Notorious Front diff main input gear

[blakeaowen15]

I herd clicking front my front diff when I brake, I have parts on the way to fix it. For shimming the diff, is the little input main gear in the front diff suppose to move back and forward at all? Like should I be able to push on the small pinion and it move forward/backwards. Obviously not talking abt rotating bc Ik it’s suppose to do that.

 

[slick2500]

I herd clicking front my front diff when I brake, I have parts on the way to fix it. For shimming the diff, is the little input main gear in the front diff suppose to move back and forward at all? Like should I be able to push on the small pinion and it move forward/backwards. Obviously not talking abt rotating bc Ik it’s suppose to do that.

No it shouldn't move in or out. Make sure you replace both the crown and the pinion gear as a set do not replace just one or the other or you will just strip them again.

 

[hobo]

no take the grub screw out of the cup and push back so there's no movement there

 

[blakeaowen15]

No it shouldn't move in or out. Make sure you replace both the crown and the pinion gear as a set do not replace just one or the other or you will just strip them again.

Replace both of these included in the picture?

 

[slick2500]

Replace both of these included in the picture?View attachment 269259View attachment 269260

Yes sir.

 

[hobo]

check your outer small bearing could be on its way out

 

[blakeaowen15]

Yes sir.

I appreciate it, I’m trying to find a video that’s just replacing the big gear that the small pinion spins, have any videos or know how to do it. I don’t want to take out any fluid but will add some. Just want to replace the big gear.

check your outer small bearing could be on its way out

How do I tell if the small outter bearing for the small pinion is dunzo?

 

[SrC]

The only and best way to install the Input cup to the input gear is to open and remove the Diff from the Bulkhead, use your finger to push the input gear towards the diff input cup. There should be no slack. Yet the gear should still spin smoothly.
There is no way to do this from the outside on an assembled diff/ bulkhead. It will always show some slop. NG for the Gears.
Most imprtantly use Shims at the Main gear side. You can easilly fit in 2 shims, if you are patient enough. Most of my diffs consistently end up using 2 shims. I rarely have issues with my RTR diffs.
But I always toss the internal Satellite/Sun gear shims out the box when new., and ONLY use Mugen Seiki shims. My diffs are fairly durable now. Just normal wear. They never explode anymore. I can easily get 20+ packs out of my diffs, before service and using clean Fresh Oil.

check your outer small bearing could be on its way out

+1
That outer input cup BB is so small for its application. They get sloppy and this will cause gear chatter / gear slippage also.
Good point. A BB that is often neglected. Overlooked.

 

[blakeaowen15]

The only and best way to install the Input cup to the input gear is to open and remove the Diff from the Bulkhead, use your finger to push the input gear towards the diff input cup. There should be no slack. Yet the gear should still spin smoothly.
Ther eis no way to do this form the outside on an assembled diff/ bulkhead. It will always show some slop. NG for the Gears.
Most imprtantly use Shims at the MAin gear side. You can easilly fit in 2 shims, if you are patient enough. Most of my diffs consistently end up using 2 shims. I rarey have issues with my RTR diffs.
But I always toss the internal Satellite/Sun gear shims out the box when new., and ONLY use Mugen Seiki shims. My diffs are fairly durable now. Just normal wear. They never explode anymore. I can easily get 20+ packs out of my diffs, before service and using clean Oil.

+1
That outer input cup BB is so small for its application. They get sloppy and this will cause gear chatter / gear slippage also.
Good point. A BB that is often neglected. Overlooked.

I’m new to this rc stuff, what for you mean by getting 20+ packs out of your diff. And I’ve tried and tried to find the right shims for my car and ordered them and they weren’t right. Would anyone be able to help me find the shims I need to shim my diff? I have a notorious 6S BLX V4!?

 

[slick2500]

The only and best way to install the Input cup to the input gear is to open and remove the Diff from the Bulkhead, use your finger to push the input gear towards the diff input cup. There should be no slack. Yet the gear should still spin smoothly.
There is no way to do this from the outside on an assembled diff/ bulkhead. It will always show some slop. NG for the Gears.
Most imprtantly use Shims at the Main gear side. You can easilly fit in 2 shims, if you are patient enough. Most of my diffs consistently end up using 2 shims. I rarely have issues with my RTR diffs.
But I always toss the internal Satellite/Sun gear shims out the box when new., and ONLY use Mugen Seiki shims. My diffs are fairly durable now. Just normal wear. They never explode anymore. I can easily get 20+ packs out of my diffs, before service and using clean Fresh Oil.

+1
That outer input cup BB is so small for its application. They get sloppy and this will cause gear chatter / gear slippage also.
Good point. A BB that is often neglected. Overlooked.

Mugen 0206 is the part number for those shims just to clarify.

 

[hobo]

I appreciate it, I’m trying to find a video that’s just replacing the big gear that the small pinion spins, have any videos or know how to do it. I don’t want to take out any fluid but will add some. Just want to replace the big gear.

How do I tell if the small outter bearing for the small pinion is dunzo?

a lot of movement on the inside race

 

[Hector_Fisher]

If you have the time, i'd just replace the bearings. They are a pain to get to, might as well replace the bearings when you replace the gears.

Save yourself some time later down the road.

 

[SrC]

New gears and new BB's best replaced together. Or you will ruin a new gear set rather fast. Been there. New Gear sets don't come cheap. BB's do.

 

[slick2500]

Isn't there a sticky in the 6s section for shimming the diffs?

-edit- I lied it was in the chassis and drivetrain section. https://www.arrmaforum.com/threads/how-to-shim-your-arrma-diff.5396/