If you have followed my last few posts about a shudder/vibration in the rear end, you know what im talking about. Well, for a while the vibration was only when coasting/decellerating (sp?), then all the sudden, the noise went away. Apparently, that was the calm before the storm...On my way to work this morning, the noise came back in a different form. Now it sounds like the rear end it going to shatter into a million pieces at around 50mph in 5th or 6th gear on a light acceleration. Just the most god awful vibration/whirring sound you'd ever want to hear coming from your rear end.

When I finally limped it to work, I crawled under to see if anything looked or felt out of place. The ujoint on the rear shaft felt fine, wasnt hot or excessively sloppy, but what I did feel was on the side of the pumpkin where the driveshaft enters, the casing around the pinion was fairly warm, warmer than the cover side of the pumpkin. Both mechanics here at work seem to think one of the pinion bearings is out.

The big question is, is the rear end covered under powertrain warranty? I was hoping it was going to be the u-joint, very cheap and simple part to change. Anyone have any other ideas? Any tests I can do to pinpoint it? Im so fed up with this truck...

 

I would suggest changing the U-joints, a friend had a similar probably when decelerating, drove him nuts. turned out to be simple joints which are fairly low cost and quick to change. Eliminate those then see if the probably goes away.

SAS

 

I thought was the u-joint as well, but when I pulled into work after an hour drive, the rear of the pumpkin where the drive shaft goes in was pretty warm. Also, the u-joint had no play from what I could see.

 

just because a ujoint has no play does NOT mean its good. They loose their grease, then dry up, get hot and start grinding away the needles inside. Thats when they get loose.

Its a Very good chance Your u joint(s) are on their way out. Its normal for the rear end to get warm

 

when my joints went it had no play but would vibrate and pop on throttle lift. I finally found it was the joints by having my dad get in the truck and go through the gears foward and rev moving a foot or so. I then saw the slack in the joints. It was funny because I could not get the joints to move at all by grabbing the shaft and push and pulling.

 

Im really hoping and praying that it is something just as simply as a u-joint. I knew it was normal for the front of the pumpkin to get warm (where the cover and fill plug is), but I didnt think it was normal for it to get "more than slightly warm" on the shaft side of the pumpkin only a few inches in from where the driveshaft attaches.

 

is there play in the pinion bearing at all?

 

I couldnt feel and up and down or side to side play. Only a small amount of rotational play, hence the pinion shaft feels tight in the housing.

 

If the joint is bad I which I hope, then the heat it produced would heat the front of the housing up a lot. Mine got very warm on the rear of the drive shaft and the front of the housing.

 

Back to your orignal question about warranty.Is not the factory warranty on a 06 only 3/36? 05 powertrain was 7/70 but 06 I thought was changed to 3/36.Now if you bought a EXTENDED SERVICE CONTRACT differant story.Probaby is.If not and your over 3/36 I'd get me some NEW fliud and and bottle of anti chatter/shudder and pull cover and do a look see.If nothing seen add new fliud and the bottle of anti chatter.To further checkyou may need to drop the driveshaft and rotate the joints as they seize on these trucks and don't get loose until the very last. So how many miles on the truck? How long since differantial been service?

 

IM at 40K as of now, The rear and front diff fluid was changed to Amsoil severe gear at 25 or 28K, cant remember off top my head. Im really hoping its just a u-joint...if that is the case, its easy to fix. If it is the pinion bearings, then, well, thats just sad for a truck with only 40K on the clock and IMHO the dealer should warranty the repair regardless since the part likely started failing before my warranty was up. Not to mention the fact that major parts such as rear end bearings should no way on gods green earth be failing at such low miles, but should probably outlast almost every other drivetrain part on the truck.

 

I think I'd put the back end up on stands and run it in the gears and try to find the noise. Like already said, u-joints and the carrier brg don't have to feel loose to be bad or grinding up inside. You can pop the axles and drop the driveshaft from the pinion and put an in/lb wrench on the pinion. You should have about 20 in/lbs rolling tq. if the preloads are still good. Check the magnetic plug on the diff cover for metal. That should show if you have anything very bad going on. Craig

 

Thanks for the info. truck is actually at the dealer now, they'll look at it tomorrow. Funny thing is, on the way to the dealer, the noise wasnt there anymore...im not sure if it is something that is affected by how warm the drivetrain is or what. If they cant find anything I'll try the jackstand idea and take the shaft of the pinion and check the in/lbs. I did check the plug, it was pretty clean, only a minimal amount of fine powdery metal.