Help "LOUD" clunk....

[SoCal Rebell]

Help \"LOUD\" clunk....

I was at Willow Springs this weekend road racing when I hear a very loud clunk coming from my rear. It seemed most pronounced when I accelerate and let off then "clunk". I've hear this before to a lesser degree and chalked it up to "a little play" in the driveline, but now it's BAD. I went under the car to check, rear wheels on firm, all u-joint bolts on half shafts & drive shaft tight but I did notice my drive shaft would turn an inch in each direction before the rear wheels turn. I have after market gears (3.54) installed by a reputable Viper tech. Any ideas?

 

[Leonard Knight]

Re: Help \"LOUD\" clunk....

SoCal, you might check your trans mount or motor mounts as well. Also there are some VERY small bolts at the end of the half shafts at the end opposite the final drive. I have been told that these can loosen up during track events as they get hot and the locking material can break down. These are very small, I think about a 5/16" head on them.

Leonard

 

[Roland L-Ocala FL]

Re: Help \"LOUD\" clunk....

Ron,
I think this is "normal" for the Viper. As it heats up, and you will heat it up more if you are racing it than if you were just driving it on the street, the play becomes more noticeable. I noticed this more on longer trips where the heat soaks into everything more. Was it still clunking as loudly after you got off the track and drove it on the street, or after it had a chance to cool down? I got a note from Bob Woodhouse about this some time ago. Another thing to look for is the ladderbar bolts at the rear. See if the ladderbar is sliding by checking the bolts, if it is sliding, you will see a "track" where the ladderbar is moving under the bolts, maybe a quarter inch long.
There was a recall for this sometime back on the Gen I's, all the bolts on the suspension had to be retorqued to a higher spec. Not saying this is the case here, but something you might want to check anyway.

Another thing to check is the amount of lubricant in the rear end, make sure it is full and that it is the correct part number for the lubricant (synthetic, I think).

 

[pj]

Re: Help \"LOUD\" clunk....

Eadch of my Viper did this - some times louder than others. First couple of times scared the crap out of me, because it was usually under hard acceleration; I thought I had broken something.

Posted here and learned that it isnt uncommon; couple of things worth checking, but nothing really to worry about.

 

[SapphireGTS]

Re: Help \"LOUD\" clunk....

Mine did it off the dealers lot with 9 miles on it. I shrugged and looked at my friend. He made the smart a$$ comment, "It is a dodge ya know"

But it does sound like something broken. Mine does under accelleration usually when the car is being turned to the right

good luck.

 

[WCKDVPR]

Re: Help \"LOUD\" clunk....

SoCal,

Mine did the exact same thing as you described.

Found the diff mounting bolts to be loose. Really loose! Tightened them up and the clunk was gone.

Good Luck.

 

[Tom Welch]

Re: Help \"LOUD\" clunk....

Ron,

You should not have 1" of play in your driveshaft. Sounds like something with the pinion or ring gear bearings...........

Tom
Http://btrviper.com

 

[Vip-RT10]

Re: Help \"LOUD\" clunk....

What you describe is actually a loose torsion stabilizer bar. This bar has 2 bolts that need tightening.It did the same to me, only in hard accel. Lift the car and torque them down properly and the problem is solved. Let me know what the result is.

 

[Ulysses]

Re: Help \"LOUD\" clunk....

Definitely check the tranny and diff mounting bolts.