fire-chickens

Alrighty, I recently boguht a 1996 Formula Firebird. After about 2 weeks of owning it, i get a light clunking when letting off and re-applying throttle. Also I get an identical clunking when slowing down at a stopsign or redlight when it shifts down to a lower gear, I have the A4 trans. I'm thinking its the Universal joint but am not sure if it is exactly that or if it in fact is the U-joint, which end might be bad the front or the rear u-joint?

How much do Universal Joints cost and are they hard to replace?

jsteele90

iTrader: (13)

check your trans mount as well

fire-chickens

if this helps any I just remembered that it also clunks when going over some over bumps where the car goes up and comes back down, like a hump. not like a pothole.

eseibel67

iTrader: (10)

Could be suspension bushing, trans mount, u-joint.

Although I doubt your problem is a U-joint, they are easy to change. Torch the old nylon snap rings out, and install the new joints. Just make sure the joint pivots easily on both planes before you install the driveshaft.

fire-chickens

alrighty ill check out the universal joint and then the trans mount. I'm thinking its either one of the two because its a light clunk and it does it when giving it throttle and when its pops into a lower gear declererating, its not a thump, or a thud. and the reason i believe its a universal joint is that its towards the back more and wehn it goes over a hump and clunks it could be the reduced weight or somethign of the car and the stress comes off the driveshaft.

Spartan7

iTrader: (7)

It sounds exactly like a bad u-joint.

Crawl underneath and try pushing the driveshaft up and down, forward and back. It should make no noise and it shouldn't move. If it does, there you go.

fire-chickens

well the car only has 70k miles, which U-joint would most likely be the culprit for the clunk?
the rear u joint is what im thinking

Chris97z

I bought a 97 Z28 that started doing the same thing shortly after I got it. Light throttle let off and reapplying would make the clunk. When coming to a stop I can hear and feel a clunk almost every single time. I replaced my transmission mount and no change. I've decided its either the Ujoints in the driveshaft or my motor mounts are shot and its allowing my engine to move a lot which causes my exhaust to bang up against something under there.

DarkJuggalo

iTrader: (6)

my first clunking came from the trans mount, my seconds clunking was from my LCA bolt being sheared off. i would check these first

Crimsonnaire

iTrader: (1)

You get this clunk when letting off and reapplying throttle on smooth road? If so, exactly when does it clunk, during throttle adjustment only or during the whole acceleration/deceleration?

fire-chickens

i have since gotten rid of the car, or shall i say heap of crap..

Crimsonnaire

iTrader: (1)

Oh. I'm sorry to hear that. I'm not familiar with the LT1 F-bodies, but I can say the LS1 (98-02) counterparts are quite decent.

Will you be giving GM another try or switch over to Ford?