Differential gear mesh (underdrive)

[summerof95]

Just installed a set of Axial underdrive gears, and it feels like there's an issue with the gear mesh.

I double checked the pinion bearings, because I know that's a common culprit, but the pinion seems properly seated.
It seems to be an issue with the differential or ring gear, but I'm not really sure what to look for there. Again, all the bearing seem properly seated.

Perhaps it's an issue (piece of grit) between the carrier and the ring gear?

Ideas?


EDIT:

So, I looked closer at the two ring gears, the stock and the UD, and I noticed that the center recess is more shallow on the UD. Instead of tightening against the carrier, the gear was actually tightening against the locker.
I assume this might be due to the lack of a gasket, part AX30385, which would typically be sandwiched between the carrier and the ring-gear when running a geared differential.

There's no point in running oil with the locker, so instead of the proper gasket, I cut out some card-stock, which I imagine is about the same thickness as the gasket would be.

*Poof*
Perfect mesh.

[Eric0424]

The gasket is in the kit instructions even with the lockers, although it's only .5mm thick (.020") you see it can be a problem when left out of the build.

[Tom95YJ]

I never needed the gaskets with my UD gears or OD gears in my axles mine meshed perfectly w/o them

[Eric0424]

Originally Posted by Tom95YJ

I never needed the gaskets with my UD gears or OD gears in my axles mine meshed perfectly w/o them

There's no guaranty one way or the other, just depends on how far out of spec the parts are. Most won't have a problem with or without the gasket, but occasionally a few will.

[TakeOffYouHoser]

Originally Posted by summerof95

Just installed a set of Axial underdrive gears, .....


*Poof*
Perfect mesh.

THANK YOU!

And now I have this set aside for when I install mine if there are any problems.

[summerof95]

So I thought: "Gee, this gasket seems pretty important to proper gear mesh. I wonder why this RTR didn't come with them installed."

Well, then I had a sudden "D'oh!" moment.



On the left is a gear with the gasket installed. On the right is a gear with the gasket removed.
Looks pretty darn similar, eh?

As it turns out, the stock and UD gears are not really machined to different measurements. Despite examining all the gears pretty closely, and washing them in hot soapy water, I COMPLETELY missed the fact that there's still a gasket stuck to one of them.

[Eric0424]

It doesn't help that the gasket is a same color as the gear. If you look close enough you can see it, but you already know it's there. It's a little easier to find.

Our gears aren't actually machined, they're either cast or MIM or some other molding/casting/forming process. Machining leaves behind telltale signs of being cut. A lot of small complex parts are MIM these days, like the lockers our ring and pinion gears, done right MIM parts can be as strong as some machined but at a fraction of the cost to make.

[GodSpeed999]

FTR the Axial HD beveled gears don't come with those posts to hold the gasket in place. No big deal. Just mentioning it. I still used the gasket when installing mine.

Axial Racing - Axial Heavy Duty Bevel Gear Set - 43T/13T

[Kylar]

this is some good info here, something you dont think about...

i have a set of gears that arent as smooth as i would like, going to give this a try. I bet the gasket is missing, or doubled up

Thanks!

[Eric0424]

Originally Posted by GodSpeed999

FTR the Axial HD beveled gears don't come with those posts to hold the gasket in place. No big deal. Just mentioning it. I still used the gasket when installing mine.

Axial Racing - Axial Heavy Duty Bevel Gear Set - 43T/13T

Those gears probably are machined, actual steel, spiral cut teeth, better/stronger/quieter gear mesh. Look a lot better than the stock kit and RtR gears.

I plan on upgrading to some of these, but I need to actually drive the Wraith and Dingo a while and see what breaks or wears out.

[Tom95YJ]

Originally Posted by Eric0424

Those gears probably are machined, actual steel, spiral cut teeth, better/stronger/quieter gear mesh. Look a lot better than the stock kit and RtR gears.

I plan on upgrading to some of these, but I need to actually drive the Wraith and Dingo a while and see what breaks or wears out.

Common parts to break on a dingo. Tranny gears, stock r&p wear then start popping. Driveshafts break. OD mated with UD are awesome in my dingo