Kraton Learning stuff

[arrma6snewbie]

After getting my esc problem figured out set my punch up to 9 thing straight rips. I shimmed my diffs on the ring gear side and boom everything good. Took it out on the street to do some speed pulls and started skipping. Thought that sucks so I would just ease into the power. Today it finally gave out. Blew my rear diff gears. Bought another new rear diff shimmed it again and checked the gear mesh all seemed good. Took it in the street again and it starts to skip again. Turned down the punch and everything stopped. Where are people getting the shims on the pinion for the diffs. The shim for the big bearing inside the housing to push the pinion further into the ring gear.

 

[Camaroboy383]

After getting my esc problem figured out set my punch up to 9 thing straight rips. I shimmed my diffs on the ring gear side and boom everything good. Took it out on the street to do some speed pulls and started skipping. Thought that sucks so I would just ease into the power. Today it finally gave out. Blew my rear diff gears. Bought another new rear diff shimmed it again and checked the gear mesh all seemed good. Took it in the street again and it starts to skip again. Turned down the punch and everything stopped. Where are people getting the shims on the pinion for the diffs. The shim for the big bearing inside the housing to push the pinion further into the ring gear.

You can shim behind the bearing or behind the heel of the pinion.. if your dead set on behind the bearing just look up the measurement on the exploded view..

so if its 15mm o.d you want a shim that is 15mm x 13mm x .1 or .2

Behind the pinion heel would be 10mm x 8mm...

I usually use the latter as that's what I have on hand..

Just search ebay for which ever size shims..?

As a side note, are you pre loading the cup against the bearing? Or just sliding it on and tightening the set screw?

 

[arrma6snewbie]

You can shim behind the bearing or behind the heel of the pinion.. if your dead set on behind the bearing just look up the measurement on the exploded view..

so if its 15mm o.d you want a shim that is 15mm x 13mm x .1 or .2

Behind the pinion heel would be 10mm x 8mm...

I usually use the latter as that's what I have on hand..

Just search ebay for which ever size shims..?

As a side note, are you pre loading the cup against the bearing? Or just sliding it on and tightening the set screw?

Prodding? All I have been doing is shimming the left side bearing on the outside to push the ring closer to the pinion.

Prodding? All I have been doing is shimming the left side bearing on the outside to push the ring closer to the pinion.

I meant to say preloading

 

[Camaroboy383]

Prodding? All I have been doing is shimming the left side bearing on the outside to push the ring closer to the pinion.

I meant to say preloading

Pinion bearing pre load is a very important part of the diff building process.. ball bearings naturally have slop from inner/outer race groove to the balls them selves... if they were tight they would heat and seize quickly..

install your pinion into the bearings, install the cup onto the pinion input shaft..

Now take your thumb and pointer finger and press the cup and pinion together against the bearings inner races, then tighten the grub screw.. this will pre load the bearing races onto the balls removing the natural slop.. do not squeeze.. just pinch.. this inherently takes the yield out of the pinion, which is most often the culprit of failure..

If you keep an eye on this every 6 packs or so your diffs should last a very long time.. unless you end up snapping pins, which will be the next failure point..?

 

[arrma6snewbie]

Well poop. I was wondering about the pinion moving back and fourth. Take that sucker back apart

 

[Camaroboy383]

Well poop. I was wondering about the pinion moving back and fourth. Take that sucker back apart

????... yes, if you can grab the cup and wiggle it the preload is gone.. this is a good method of checking for bearing wear / yield as well... a simple check can save you on some gear sets..?

Also the ring gear carrier shimming should be done after the preload setup, as that can directly relate to shims needed for correct mesh..

I tend to setup my mesh for "0" lash.. the diff should still turn smoothly though, there is a fine line between "0" lash and to tight so pay close attention to the feel of the rotation..

The reason I set for 0 lash is due to pinion bearing yield, after a couple packs they WILL start to yeild, creating larger mesh lash, which typically puts you right in the ballpark for perfect mesh..?

Also make sure to clean the threads of the cup and screw, use loctite on the grub screw of the input cup and let it dry for 24hrs before use

 

[arrma6snewbie]

????... yes, if you can grab the cup and wiggle it the preload is gone.. this is a good method of checking for bearing wear / yield as well... a simple check can save you on some gear sets..?

Also the ring gear carrier shimming should be done after the preload setup, as that can directly relate to shims needed for correct mesh..

I tend to setup my mesh for "0" lash.. the diff should still turn smoothly though, there is a fine line between "0" lash and to tight so pay close attention to the feel of the rotation..

The reason I set for 0 lash is due to pinion bearing yield, after a couple packs they WILL start to yeild, creating larger mesh lash, which typically puts you right in the ballpark for perfect mesh..?

Also make sure to clean the threads of the cup and screw, use loctite on the grub screw of the input cup and let it dry for 24hrs before use

Now you say wiggle you mean in and out. I just installed all new bearings and those are tight but it does have in and out play.

 

[Camaroboy383]

Now you say wiggle you mean in and out. I just installed all new bearings and those are tight but it does have in and out play.

It should never move in and out.. that is way worse than wiggle / side to side / up and down.. and definitely instant death for gears..

 

[arrma6snewbie]

Cool. Lucky for me I’m not braking stuff I’m learning. So you don’t shim the big pinion bearing you just shim the ring gear after the preload is set

 

[Camaroboy383]

You can still do both.. an added .1-.2 shim behind the pinion will definitely help for greater tooth contact heel to toe.. if you do decide to shim behind the pinion or pinion bearing be sure that's done first and preloaded before shimming the ring gear carrier bearings...

 

[arrma6snewbie]

Thanks man

 

[arrma6snewbie]

I feel like I should just buy the aluminum housings because of how often they are apart. I don’t want to end up stripping out the plastic. I think I’m going to have to shim the pinion there is a good gap between the diff case and the pinion. I quant pull out a feeler gauge because I did it in the truck. We will see what happens tomorrow when I rip it

 

[IrieWheeler]

Please disregard, can't delete

 

[Camaroboy383]

Diff cup has nothing to do with it.. the external carrier shims do not touch the diff cup.. your confusing internal and external shims..

 

[IrieWheeler]

Diff cup has nothing to do with it.. the external carrier shims do not touch the diff cup.. your confusing internal and external shims..

Of course, my mind was littering in the wrong thread, sorry guys. It'd be nice if there was an option to delete. Cheers