just_curious

Looks like there is play in the ring and pinion setup that I dont remember being there when I did it. Some say this is typical on a mechanical locker or lunch box style but I just dont think its this much.

Drained and filled rear end back in October, coming up on 70k miles now since the 4.56s and truetrac were installed.

First video is cycling from drive to reverse while holding brake and towards the end I let off brake a little and that's why it actually rolled some.

https://i.imgur.com/BsWhclY.mp4



Second video is obviously disconnected drive shaft which cut a ton of play out but still not as it should be. Pinion nut is still tight and no front to rear play like a bad bearing (nor was there debris from bearings in the oil best I could tell). Checked U bolts, good. Checked leafs, no cracks. Pattern looked good back in October as well no abnormal wear signs.

https://i.imgur.com/nSYxp3W.mp4



Next steps:

• Due to what looks like potential seeping I suppose I need to get a new seal and do that. I keep a check on it and haven't had any noticeable loss, ever. But rather make sure this doesnt have the chance to run dry.
• Get marking compound and run the pattern to check that
• I have no clue what else to check short of pulling the carrier out and seeing if something is up with the pinion and or go through the whole setup process again.

Does anyone have any ideas?

Also don't know that it matters, don't think it does, but driveshaft/trans side had no rotational play while in park. I should've checked it in N with parking brake maybe? Or is that not going to tell me anything?

Sometimes at lower speeds I get a clunk when taking off, maybe this is the truetrac doing its thing and maybe it has gotten sloppy? can it, because again don't remember this after initial setup? Best way I can describe it is that its like a short hesitation and then clunk and and accelerates like normal.. this can be replicated easily at 20-30mph or giving her 80% throttle from 50 or 60 mph. This is the first vehicle I have had something like this in and If it was the carrier It shouldn't do that at higher speeds right? I am certain I can make it do it even rolling 80 then WOT.

strutaeng

Pop the differential cover and inspect the fluid/magnet would be my first step. While you are there, measure backlash with a dial indicator. Report the value.

I don't really know anything about the True Trac. Is that a Thorsen style locker?

Maybe worth removing the axles and inspecting the splines that engage into the carrier?

What axle is that BTW?

The driveshaft should have minimal play since the little parking pawl engages into the notches of the output drum in Park. That sounds normal to me. In neutral the driveshaft it should actually rotate.

just_curious

@strutaeng I did that back in october nothing abnormal from all that you can see and wear pattern looked fine, here is a picture from then. I didnt think to check the pattern and backlash when I did this but I should have.




Yes the trutrac is what is called a torsen style diff. It is helical gears inside that provide the limited slip action as opposed to clutches.

This is on a 10b rear axle on a silverado 1500

Sort of seems like everything is points to pulling it apart the more I search around and think about it. On an offroad group I am in half the people say its normal for this style and then the other half say something is majorly wrong. Go figure

strutaeng

Was the carrier replaced when you did that work? If so, everything has to set-up like from scratch: pinion preload, carrier preload and backlash.

just_curious

No did the 4.56s and trutrac back in fall of 2020 setup preload backlash and all that then. Back in october of 2021 I just pulled the cover and did a fluid drain and replace and checked pattern while it was off.

strutaeng

Ok, that makes sense now...

RB04Av

How much preload did you put on the carrier bearings?

strutaeng

Um...

Well, since the locker is a Thorsen and doesn't have clutches to wear, the fluid should be pretty clean with little material in it...drop the cover and inspect fluid?

If there was too little carrier preload: the carrier bearings would chatter and create noise...No noise or howling from the rear end?

If there was too much carrier preload: the carrier bearings would overheat, burn up and it would be obvious...? overheated, burnt smell in fluid?

Ditto for the pinion bearings.

Just brainstorming for OP here. 🤔

RB04Av

It's near impossible to get "too much" carrier preload. THIMK: exactly HOW would you even do that?

Too little on the other hand, means that after a few miles, the carrier sloshes from side to side within the housing depending on what's going on at the moment. Which sounds like what he has in progress here.

I like to set em up with at least .010" (.005" too much shim on each side), and as much as .020" if I can get it. I can't imagine ever putting in "too much". .020" is tough enough as it is.

strutaeng

You are absolutely right. I guess in my mind I was thinking like the 10.5" 14 bolt with those little rotating adjusters, but that doesn't apply here. Disclaimer: I've never opened or messed with a 10 bolt. 🙈

I did regear a newer "12 bolt" 9.5" axle (out of the truck) last year, which was my first regear job. ☺️ I kept the G80 carrier and made myself a homemade redneck "case spreader". Even then, the original carrier shims had to be tapped in firmly. Not sure what is the proper way to do that? Probably impossible to insert thicker shims than came out? That's not here nor there...😞

I think you are on to something about the carrier moving around though... maybe it kinda "floating?" for lack of a better word?