when I let off the gas at most spoeeds i get a clunk. also when I hammer it from a stop or out it in gera theres a thump too, but I dont know if theyre related. I pretty sure the shifting in gear clunk is the u joints , but I"m not sure on that either.
thanks,


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Derek Johsnon
90 red rs 3.1 Mods--hypertech thermomaster chip, 160 degree thermostat, and K&N filter
Soon coming: compucam 3020, 1.52 rocker arms, 3.73 posi, and msd 6a
I Live my life a quarter mile at a time(the fast in the furious), only it takes me like 18 seconds to do it in this v6!!!

 

Your right, it's just the drive shaft slack tighting up, I get that some times when I'm in over drive and i let off the gas then push it back down again.

 

Check your transmission mount

 

Sounds like the tranny mount. Also, this is post 1000 for me!!!!! I have broken a barrier.

 

A shameless 1000'th post plug? How funny. j/k. Mine was better. I had an entire post dedicated to it.

 

i dunno, when my mount went i didn't hear it from the rear. i heard it during hard shifts and it sounded like it was coming right out from under the shirter...or even more up front the the passenger side floor pan. but you can check it anyway. i also for a whole heard a clunk coming from the rear of my car when i would go over pot holes or bumps. then my dad and i found it when we were rotating my tires. if you remove the back tire and looke behind the the drum there is this thing that looks like and elongated bolt with rubber stoppers on it. well, mine rusted out and snapped loosing the stoppers and creating a thump when the axle would move. dunno if this is it, but it was a cheap fix..like 3.00...and its easy to look for. there is a diagram of it in the chiltons manual too, i can look up the name of the part tonight...

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1990 Firebird 3.1
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- Auto Trans, TA Body Kit
- Home Made C.A.I.
- ASP Underdrive Pulleys
- MSD 8.5mm Superconducter Wires (custom-cut)
- MSD GM Blaster Coil
- AC Delco Cap & Rotor
- Bosh Platinum +4 plugs
- Mobil 1 Synthetic Fluids
- 2.5" Hooker Aero-Chamber Cat-back
- 2.5" Hooker Elite Stainless Extension Tips
- GTS Blackouts (stickers removed)
- TB Bypass

KILLS = Dodge Daytona (stick), 2000 Toyota 4 Runner 4WD,
1997ish Ford Explorer, "older" Jeep Cherokee (don't ask why they are all SUVs...who the hell knows?)

LOSSES = 300zx (had him half way through 2nd, he was manual)

"The racing dice added 5hp...I SWEAR!"

 

Mine is doing the same thing....I thought it was coming from the rear...but it is my tranny mount...check there first.

 

Mine did that too. It turned out to be the engine mount, when I would give it gas th torque would lift the engine from one side then in would drop back down, and make a thumb near the center console. It also F***ed up my tranny.