Talion Diff install with a shim help

[palmryde]

I am looking for assistance/tips as to how to successfully intall the diff with a shim without bending/ruining the shim.
I have not been very successsful, thus reaching out .

 

[gotnitro]

You shouldn’t bend anything installing a shim. They go between the diff case and the diff housing in the bearing race. If you are bending them, you might not need them.

 

[palmryde]

You shouldn’t bend anything installing a shim. They go between the diff case and the diff housing in the bearing race. If you are bending them, you might not need them.

Good point about possibly not needing them, nothing is holding it in the bearing race. So slightest resistance/misalignment while installing causes them to become damaged. I was thinking maybe gluing it to the race when you know you need it installed?

 

[trunkmonkey1]

This is a quick video, but is this what you see when you put yours together? Also, I'm pretty sure you shouldn't glue it in there. If you have no lateral movement when the diff is back in the housing, then you don't need shims.

 

[palmryde]

Thank you for your reponse, I feel much better about when shimming is neeeded now. Guess I over thought the process.

 

[Dan B.]

I am looking for assistance/tips as to how to successfully intall the diff with a shim without bending/ruining the shim.
I have not been very successsful, thus reaching out .

If they are so tight that you can’t insert them without them bending then they are not needed.

Good point about possibly not needing them, nothing is holding it in the bearing race. So slightest resistance/misalignment while installing causes them to become damaged. I was thinking maybe gluing it to the race when you know you need it installed?

No, don’t glue them. Ever. Dry fit the diff and check the play between the pinion and crown gear. All diff housings have different tolerances. Sometimes you need a couple of shims, sometimes you need none. The gear interface needs to be small, but not tight. Like the center motor pinion to spur clearance, but to a somewhat lesser tolerance.

 

[RC Steve]

When I can't get the shims to lie flat I use a small screwdriver to press them against the bearing for that last few mm of installation. This seems to work most of the time.

 

[Dan B.]

This is a quick video, but is this what you see when you put yours together? Also, I'm pretty sure you shouldn't glue it in there. If you have no lateral movement when the diff is back in the housing, then you don't need shims.

That video explains the process well, but I believe he actually did a terrible job of considering the pinion/crown mesh. It was clearly too tight. When mine are done they turn much more smoothly than that. His sounded “crunchy” and looked way more difficult to rotate. The gears definitely seemed to be binding a bit, and he didn’t spin a full rotation.
If you have a bulkhead that requires that many shims it’s actually easier to get proper gear lash. Instead of putting all four shims on the crown side and jamming the crown gear tightly into the pinion he should have put one or two on the right side until he got proper mesh. It would still probably have required four shims, but it would have been setup much better, been much smoother, and not as prone to heat or impact failure. I’m wondering if he is one of the guys that went to aluminum bulkheads because he was melting the case around the input bearings? It also looked like he put a rusty bearing back in there on the right. IDK, maybe I’m overthinking this as well…

 

[Hector_Fisher]

If they are so tight that you can’t insert them without them bending then they are not needed.

^ This

Dry fit the diff with no shims. Does it move side to side once installed? Do the gears roll well with no shims? If no to either, take the diff out, add shims, and try again. It's a process of experimentation -- trial and error. Once the diff rolls smooth and there is the smallest amount of play between the gears (at all points around the gears) then you're good.

 

[Schlepprock250]

And to add, even if they feel tight you still may need a shim. Getting in the last bit takes some easy finess. I use a pick set/small scribe to get the shim seated.

 

[KevinC]

I am looking for assistance/tips as to how to successfully intall the diff with a shim without bending/ruining the shim.
I have not been very successsful, thus reaching out .

I feel your pain because I’ve bent a few myself while shimming. In particular, when putting the gearbox cover back on…..that’s when I tend to bend them.

Before putting the diff back in the gearbox, add a tiny bit of grease to either the shim or the outside of the bearing to get the shim to stick in place and stay put. This has helped me.

cheers,
kev

 

[Fireteam-User]

Shimming the input pinion coul still be needed though.
Even if you have no side to side play the teeth could be still making contact on just the tips, this will also break teeth, but you can not feel it as the lash is minimal.

I have had instances where I shimmed the input pinion inwards, and then having to shim the diff itself towards the left (so adding a shim on the RIGHT)
Always check for as much tooth on tooth contact as possible.
Thats why I usually remove the bulkhead from the chassis, that way I can look into the housing from below, and ensure the pinion and diff gear have as much contact as possible.

 

[KevinC]

Shimming the input pinion coul still be needed though.
Even if you have no side to side play the teeth could be still making contact on just the tips, this will also break teeth, but you can not feel it as the lash is minimal.

I have had instances where I shimmed the input pinion inwards, and then having to shim the diff itself towards the left (so adding a shim on the RIGHT)
Always check for as much tooth on tooth contact as possible.
Thats why I usually remove the bulkhead from the chassis, that way I can look into the housing from below, and ensure the pinion and diff gear have as much contact as possible.

Great point. The only way to truly see that input gear mesh is to remove the gearbox and look underneath.

 

[palmryde]

Good ideas and inputs. I think I will put this on my over the winter diff disassembly/assembly/shim when it's all torn down.