Typhon Rear diff full of dirt

[JDowns]

Looks to me like the bearings got hot and sunk into the plastic, then the diff ground that groove into the plastic housing.

This doesn't look stock to me.

 

[Wmorgan]

I just rebuilt my Typhon rear diff last night as part of maintenance and found a bit of sand and gravel bits ? in the housing. Nothing i could build a sand castle like yours, but a surprising amount. recently rebuilt kraton and noto which i run in same area and they only had grease and a little metal dust as expected. Dirt may get in easier due to the narrower wheels kicking more dirt at higher energy and the lower profile (just a theory on my part).On Typhon i Replaced pinion gear, but input gear was same as a new one I had just in case.
Looking at your pinion pics it's toast. Those teeth are very warn. Hard to tell from pic and when it's in place, for me at least, that input may be good like mine was. If you have a new one to compare it to would be helpful until you get an eye for it.

 

[Primarrma]

What surface have you been driving on? It almost looks like cement in your gearbox case? If it was sand you'd see the particles, this is like powder.

 

[slick2500]

Looks to me like the bearings got hot and sunk into the plastic, then the diff ground that groove into the plastic housing.

This doesn't look stock to me.

View attachment 43296

That's actually the chassis that has that mark on it. That is pretty common with this platform especially if you jump a lot.

 

[CL-Audio]

Did you crack open that diff to see what was inside? I'm thinking there will be a diamond or some poop with all that charcoal you got in there!

 

[Lazy Bushman]

I have no futher advice to add than what has been stated so far, though another option is to consider the Tekjo gaskets as well but I use grease like @Primarrma. I would like to congratulate you on the amount of dirt you collected, that is very impressive

 

[MrQQ]

Buy a new complete gearbox from Jenny's and check the front one too. Those old gears are toast. Then seal every join with grease, it will work fine, and try to service your car more often.

i never used grease for sealing the diff. doesn't that atract a lof of dust? I usually try to keep my kraton as cleaner as possible... if i'd see a chink of dirt around the diff cups i would start crying... lol

also i'll definetely buy those tekjo gaskets!

 

[Primarrma]

i never used grease for sealing the diff. doesn't that atract a lof of dust? I usually try to keep my kraton as cleaner as possible... if i'd see a chink of dirt around the diff cups i would start crying... lol

also i'll definetely buy those tekjo gaskets!

Grease to seal the case, the gaskets only seal between the chassis and the bottom of the gearbox, nothing to stop dust getting in via the joins in the case or around the bearings. It's up to you, whatever works best in your situation.

 

[MrQQ]

Grease to seal the case, the gaskets only seal between the chassis and the bottom of the gearbox, nothing to stop dust getting in via the joins in the case or around the bearings. It's up to you, whatever works best in your situation.

don't your joints trap lots of dirt?

 

[bicketybam]

The amount of dirt in there suggests a broken gearbox. Grease or no grease, gasket or no gasket, there should never be that much dirt in there.

 

[slick2500]

The amount of dirt in there suggests a broken gearbox. Grease or no grease, gasket or no gasket, there should never be that much dirt in there.

You would be surprised how much of that dirt came in through the metal shielded bearings. I had maybe half of that in one of my Outcast rear gearbox cases after my first teardown. I stuck a new diff in with some rubber sealed bearings and didn't get any more dirt in the same gearbox.

 

[Primarrma]

don't your joints trap lots of dirt?

Better trapped on the outside than inside, yes it seems to attract dirt, but a quick brush with a toothbrush and it's gone.

This is what happens to a an untreated gearbox when driving on sand, this was a brand new factory assembled Talion rear diff that I was servicing after 10 runs or so. The bad bearing didn't help. The top image is of the serviced diff ready to go back together.

 

[chevys10zr2003]

Better trapped on the outside than inside, yes it seems to attract dirt, but a quick brush with a toothbrush and it's gone.

This is what happens to a an untreated gearbox when driving on sand, this was a brand new factory assembled Talion rear diff that I was servicing after 10 runs or so. The bad bearing didn't help. The top image is of the serviced diff ready to go back together. View attachment 43394View attachment 43395View attachment 43396View attachment 43397View attachment 43399View attachment 43400

That's a lot of grease! I just put enough on to coat all of the teeth and that's it.

 

[Primarrma]

That's a lot of grease! I just put enough on to coat all of the teeth and that's it.

Yeah it's a lot, on a race kit I don't use that much, but when the diff spins up it mostly flies off, the extra picks up any dust that might get in. I don't see it causing any issues? My other thought is that when the car gets jumped around some of it might fall back on the teeth at some point regreasing itself.

 

[chevys10zr2003]

Yeah it's a lot, on a race kit I don't use that much, but when the diff spins up it mostly flies off, the extra picks up any dust that might get in. I don't see it causing any issues?

I guess it should in theory seal the diff housing from letting stuff past in the first place. So crap can't get to the diff if it can't make it past the grease. I'm guessing that is the red and tacky grease which does stay put pretty well.

 

[Primarrma]

I guess it should in theory seal the diff housing from letting stuff past in the first place. So crap can't get to the diff if it can't make it past the grease. I'm guessing that is the red and tacky grease which does stay put pretty well.

It's quite thin, but tacky it does seem to help, next time I pull my diffs down I'll take some photo's, but last check I did after doing this, the diffs were perfect, no dust at all and if a bearing was to go or the case crack it will contain the issue. It is overkill, but grease is cheap, gearboxes are expensive.

 

[MrQQ]

Better trapped on the outside than inside, yes it seems to attract dirt, but a quick brush with a toothbrush and it's gone.

This is what happens to a an untreated gearbox when driving on sand, this was a brand new factory assembled Talion rear diff that I was servicing after 10 runs or so. The bad bearing didn't help. The top image is of the serviced diff ready to go back together. View attachment 43394View attachment 43395View attachment 43396View attachment 43397View attachment 43399View attachment 43400

What grease is in there?

 

[Primarrma]

What grease is in there?

https://www.inoxmx.com/products/mx8-extreme-pressure-grease/

But any will do really.

 

[MrQQ]

https://www.inoxmx.com/products/mx8-extreme-pressure-grease/

But any will do really.

I use some white grease from hobbyking. I apply enough to cover all the teeths. I really don't know if it's good lub or not... Also I don't if I should put a generous amount or just enough to cover gears.
I also have white grease in a spray bottle... I bought them for bearings but it's very liquid and never used it really...
Its liquid white grease proper for bearings... But maybe not rc bearings... ???

 

[Primarrma]

I use some white grease from hobbyking. I apply enough to cover all the teeths. I really don't know if it's good lub or not... Also I don't if I should put a generous amount or just enough to cover gears.
I also have white grease in a spray bottle... I bought them for bearings but it's very liquid and never used it really...
Its liquid white grease proper for bearings... But maybe not rc bearings... ???

You are doing the right thing, I just fill my diff cases on my Arrma cars, because I drive on the beach. You don't need very much normally. On my race kits I don't fill the cases like this. The white grease will be great for sealing the case too.