Clunking noise

[PaViper]

Had mine out today for a short ride. I developed a new sound though. When I sart out from a dead stop, I get a bit of a clunk from the rear of the car. My wife says she can feel it as well as hear it. Any ideas....it doesn't do it except when you start out.

 

[Mike_W]

Is it when you just begin to take off, and the clutch begins to grab? And then from behind you in the center somewhat you hear a "clunk"?

If it is, then I don't know what it is.

Mike

 

[PaViper]

Thats exactly what it is....I thought you had the answer for me for a second there.

 

[GraphiteGTS]

Throwout bearing?
Universal joint?
Try taking off in second gear and see if you hear the same sound. If you do, it's probably not the tranny. If you don't, it perhaps is related to first gear or a synchro.
Lubed your universals lately?

 

[Vic]

I had a clunk from the rear, when putting torque on the wheels. (As when you let the clutch out)

Dealer tech did the following
1. Tightened all nuts and bolts under the car
2. Changed rear axle
3. Checked dozens of things, including half shaft U-joints, driveshaft, shaft splines, frame rails, motor mounts, steering rack, blah blah blah, etc etc

None of the above did anything to fix the problem. Then they started telling me it was just body noise, and lots of cars also do the same thing, and its probably nothing, etc. Since they couldn't find it, they tried to tell me they all do it, and even cited examples of other customer's cars that do the same thing, only worse.

At this point, I was thinking about invoking California's Lemon Law, but I had to give them every opportunity to try and fix it, before they give up, which they didn't, to their credit.

The last thing they tried fixed the issue!!! Yaaa!

They changed the right rear wheel hub. Seems the soft aluminum alloy hub gets peened out by the steel outer race of the wheel bearing. As it gets worse, the wheel bearing starts to shift around in the carrier, especially during the initial application of torque.

Anyway, its gone now, and I'm a happy camper again...

 

[GraphiteGTS]

Vic,
Did your clunking sound come all at once or was it progressive?

 

[Vic]

It got progressively worse over time.

 

[GraphiteGTS]

PaViper, did your noise get progressively worse? (Most noises do.) You write as though it came all at once.

 

[viper spray]

Sounds like half shafts to me.

 

[safireviper]

I also had a "clunking noise" in the rear of my car. It turned out my car simply needed " friction reducer " in the rear differential. The noise went away immediately.

 

[Mike_W]

Thats exactly what it is....I thought you had the answer for me for a second there.

Nah sorry. My car does it when I put it into reverse sometimes.

Mike

 

[PaViper]

Thanks for all the responses, it will give me something to check before I get to the dealer and start tap dancing with them. It seems to have started all at once especially since my wife noticed at the same time I did.
Thanks again for all the ideas.

 

[PaViper]

I had a clunk from the rear, when putting torque on the wheels. (As when you let the clutch out)

Dealer tech did the following
1. Tightened all nuts and bolts under the car
2. Changed rear axle
3. Checked dozens of things, including half shaft U-joints, driveshaft, shaft splines, frame rails, motor mounts, steering rack, blah blah blah, etc etc

None of the above did anything to fix the problem. Then they started telling me it was just body noise, and lots of cars also do the same thing, and its probably nothing, etc. Since they couldn't find it, they tried to tell me they all do it, and even cited examples of other customer's cars that do the same thing, only worse.

At this point, I was thinking about invoking California's Lemon Law, but I had to give them every opportunity to try and fix it, before they give up, which they didn't, to their credit.

The last thing they tried fixed the issue!!! Yaaa!

They changed the right rear wheel hub. Seems the soft aluminum alloy hub gets peened out by the steel outer race of the wheel bearing. As it gets worse, the wheel bearing starts to shift around in the carrier, especially during the initial application of torque.

Anyway, its gone now, and I'm a happy camper again...

How many miles were on the car when you noticed this. Just curious since I have about 1500 miles on mine. Thanks

 

[Vic]

About 17,000.

 

[gotV10]

just wanted to say thanks to PaViper, i have had my viper to several techs here in fl. no one could find the "clunk". one tech even told me that i need to buy a new rear chunk. well after reading this post last night, i have my biddy, a mechanic at the Chevrolet dealership where i work tighten my rear hubs...NO MORE NOISE!!!!! AGAIN THANKS SO MUCH....it just ***** having the guys at work giving me $hit about a viper, but in reality they know where it rates to those vettes. (side note) my roomate and i both sell at the same chevy store, and both drive vipers, they love it there..lol
ryan

 

[sbkim]

I just noticed similar noise. Mine happens right driving in 1st after backing up the car. It's fairly loud and it seems to be coming from the passenger side... Any ideas???

 

[SF Final 286]

My car was making a seriously loud clunking at the rear end too. I could actually feel it! It occured in 1st gear... I would be starting a from a roll and then when I jabbed the go pedal and released it (ie. make the car lunge forward), I would hear and feel the clunk. I went for a ride with the Viper tech and showed him. He later diagnosed that the rear differential was broken. I didn't get the details of what was the exact problem. He replaced the entire rear end and fixed the problem.
Thanks to Stevens Creek Dodge.

 

[CrimsonVenom]

I also am having the same problem with a clunk. I just had the car in to be inspected and, after tightening all bolts as PaViper had tightened, they recommended changing the rear. They did not replace the wheel hub (as I suggested) but only tightened the bolts. The thing is, the noise did decrease quite a bit; do you think they need to over-tighten/replace the hubs (as previously stated) because they were very specific about only "tightening to specs"? My problem with the clunk only occurs on initial application of torque when turning left or right at a 75-90 degree angle (usually when pulling out slowly) and not when accelerating in a straight line. The car also started doing this at about 17,000 miles. I would hate to spend thousands on a "fishing" expedition (rear end, shocks, steering) when it appears that might not fix the problem. How difficult would it be to change the wheel hub? I've replaced the battery and changed the tires myself. Any help would be appreciated.

 

[sbkim]

bump - i think I have similar issues as CrimsonVenom. I went out and tightened differential mount bolts - one was loose. Torqued to 100ft/lbs. Not sure if that solved the clunk though...

 

[Bonkers]

Can anyone explain what to look for when seeking loose hubs? I mean if I were to crawl under my car tonight and do a visual inspection would I be able to see/feel the problem?

 

[CrimsonVenom]

Well, quick question. How much do you think I'll be looking at for a new/rebuilt rear differential (installed)? I need to do some comparison (dealer)shopping. I did some independent verification on the clunk. We had the car jacked up in the back with it out of gear and the parking brake off (don't try this at home) and in turning the wheel hub, you could actually hear the clunk noise from the rear, as well as see at least a quarter inch give between the drive shaft and the differential... which should obviously have none or very little. Both half-shafts were tight, and all of the balljoints, etc. looked good. Any prices out there?