Thump, thud sound from rear - only at take off, even low speeds.

[boosteddirty]

Mine is doing the same. It started clunking after a couple of burnouts. Hopefully its not the yoke thats messed up.

[graphikg]

So I am still having the issue. Coming down to it - I think it is the U-joint.

[graphikg]

HMMMMMMM --- got an update for you all.

I lifted the car with a jack from the passenger side rear and heard a noise similar to what was going on. I checked the diff bolts and they were pretty tight already. So far, I havent had the issue since. WEIRD! I guess something just wasnt seated right.

[EREKSHUN]

i had the same issues and found that my Guibo was trashed after replacing it and still having the issue i had to replace my drive shaft due to bad U-Joints.

[graphikg]

Ill double check that.

[Ian Bowers]

Is your differential installed securely to your subframe? I've had the bolts loosen slightly, and it caused a "clunk" in first gear.

[graphikg]

Did some more investigating. It is definitely not the exhaust. I am getting kinda stumped.

It only happens at take off, even within the 5 MPH range. It does not happen during higher speeds even when punching on and off the throttle at higher speeds.

It could be my Polyurethane subframe bushings. OR... it could be something in the driveline behind the CSB. I checked the CSB and everything there looks fine.

[graphikg]

Dropped the exhaust and the CSB looks okay. It looks as new as when I installed it about 10 months ago. As I also said, the subframe and trailing arm bushings are also polyurethane new.

I am starting to think it is the exhaust banging back there. I think this because 1) it only happens going forward and I dont hear the "thump" going in reverse, and 2) the noise only started happening when I improperly dropped my car from the jack stands. I think one of the stands slanted when lowering the car and pushed on the exhaust which is why there was a hole created on the exhaust and it came off one of the rubber hangers.

I think the thumping is the exhaust. I cant find any other culprit.

[jlevie]

Ok. I lifted the rear of the car and spun the wheels. Even with shifts and movement of Te d-shaft, it has no noise. That's what's making think it is the subframe bushings. Something may have shifted when improperly dropping the car from stands. Plus, the problem doesn't get worse at higher speeds.

Take a look at the rubber mount of the center support bearing. If it has tears in it you have likely found the cause of the noise. Bad u-joints and a failed center support bearing, at least initially, won't make noise when the rear wheels are in the air and spinning as very little torque is being applied to the drive shaft.

That said, there could be other problems in the rear suspension. By this time the rear trailing arm bushings, subframe bushings, and differential mount are way overdue for replacement just from age. And check to make sure that the bolts that mount the differential are tight.

[graphikg]

Ok. I lifted the rear of the car and spun the wheels. Even with shifts and movement of Te d-shaft, it has no noise. That's what's making think it is the subframe bushings. Something may have shifted when improperly dropping the car from stands. Plus, the problem doesn't get worse at higher speeds.

[graphikg]

Ok - so this problem definitely happened when the car was completely lifted on four stands and I took it off improperly. DARN! I heard a loud sound that that is what it was.

How long can I drive on it like this? Long enough for me to get the part in?

[motomaster99]

I was thinking subframe bushings. CSB is possible as well.

[defaultName]

Glad I read this because my car's has the same symptoms. I'll have to check it out in the spring...

[StereoInstaller1]

I had exactly the same issue, mine was ancient subframe bushings. Even though yours are new, you shoulkd take a close look at them, make sure they are well-seated.

If anything, you need to look at the CSB and the diff mount, right?

GL!
Luke

[jlevie]

It however only happens at take off. If I am coasting at speeds higher than 25mph I dont hear it - Even if I punch it in the powerband of a gear.

If the earliest stages, the noise from the drive shaft will only be evident in first or reverse when proceeding from a stop. When greatest torque is on the drive shaft. But it will get worse.

Get the car up in the air and take a look at the rubber mount of the center support bearing. If torn the drive shaft is the problem.