Rear End Problem w/ Pics

[V6 Beast]

My rear diff started making some noise so I pulled the cover and found bad Sh!t. The oil was a very lovely silver metalflake. I look on the bottom of the eaton unit and I can see it has been rubbing against something very hard.... see attched pics. Anyone have any idea what it could be contacting? I am a rear end idiot so not even sure how to take the thing apart to look.

www.caro.net/sully/temp/eaton.jpg
www.caro.net/sully/temp/eaton1.jpg


thanks in advance for any ideas

Sully

 

[blackplague]

If there are no marks in the cover

like something was rubbing between the carrier and the cover, i'd say maybe the pinion is loose rubbing the carrier. Remove the driveshaft, does the yoke move in and out? It shouldn't. What happens sometimes is the crush collar compresses and looses the preload on the bearings that the pinion rides on in the axle housing. When that happens, the pinion moves back and forth like a big hammer on the ring gear and possibly the carrier.

 

[V6 Beast]

ok dropped driveshaft and there seems to be no play front to back of the yoke. I can twist 1/4 inch or so but no front to back. I also can not see anyplace it is rubbing. THe front gear there looks brand new.

I noticed hte top of my pinion snupbber is pretty beat up ... could it be hitting something when I launch? Would a new snubber have any affect?

Sully

 

[buickboy]

Also, check out the wear pattern on the ring gear teeth. Maybe backlash or Pinion shim clearancing problem.

 

[Hawaiian Turbo]

Any marks on the pinion? If that mark wasn't on the unit when you installed it, that's the only thing it can come in contact with. When you say you have a bout 1/4 of backlash, see if the pinion rides towards the unit as you turn it.

HTH, Paul

 

[NCTURBOS]

Steve, what are you running for cntrl arms and pinion angle? Stock driveshaft? You need to put a dial indicator on the gear.

 

[cruzn57]

rear end

Just a couple ideas,
Just what noises were coming from the rear?
Check the carrier bearings, look for worn bearings, that would allow the carrier to move forward to contact the pinion.(not to likely)
Look around in the bottom of the diff, something had to be bouncing around to hit the carrier.
From your pics, can't see the pattern on the ring gear, (primarily the pull side) the pattern should be centered front-to back, and in the center of the tooth (each one should look the same)

You sure it wasn't on there when it was installed??(the marks)

good luck and post what you find, so we all can learn.

cruzn57

 

[Jeff Rand]

Is your magnet still in place on the differential cover? It might have come loose and is in the housing.
Jeff

 

[GNVAIR]

To be quite honest, those dont look like wear/rubbing marks. During the machining process of the carriers, the outside diameter of the case is turned down right around the openings.
I have several Eatons here that look just like that.
The brand new after market Eaton I just installed in the truck had the same marks.
If you have a rubbing noise, then I would look into the pinion bearings. Put an inch/pound torque wrench on the pinion nut and check the turning torque. Off the top of my head, it should be 15-20 in/lbs. If it is more than that and feels tight, then you most likely have a bearing that is starting to gall. That will cause a rubbing sound when moving.

 

[monte_383]

Won't the turning torque reading be more in this case (on account of friction) since the rest of the diff (carrier), axles and prolly tires and wheels are now attached. I usually check turning torque without the carrier installed, maybe I've been doing it wrong? -Chuck

 

[Benched]

Can you supply more information as to what the sounds were like and when they occured?

Also, here is a small trouble shooting guide.

http://www.differentials.com/techi.html

There is other useful information at this site.

 

[Intercooler]

Anyone see what I see? It looks like the cross-bolt for the pin is not there. Check it first. Seen here:

http://home.att.net/~jesse.adkins/eaton1.jpg

 

[gnsrule]

I dont think those are rubbing marks, possably from balanceing at the factory.
Take a pry bar and go against the carrier houseing and the bearing caps and try to move it right to left. It should not move. Grab the driveshaft and go up and down,in and out, shouldnt move there either.
Now go to the wheels, with it jacked up, put a prybar under the tire and try to lift up, it shouldnt move there either. They go in and out about 1/8 in tho so dont freak out when you see that.
Quite possably you have a bad outer axle bearing and axle tho. When the bearing goes out, it takes the axle w/ it. Very common. That would explain alot of silver.
Depending on how many miles and how silvery the oil was. if all you got was silver tint and NO chunks in the oil, its posably the bearing races starting to pit from contamination, which if cought early enuff, can be saved for a while.
If nothing moves around with the prybar, slap the cover back on,oil it up w/ a fresh shot of additive and take it for a spin. Hopefully that will at least buy you enuff time an inevidable differential rebuild. Which in your case, I would take it to a differiential rebuilder or a 4x4 shop, they do alot of diff work.

 

[V6 Beast]

I am going to take the whole setup apart tommorrow. It is making a Whining noise right now... not as bad since replacing the fluid bust still there.. When it's cold and you turn a corner slower it kinda chunks a bit kinda like it doesn't have posi additive. I will update over the weekend.

Sully

 

[Intercooler]

Originally posted by V6 Beast
I am going to take the whole setup apart tommorrow. It is making a Whining noise right now... not as bad since replacing the fluid bust still there.. When it's cold and you turn a corner slower it kinda chunks a bit kinda like it doesn't have posi additive. I will update over the weekend.

Sully

Did you look at the pic I put up showing the bolt missing?

 

[V6 Beast]

yes I did. I already had the cover back on by the time you posted so I couldn't go back out and look. Will check it out tomm for sure.
thanks


Sully

 

[V6 Beast]

Well took it apart today and the front Pinion Bearing was shot. So replaced all the bearings in the rear end and everything is working smooth now. As far as the missing bolt. There is a recessed area on either side of the carrier and the one in the pic did not contain the bolt. It was on the other side safe and sound.
I wonder if this could be responsible for my missing 4 mph.


Sully

 

[REEDOG]

Gene, explain why removing the cruch collar increases durability.

 

[REEDOG]

I just rebuilt my rear using the GM crush sleeve. Where do you buy the shims to replace the sleeve? Do you use the same method of measuring preload with the shims as you would with the crush sleeve? GM recommends 20-25 inch lbs with new bearings.