Kraton Diff Maintenance

[305HemiGuy]

Hey guys, so I started hearing a clicking coming from the rear end. Figured I might need to add a shim to the rear diff, so I opened it up for maintenance. Upon opening I found that it was caked full of crud and had absolutely no grease in there. I bought this as a second hand roller fwiw. I see there's one shim installed already, but before I add the second the shim I want to get things all cleaned up & greased. If a second shim and grease don't fix the issue, then im just going to put a whole new diff unit in this sucker. What grease do you guys recommend putting in the diff case?? Thanks.

 

[gotnitro]

See all that crap in that cup, that’s dried grease. Red tacky grease and less is better, otherwise you’ll open that diff back up and it’ll look the same.

 

[305HemiGuy]

Holy moly, is that what all that crap is?! Wow. I'm otw to Walmart now, as they're the only semi hardware store open today lol. Hopefully they have the red tacky grease, I've seen a few other members here recommend it.

See all that crap in that cup, that’s dried grease. Red tacky grease and less is better, otherwise you’ll open that diff back up and it’ll look the same.

 

[Senton_Prime]

Geez Louise, you ever give that thing a wash!! I see fast Eddy bearing's in your near future.. like before your next run, future!!

 

[305HemiGuy]

Geez Louise, you ever give that thing a wash!! I see fast Eddy bearing's in your near future.. like before your next run, future!!

Take it easy on me man, it was a "gently used Kraton roller with freshly rebuilt diffs" Ebay special

 

[parcou]

Hey guys, so I started hearing a clicking coming from the rear end. Figured I might need to add a shim to the rear diff, so I opened it up for maintenance. Upon opening I found that it was caked full of crud and had absolutely no grease in there. I bought this as a second hand roller fwiw. I see there's one shim installed already, but before I add the second the shim I want to get things all cleaned up & greased. If a second shim and grease don't fix the issue, then im just going to put a whole new diff unit in this sucker. What grease do you guys recommend putting in the diff case?? Thanks.

View attachment 291569

Red and tacky is what I use on the outside of the diff

One shim on the ring gear side, as pictured. If you still get side-side movement, try two. You can also shim the input gear that is spinning the ring gear, but that is a different subject and more of a focus on gear mesh between the two.

 

[305HemiGuy]

Red and tacky is what I use on the outside of the diff

One shim on the ring gear side, as pictured. If you still get side-side movement, try two. You can also shim the input gear that is spinning the ring gear, but that is a different subject and more of a focus on gear mesh between the two.

I was able to find & apply some red tacky. The ring gear side already had one shim, so I added another for a total of two. I took it out for a test drive after I put everything all back together and it's still clicking So now I'm thinking it may be the front diff. If I hold the car in my hand and give it a throttle it doesn't click, same thing if I spin the wheels on the work bench, no clicking. I can only hear it when it's on running on the ground. I'm almost to the point of just buying new front & rear diffs.

 

[Senton_Prime]

Can u get a video of it

 

[305HemiGuy]

Can u get a video of it

I'll see if I can get it on video tmrw. When it's going slow you cant hear it, but when it's running wide open, that's when you can clearly hit the click. I'll probably have to sit my phone down on the grass and then drive by the phone at speed.

 

[Surchaufeur]

Always put grease around the bearings and inside the gearbox on the edges. I have been doing this since the very beginning and i have yet to have grime getting into my diffs

See all that crap in that cup, that’s dried grease. Red tacky grease and less is better, otherwise you’ll open that diff back up and it’ll look the same.

I doubt that is what it is. I also use red n tacky on pretty much anything

 

[gotnitro]

Always put grease around the bearings and inside the gearbox on the edges. I have been doing this since the very beginning and i have yet to have grime getting into my diffs

I doubt that is what it is. I also use red n tacky on pretty much anything

Did you notice how clean his ring and pinion are? That’s because all the grease flicked off and is now all dried up along with I’m sure dirt.

Everyone always talks about how bad diffs look internally after a few packs and guess what, they are. They ALL are. Diff’s are a general maintenance part. After one bash session or a few packs in some cases.

Less is better, one throttle stab and all that red grease has now painted your whole internal diff and nothing is left on the ring and pinion but a thin lawyer of film grease.

 

[pstill9302]

Did you notice how clean his ring and pinion are? That’s because all the grease flicked off and is now all dried up along with I’m sure dirt.

Everyone always talks about how bad diffs look internally after a few packs and guess what, they are. They ALL are. Diff’s are a general maintenance part. After one bash session or a few packs in some cases.

Less is better, one throttle stab and all that red grease has now painted your whole internal diff and nothing is left on the ring and pinion but a thin lawyer of film grease.

305HemiGuy.
You need a new ring gear at least, and maybe a pinion. See how pointy your teeth are on your ring gear? The dirt and crud ground the teeth and now w/o replacing it will always click because it is not engaging properly. I went to exb diffs front and rear off Jenny’s since they have larger contact between the ring and pinion, and also got the Basher queen bulkhead gaskets for between the chassis/bulkhead. Does ok now keeping crap out (at least more manageable to service before destruction.) Went through what you show/explain twice (having to replace the ring gear) before making this change.

 

[305HemiGuy]

305HemiGuy.
You need a new ring gear at least, and maybe a pinion. See how pointy your teeth are on your ring gear? The dirt and crud ground the teeth and now w/o replacing it will always click because it is not engaging properly. I went to exb diffs front and rear off Jenny’s since they have larger contact between the ring and pinion, and also got the Basher queen bulkhead gaskets for between the chassis/bulkhead. Does ok now keeping crap out (at least more manageable to service before destruction.) Went through what you show/explain twice (having to replace the ring gear) before making this change.

Thanks, that's great advice. I did look into the EXB diffs b/c I know the EXB components are more solidly built. But I was a little confused about the LSD aspect. How do the EXB Limited Slip diffs perform versus the regular RTR diffs? What effect will the LSD aspect have on the power delivery to the front & rear axles? If you're not too sure I'm sure one of these other knowledgeable folks in here can chime in.

 

[pstill9302]

Thanks, that's great advice. I did look into the EXB diffs b/c I know the EXB components are more solidly built. But I was a little confused about the LSD aspect. How do the EXB Limited Slip diffs perform versus the regular RTR diffs? What effect will the LSD aspect have on the power delivery to the front & rear axles? If you're not too sure I'm sure one of these other knowledgeable folks in here can chime in.

Yes there’s plenty of posts on this topic. I do the “open” diff setup rear and mid range lsd setup front. 30k in both (front acts more like 50/60k.) 300k center, still standard diff there. The gaskets helped a lot (I put red sealer on as well) with keeping crap out.

 

[Surchaufeur]

Did you notice how clean his ring and pinion are? That’s because all the grease flicked off and is now all dried up along with I’m sure dirt.

Everyone always talks about how bad diffs look internally after a few packs and guess what, they are. They ALL are. Diff’s are a general maintenance part. After one bash session or a few packs in some cases.

Less is better, one throttle stab and all that red grease has now painted your whole internal diff and nothing is left on the ring and pinion but a thin lawyer of film grease.

Been on the same exb diff For 2 years
The exb diffs are a lot stronger than the RTR diffs. If you don't want to mess with the LSD feature just get this https://www.arrma-rc.com/en/product/diff-shim-set-fits-29mm-diff-case-3-diffs/ARA311094.html if you want to go the extra mile get an aluminum rear gearbox and ur diff issues are going to be a thing of the pass. Thats why i only jumped on the 6s arrmas when the exb came out. don't forget to shim the crown gear of course

 

[parcou]

Thanks, that's great advice. I did look into the EXB diffs b/c I know the EXB components are more solidly built. But I was a little confused about the LSD aspect. How do the EXB Limited Slip diffs perform versus the regular RTR diffs? What effect will the LSD aspect have on the power delivery to the front & rear axles? If you're not too sure I'm sure one of these other knowledgeable folks in here can chime in.

Before jumping diffs, try to resolve this. I am sure this is a simple fix once found...you may be just fine on the RTR diffs.

Meaning if they are serviced and shimmed well, they can last and work great. Both the F/R diffs make sure they are shimmed with no side to-side movement. Also, I think it is also important to check the input gear to the diff. So having too much mesh or rocking between the gears and under stress/bashing, you could get some slip between the gears. So I also like the remove the front and rear assembly to look at it from the bottom and see how well the input contacts the diff ring gear and shim as needed. I will post a video below.

All your diffs F/C/R check the internal spider gears are turn no teeth missing. Once the diff is assembled, you should slightly feel the spiders turning as you turn one of the outdrives. If I can turn the outdrive and feel no spider gear feeling as if it were air, personally, I do not like that and recheck the mesh.

6S diff gears are not LSD but can work great. Infraction, Fireteam, TLR Typhon, Kraton v5, all gears are shimmed perfectly and spot on...no clicking or issues bashing.

 

[305HemiGuy]

Thank you all, I appreciate the great input. Hopefully I can tackle this sometime this week, I'll let you all know how it turns out

 

[305HemiGuy]

So I finally got this clicking issue solved. After adding a second shim to the rear diff I still heard the clicking, so I replaced it with a new gearbox and diff assembly. Took it out to test it with the new rear gearbox and STILL heard the freakin clicking At this point I knew it had to be the front diff, because my center diff & rear diff were all new. Luckily I ordered two completely new gearbox assemblies when I was still focusing on the rear. So I open up the front gearbox and I find that a couple of teeth were worn down on the ring gear. I figured this had to be the cause of the click. So I took the new diff out of the other new gearbox and placed it in the bulkhead. Took it out for a spin, and voila, no more clicking! Below you can see the worn down teeth on the front diff. On the bright side, at least I have 3 new diffs in the rig now

 

[parcou]

So I finally got this clicking issue solved. After adding a second shim to the rear diff I still heard the clicking, so I replaced it with a new gearbox and diff assembly. Took it out to test it with the new rear gearbox and STILL heard the freakin clicking At this point I knew it had to be the front diff, because my center diff & rear diff were all new. Luckily I ordered two completely new gearbox assemblies when I was still focusing on the rear. So I open up the front gearbox and I find that a couple of teeth were worn down on the ring gear. I figured this had to be the cause of the click. So I took the new diff out of the other new gearbox and placed it in the bulkhead. Took it out for a spin, and voila, no more clicking! Below you can see the worn down teeth on the front diff. On the bright side, at least I have 3 new diffs in the rig now

View attachment 292923

Good work on the fix...

Why shimming is so essential and not only the diff by adding the shims to the ring gear...but also check how well it meshes to the input gear inside the gearbox as in the video I posted.

What I also heard that happens with new rigs is the mesh could be good but after some runs and it wears in we should recheck after a few runs...when the rig is new then you can space those out after breaking...

Bash on!!

 

[305HemiGuy]

Good work on the fix...

Why shimming is so essential and not only the diff by adding the shims to the ring gear...but also check how well it meshes to the input gear inside the gearbox as in the video I posted.

What I also heard that happens with new rigs is the mesh could be good but after some runs and it wears in we should recheck after a few runs...when the rig is new then you can space those out after breaking...

Bash on!!

Totally agree, I definitely plan on opening the gearboxes back up after a couple of runs just to re-check the mesh. Thanks for all your help, I appreciate it!