what would cause a clunk when you let off the gas...

[natorious]

so my car has no rattle or clunks or anything except one... when you let off the gas it clunk but only then not over bumps or anything

oh and it only does it when i let off the gas all the way if i let of slowly it doesnt do it... i think it does it when the tranny shifts when braking too

so its like vrrroooooooom-clunk-vrooooooooom-clunk

btw its a slushbox

[rwh11385]

if you let off the gas quickly and there's a clunk you feel, it is most likely the guibo aka flex-disc

you should have that replaced.

same thing on my car, costs about $30-40 dollars. (the part that is)

[nando]

might be motor mounts too. or subframe/trailing arm bushings. there's a bunch of things you should check.

[backlife]

nope, that would most likely be your u-joints when the flexdisk is going out it causes a rattle-clank-thunk under your shifter when you accelerate


-adam

[325eowner]

i bet it's your differential, mine does the same thing. my mechanic said it's from play inside it. gonna be replacing mine in the not too distant future.

[Bryson]

might be motor mounts too. or subframe/trailing arm bushings. there's a bunch of things you should check.

this is definitely the loudest, most heavy of them all.. could be the diff and/or diff bushing also. A broken center carrier and fucked up flexdisc can make jumps, as can tranny and motor mounts (motor mounts displacing the drivetrain)
turn on your AC, the clunk will get much more predominant at freeway speeds, try on/off gas a few times until you can locate the general area of the thunk, then get back to us.
If he's lowered/drives hard, I'm betting subframe/t-arm bushings

[E30godz]

mine does this very badly too...and my engine mounts and tranny mounts are totally fucked...i plan on replacing them shortly

[natorious]

i am gonna try and find where its comming from on my way to work today...

i'll get back to you in a bit....

but as of now i definatley think its something in the back

more info:
car is bone stock
was NEVER driven hard until the last week (already had the clunk)
but was driven on new york/new jersey roads meaning not exactly the smoothest.. think surface of the moon

[darien28]

is it like a hard clunk that you can feel and seems to come from the rear and under your car? i had the same problem... changed tranny mounts, guibo, center support bearing... and it all went away.

[PeterCip]

Check the status of your diff bushing before anything else. while under accel your dif torques up against the car, only to fall back down with a clunk when you let off the gas. ask me how I know...

[bwanac]

That is the problem I have, worn diff bushing. Really need to fix it, but I can handle it for a little while longer!

[natorious]

i am thinkinking its the bushin on mine as well but i havent gotten under there yet to get a closer look