Slight Clunk In Rear End From Dead Stop

[Renny]

I have been noticing a slight clunk from the rear-end when I start from dead stop at a light or stop sign. The rear end also produced a weird slipping feeling the other day when I was making a U turn from a dead stop. I attributed that to the locking rear end but I have never felt it do that before and in light of the clunk I am wondering if it is a symptom of something else.

I am running a volant CAI and a Edge Evo. I run the Evo in economy all the time. I am wondering if those two upgrades could could result in a blown rear-end. Since I installed the Evo, I have noticed that it drops agressively into a lower gear when your lay into the throttle. Could that have snapped a cog off the rear end?

I have a 07 yukon with a 5.3L Engine with 3.73 gears.

 

[Thundergod]

If these rear diff are that weak...it would really bum me out. Get it checked out while under warrenty.

 

[turboedmsp]

i have this clunking noise you speak of but my hoe doesn't sag when accellerating. not sure what the clunk is but mine is real faint noise.

 

[smoothfrc]

These rears are built to tow, so unless it is defective, you did not do any damage.

These are still leaf in the rear, so i am wondering if you are getting leaf smack (not sure what the technical term is).. Basically when you come to a stop or unload the rear, the leaf springs might seperate a little (i believe there is a little helper spring or something on the top fo the pile) and when you accelerate, the top leaf kind snap's back down on top of the rest giving you a noise.

I had this problem with my sierra and they threw a rubber bushing that slid around the top leaf and the noise went away. (looked like a really think rubber band)

 

[S.V.T.]

i get a clunking almost like the rear diff is locking and unlocking, or my rear tires are slipping a tad -- ONLY when i'm in AWD or 4hi. only when just the rear diff is engaged there's no issues.

 

[Gambler]

There was a TSB at one point for the transmission not shifting to first gear when it should, so when you started out it would realize it was in the wrong gear then switch to first causing a clunking noise. Not sure if this is what you are seeing, but you could ask the dealer to update you.

 

[sgmstr]

I had the same problem. It had this clunking noise when I start. Try lubricating the rear chasis and spring with WD-40. Mine went away after that surprisingly.

As to the other problem, it may be the transmission slipping. It also may be the transfer case issue lacking differential fluid or losing its viscosity. Check w/ your dealer if you are still under warranty.

By the way, is transfer case considered a component in power train warranty?

 

[SAUDILTZTAHOE]

These rears are built to tow, so unless it is defective, you did not do any damage.

These are still leaf in the rear, so i am wondering if you are getting leaf smack (not sure what the technical term is).. Basically when you come to a stop or unload the rear, the leaf springs might seperate a little (i believe there is a little helper spring or something on the top fo the pile) and when you accelerate, the top leaf kind snap's back down on top of the rest giving you a noise.

I had this problem with my sierra and they threw a rubber bushing that slid around the top leaf and the noise went away. (looked like a really think rubber band)

These trucks don't have leaf springs, they have coil springs.

 

[smoothfrc]

Huh, I never looked under the truck. I thought the rear was leaf, but your right, it is coil's.

 

[chevyrider]

I had the same problem. It had this clunking noise when I start. Try lubricating the rear chasis and spring with WD-40. Mine went away after that surprisingly.

As to the other problem, it may be the transmission slipping. It also may be the transfer case issue lacking differential fluid or losing its viscosity. Check w/ your dealer if you are still under warranty.

By the way, is transfer case considered a component in power train warranty?

Never use WD-40 as a lubricant. WD-40 actually dissolves and removes existing oils and grease on components resulting in premature wear.

 

[88eagle]

I had this "clunk" in my 4wd tahoe also ... go to GM dealer and get the "autotrax" lube, go home, drain the transfer case, replace drain plug, take out fill plug, put autotrax lube in (with a piece of vacc hose attached to be able to get the stuff in the fill hole and get some on both arms and driveway) until you are at proper fill level and replace plug. Drive tahoe around block a time or two and it should go away ...

I did this a year ago (after a bunch of the other tricks - lube on the driveshaft splines, special grease on the pinion shaft splines, etc) to mine and it was the easiest thing to do and low and behold it fixed it !!! I read this fix somewhere else on the web and a couple of GM mechanics I know told me there was no way that was gonna fix it - that I hadnt done the special spline lubes right or I needed a nickel driveshaft yoke !!!!

 

[coolrodskee]

check your Universal joints. They may need to be replaced with some that have a grease fittings so you can maintain lubrication on them

 

[Black Dog]

I know this is old but I wanted to chime in:
1. The leaf condition smoothfrc was talking about is probably called axle wrap.
2. The clunking in 4wd for S.V.T makes me wonder if you've got it in 4 on dry pavement; can cause binding which might unwind by chirping a tire.
3. Yes, transfer case is definitely part of the drivetrain for warranty purposes.
4. First thing I would suspect to the OP is U-joints, then the trans problem some have had before, then the rear gears but that wouldn't slip without biting or something like that.
5. I second don't use WD-40 on anything that is better greased.
6. Transfer case doesn't take differential fluid (gear oil), it takes ATF or a similar specific formula.

That's it.