Chewing up DIFFS??!!!

[nate_TalionKraton34]

Ok fellas, I knew my Talion had a grinding coming from the front but it wasn’t binding so I went for a construction bash yesterday and sent the s.o.b. Anyway.
Got home this evening and tore it down and this is what I found. As you can see in the picture the Metal bearing retainer that actually holds the ball bearings in game out and my ring and pinion chewed it up. I’ve had this truck for a year and this is the 2nd time I had this type of bearing failure in a diff, the other time was on the rear diff but it didn’t destroy the ring and pinion.

I’ve been seeing a lot of guys post they keep chewing up diffs and if this is occurring and your not noticing it could be the culprit. I will say I have bashed on this truck plenty so it’s not a reoccurring issue, however I do run the stock recommended diff oils and just deal with it diffing out in the front. My rear has been fine with no more issues since I replaced the bearing and that was over 10 runs ago. I ordered a set of fast Eddie sealed bearings and a GPM HEAVY DUTY RING AND PINION SET, Figured it was worth a try.

 

[revosmash]

Look like a fair amount of dirt was in the case. To stop the dirt from enter the case, try a thin layer of gear grease around all the case openings.

 

[PowerDubs]

'I do run the stock recommended diff oils and just deal with it diffing out in the front. '

My thought is why have the front spin any faster than needed? Friction is friction, so to me anything to lessen heat and wear is a good thing.

 

[RC DUDE81]

WOW! I've never had that happen. I'd clean your diff case really good and inspect for any cracks. You shouldn't have that much dirt inside your case. A little dust is okay but whenever I had that much, I had a busted case and didn't know it. I'd definitely use sealed bearings on the input and larger inner. Really keeps things clean and should keep that from happening. You also might want to put a thicker oil in the front. Over time it will melt everything down. The Arrma stock fluid is a basis then people can set them up for their liking. Not really meant to run hard in stock form IMHO. Also do you run a second shim on the outer bearing to tighten up the crown gear? Good luck bro! ?

 

[bicketybam]

This is how some people think the diffs are weak when in reality it's either the bearings or the diff case.

 

[nate_TalionKraton34]

Ok, thanks revosmash for the recommendation on the grease. I’m going To use the grease for the diff case in the picture posted below, I’m a heavy equipment tech by trade and that is what I keep on my service truck, figured it should be more than sufficient for the diff case.

I noticed when I went to take the screws out of the diff front cover plate the top ones were lose and I just started back in rc so honestly I didn’t do a full sweep and tighten things up before the run so that is my fault.

Rc dude 81, I watch you on YouTube, you are awesome bro, and to answer your question I do not run a second shim, but I will install one this time around.

What about diff oils? Center , front and back? I’ve been running stock because a friend of mine put stiffer diff oils in and swears it’s the reason he keeps chewing up pinions, but then again he keeps his punch on 8 and has a 1480kv motor. Thanks for the help guys

 

[nate_TalionKraton34]

Look like a fair amount of dirt was in the case. To stop the dirt from enter the case, try a thin layer of gear grease around all the case openings.

Thanks brother

 

[bicketybam]

Ok, thanks revosmash for the recommendation on the grease. I’m going To use the grease for the diff case in the picture posted below, I’m a heavy equipment tech by trade and that is what I keep on my service truck, figured it should be more than sufficient for the diff case.

I noticed when I went to take the screws out of the diff front cover plate the top ones were lose and I just started back in rc so honestly I didn’t do a full sweep and tighten things up before the run so that is my fault.

Rc dude 81, I watch you on YouTube, you are awesome bro, and to answer your question I do not run a second shim, but I will install one this time around.

What about diff oils? Center , front and back? I’ve been running stock because a friend of mine put stiffer diff oils in and swears it’s the reason he keeps chewing up pinions, but then again he keeps his punch on 8 and has a 1480kv motor. Thanks for the help guys

Start with 200k-300k in the center. I run 500k in all my 6s trucks.

 

[Jimbobjr]

I always though putting some rtv on the diff case before putting it tight to the chassis would help the dirt issue but never had. I do think the diff ring and pinion are a little wimpy especially running big tires on the Kraton. I have chewed up the ring on a couple but never had the bearing come apart. Bicketybam has good advice. Do double check you diff case for cracks around the mounting spots of the tower and brace support. Things could be flexing in there.

 

[nate_TalionKraton34]

Start with 200k-300k in the center. I run 500k in all my 6s trucks.

Ok, thanks, I have 100k and 500k. You think 500k in the center and 100k front and back would be too much?

 

[bicketybam]

Ok, thanks, I have 100k and 500k. You think 500k in the center and 100k front and back would be too much?

I think that would be ok. I usually run less than 100k in the front but as long as you can turn ok it should be fine

 

[nate_TalionKraton34]

I always though putting some rtv on the diff case before putting it tight to the chassis would help the dirt issue but never had. I do think the diff ring and pinion are a little wimpy especially running big tires on the Kraton. I have chewed up the ring on a couple but never had the bearing come apart. Bicketybam has good advice. Do double check you diff case for cracks around the mounting spots of the tower and brace support. Things could be flexing in there.

RTV is a great idea, thanks

 

[nate_TalionKraton34]

I think that would be ok. I usually run less than 100k in the front but as long as you can turn ok it should be fine

Ok, thanks, it’s all I have right now so I’m gonna give it a shot

 

[RC DUDE81]

I like to run 50k front, 500k center and 30k rear. An extra shim on the bearing front\rear for a better crown and input gear mesh and it makes a killer setup! ?

 

[RC DUDE81]

Ok, thanks revosmash for the recommendation on the grease. I’m going To use the grease for the diff case in the picture posted below, I’m a heavy equipment tech by trade and that is what I keep on my service truck, figured it should be more than sufficient for the diff case.

I noticed when I went to take the screws out of the diff front cover plate the top ones were lose and I just started back in rc so honestly I didn’t do a full sweep and tighten things up before the run so that is my fault.

Rc dude 81, I watch you on YouTube, you are awesome bro, and to answer your question I do not run a second shim, but I will install one this time around.

What about diff oils? Center , front and back? I’ve been running stock because a friend of mine put stiffer diff oils in and swears it’s the reason he keeps chewing up pinions, but then again he keeps his punch on 8 and has a 1480kv motor. Thanks for the help guys

I like to run 50k front, 500k center and 30k rear. An extra shim on the bearing front\rear for a better crown and input gear mesh and it makes a killer setup! ?

 

[DoNoHarm]

Your diff fluid setup is probably what kills your rear bearing.

Arrma provides their trucks with super thin center diff fluid. It’s useful because when you hit the gas, instead of having the rear tires bite into the terrain and push the car forward, it’ll diff out to the front wheels. It puts very little torque on the drivetrain and helps it last a long time.

When you put high weight into the center, now the rear tires will really dig in and force the car forward. It’s definitely more pleasant to drive like this off-road, but it puts a ton of stress and torque on the diff gears. This torque motion will wear out that bearing pretty quick, resulting in a stripped ring gear if not found quick enough. Arrma diffs are just barely adequate for the job (due to their size) and because of that, they have issues as soon as you try to put in thicker center diff fluid then 200k.

Hope this makes sense.

 

[Pfaulk54271]

I just spent about $180 on 1x HR diff (all 4 p/n's), ANOTHER complete diff from JRC and mugen outdrives. I'm really hoping this will be nice and tough. Anyone running ceramic bearings in theirs?

 

[DoNoHarm]

I do not but that wouldn't be a stupid idea. I'd put some ceramic bearings in there.

 

[Pfaulk54271]

Just trying to build the best diff possible, starting with one and if all goes well I'll end up doing them all like that.

 

[bicketybam]

Your diff fluid setup is probably what kills your rear bearing.

Arrma provides their trucks with super thin center diff fluid. It’s useful because when you hit the gas, instead of having the rear tires bite into the terrain and push the car forward, it’ll diff out to the front wheels. It puts very little torque on the drivetrain and helps it last a long time.

When you put high weight into the center, now the rear tires will really dig in and force the car forward. It’s definitely more pleasant to drive like this off-road, but it puts a ton of stress and torque on the diff gears. This torque motion will wear out that bearing pretty quick, resulting in a stripped ring gear if not found quick enough. Arrma diffs are just barely adequate for the job (due to their size) and because of that, they have issues as soon as you try to put in thicker center diff fluid then 200k.

Hope this makes sense.

This is 100% bullcrap. I run 500k in all my Arrma rigs with no problems. So do countless others. Do not listen to this guy.