Diff's and Yoke's

[NSFW]

Hey peoples.

Last year I swapped my rear diff in my Silverado from a GM 10bolt semi floater to a GM 12 bolt semi floater with a factory locker within.

In an attempt to foresee problems, I estimated that I was going to get either one of three main problems, or all three depending. Yoke problems, Driveshaft problems, u-joint incompatibility issues. I also did some research to effectively solve the problems before I un-screwed a nut, or so I thought I did anyways.

Now its 16K km later, and I have a f&^%$ clunk from the rear end. It's obviously a backlash issue, but from WHAT? I was able to tighten the pinion nut when I inspected it last weekend, but just put some pucker-stink on it.. not crazy loose..

I changed the 12Bolt yoke over to the 10 bolt yoke so it would mate up with the driveshaft, obviously.

Other then the wider pocket spacing, the yokes were similar in height, and had the same spline dimensions, number and outside diameter as well as plunge depth.. SO I just took the 1330 off and slammed the 1310 on. Piece of cake.

Could there have been anything I missed that resulted in this clunk. Am I going to school here, is what I am asking. WHat did I miss?

(I did check the slip yoke position at full compression, and compensated with lifting blocks and leaf spring stack number)

I set it up for 15 - 17in lbs drag torque with a new seal and sealed the splines. Changed the diff oil, (80/90 is what the book told me) and added a new u-joint plus pinion seal to finish it all off cool beans.

My ONLY suspect that the backlash has appeared because a bearing in the diff has been compromised due to... aliens or...maybe age? The diff was swapped from a 99 I don't know why these things don't just pile up without reason.

Any additional info would be super helpfull right now. I got a 2500km road trip coming up in a week, and I need to know if I gotta blow this apart or risk it blowing itself apart somewhere along the highway. This weekend would be the weekend to do it.

[Mike GMC]

I swore I had the same issue with my stock 10 bolt. It seemed to have excessive backlash and was clunking. I opened up the diff and found an inoperative g80 locker and alot of slop in the side and spider gears. Ring and pinion backlash seemed ok for 215k miles. I was about to order $1000 worth of rebuild parts. I decided to change the u joints first even though I couldn't see any thing wrong with them. Turns out the joint at the t case slip yoke was in very bad condition. I couldn't tell until the shafts was out of the truck. I still have a bad g80, but my noises are gone. Still haven't rebuilt the diff.

[NSFW]

I swore I had the same issue with my stock 10 bolt. It seemed to have excessive backlash and was clunking. I opened up the diff and found an inoperative g80 locker and alot of slop in the side and spider gears. Ring and pinion backlash seemed ok for 215k miles. I was about to order $1000 worth of rebuild parts. I decided to change the u joints first even though I couldn't see any thing wrong with them. Turns out the joint at the t case slip yoke was in very bad condition. I couldn't tell until the shafts was out of the truck. I still have a bad g80, but my noises are gone. Still haven't rebuilt the diff.

Thanks for the advice Mike.

 

This is what happened. It's NOT the u-joints.

 

I ripped it apart this morning.. spider pin got the typical wear.. but I other then surface discoloration.. I cant find any ridges with my fingerail. clips..worn as ****. Those getting replaced.. The magnet had allot of that silvery crap on it... plus some chunks.. The Gov Lock system appears to be functioning. However due to the fact I have no frigging clue how to disassemble it without taking a sledge hammer to it.. for NOW I am going to assume its alright and set it aside..

 

The ring and pinion have a WIDE heel-toe contact patch on the gear teeth. 275K KM's later and I guess.. well I dont know.. Doesnt make noise.. Both on the drive side and the coast side and well worn.

 

I inspected all the bearings and races and I was not IMPRESSED at all. I am worn thru the hard-casing on all but 1 bearing. Theres also evidence of what looks like IMPACT damage on one of the bearing cages that carry the carrier. The outer axle bearings are also showing the same deal. UGH..

 

At this point I am looking at two ways to fix it.. Either an entire rebuild.. less the crown and pinion.. or if it needs a crown and pinion.. Im just gonna swap it out for a C14-FF and ditch this diff all together. I have to change u-bolts anyways right. Price dictates.. I can get a diff thats in way better shape for 300.00 so lets see where the parts land.

 

Pictures below.

 

PS Outer Axle Bearing. Hard Surface Wear.

 

Corrisponding Axle. Matchy-Matchy

 

DS Outer Axle Bearing Same deal.

 

Axle Same deal.

 

PS Carrier Bearing.. Surface Damage from eating metal...and what looks like IMPACT damage from.. my guess someone SLAMMING the axle shaft back in.. Idiots.

 

Bearing RACE.. not chucking pieces yet.. but worn out.

 

DS (ring side) Carrier Bearing. Same-same fuched.

 

DS Race.. yep.. almost thru the hard surface..

 

Pinion bearing Inner

 

Inner Race

 

Pinion Bearing Yoke Side

 

]

Corrisponding Race

 

 

 

I went ahead and smashed all the seals out. Off to get prices now..