( though still happens too much imo) is the outer gear teeth or the teeth on the crown/input gear breaking on the diff input or outside of the diff itself. This is solved by 1 or 2 shims on the crown/input gear to push it into the bulkhead a bit more for better gear mesh. Also if it's really bad you can also do what was shown here with a shim on the outside of the diff carrier bearing on the outer gear side. Rich Duperbash did an excellent video on how to do all of these. The hard part is getting all the shims for a fair price. I had to order Tekno shims for my diff internals and while it came with everything needed to do all 3 diffs, the Arrma branded shims are a bit cheaper if you can get them.

[@pewterngold]

Greyson Skeen....great advice. Thanks for your help! Good luck with your EXB. I hope you get it running strong 🤘

[@sixstar2067]

@@pewterngold I've got a v4, not an exb but I talk with guys on the Arrma forum a lot about this very topic. I'm hoping to get an EXB soon though.

[@MrPontiacfever]

i feel you'd have better luck with the straight gearing in the differentials by them being spiraled the chance is greater for them to slip its simple physics.I plan on taking mine out soon as it arrives at my doorstep.Its just a well planned money pit to me.

[@Hungrybird474]

Getting a kraton v5 shortly .

[@SamCyanide]

do you still need to do this for the v5 exb? I just ordered the roller brand new, I'm gonna be running a mamba monster x 8s but with 6s battery. I don't want to crack the diffs open cuz nobody has diff oil in stock - it looks like you can shim from the outside but still edit: it looks like its really easy to check so thats good. I'll check it.

[@DeRock401]

Did some say LSD?

[@keekay_cg32c7.r2]

Is one million wt diff oil okay for the front and rear?

[@RazorRC]

no, stick to 10k-50k at the most

[@ParcoUpchurch]

@@RazorRC You running stock weight on your K6S EXB I'd like a little drift action when I am in the dirty. Mine is still new unopened and I need to check the diffs was thinking 60/100/30 I am assuming until I open it the rear is an open diff. What your thoughts and what you wt you ran when you drifting in the baseball part after swapping around the front LSD?

[@ftnwo7829]

So why doesn't arrma just shim it at the factory? Of course those shims are free? There fuck up.

[@BlvlWmpower]

Maybe they were running the manufacturing machines to a lazy tolerance to keep it within the shim, not shim threshold. I'm sure the robotic cutters have blades or bits that need to be replaced after so many parts are made. It probably was costing them a fortune to keep things pumping out, but hey, more parts will be ordered.

[@paulclancy2404]

I have such little play I guess be better to have 2 small fatter ones im sending a picture to horizon today , i had asked send v4 diff just bc he didn't have lsd they on back order but I should've taken diff apart first bc probably have gears. Or the shimms going look now we get to bottom this exb drives awesome 👌 like I'm riding my dirtbikes.

[@deontay79ify]

Spider gears are the issue not ring gear

[@franktheyeatmaster5242]

Ya front left drive shaft is a bit bent

[@BASSstarlet]

This is disappointing. Im not willing to strip apart a brand new RC even before the first run :/

[@leer4009]

I know the vid is ten months old but your left front axle is bent .

[@onemansvideos2134]

This should have been sold as a kit

[@paulclancy2404]

Now I see what they meant. we need .08 I think 🤔

[@brisfocus3648]

other fix is make the rear diff LSD like the front...

[@dondavis9249]

Gotta wait tell next week to pick my kraton up my dam gf had me buy her all kinds of shit from the mall today.

[@DronePlayground]

👍👀🇭🇷

[@cliffjones9922]

My diffs seem really tight just looked to shim them but no real need as yet. Perhaps theyve improved it on later models? What diff fluid would you recommend running? Got mine with a HW max8 with 2200kv motor. Opened the center and shocked to find it was near dry and the front and rear just about half full

[@jamesblake1848]

Something you shouldn't have to do in the first place SMH

[@eddieroadrunner6691]

Your spot on when something is faulty you send it back not try to fix it arma will never get there act together when you have fools trying to fix there mistakes

[@mrbutchee1]

Talk about late to the game. 3y

[@DieForMyDOGs]

Wondering to buy 2 of the front exb diffs for my notorious. Dont want to mess with these shims. What do you think? Why is that rear diff dont have these lcd plates? Is that important to not have them in the rear?

[@RazorRC]

the open rear diff helps it turn better. the LSD forces the truck to go straight more.

[@DJCHURKLE]

Thanks man!! Great video.

[@benniullrich2237]

Can I use also one Front diff as a rear diff?