tech Q : hard thunk in rear of car...

[illreaxion]

been trying to diagnose this...upon starting the car, under hard acceleration and shift into another gear (mostly 1 to 2) if I dump the clutch suddenly theres a clunk or thud thats coming from the back...I was wondering if it was my driveshaft/u joint...I wont be able to tell til this weekend when I can hopefully get my car on a rack and take a better look.any help/input would be much appreciated.

[bcar240]

is it just after you start the car, or anytime? I have a very similar, if not the exact same, problem. I am not really sure what it is, so I can't really help that much, but if I had the time to look for the problem I would start with what you mentioned, and maybe the differential, possibly where the driveshaft inputs into it. To me it sounds like there is some freeplay in something and it is flapping around a little bit, but it is strange that it goes away after the car warms up.

[Ubernoober]

More likely to be a subframe bushing or a suspension arm bushing. A U-Joint that bad would vibrate like mad and a differential that would clunk like that would also tend to howl at highway speeds.

[illreaxion]

no howling on the highway at all...no vibration at all either...Ill check the bushings and see where to go from there. thanks guys.

[masticatingcow]

I get the same clunking noise when I gas it under 1800 RPMs in 3rd, 4th, or 5th gear. In the coming weeks I'll be under there checking everything out (I'm finally installing my exhaust) so if I find anything you should look for, or hell, if you find anything I should look for, post up! First one to find the noise wins! LOL. Good luck man.

[illreaxion]

^^

sounds good man...good luck to you too.

[my91silvia]

I've seen some 240's come into my shop with the rear subframe bushings completely wasted so thats whats i'd be looking for, I can ask some master tech's if you'd likehope it helps

[VitaminT]

I have the same type of problem but also have a whine from the rear diff. I am hoping that my new unit (profesionally setup) will correct the issue. I also have subframe spacers

[Bryants95240sx]

Subframe spacers had the same problem yours are probably gone so either get the spacers or the solid mounts from spl.

[illreaxion]

^^how much do those run for...?

[masticatingcow]

I checked out my subframe, and yeah, the bushings are toast. I'll be replacing them with aluminum mounts from SPL in a few weeks. Cost = $159. Worth it to me!

[illreaxion]

^^

lol, judging from your sig w/ 227 k on the clock, I would assume so. where can one purchase a set of those?

[masticatingcow]

How about http://www.splparts.com?

They have a bunch of other goodies for the older-than-the-average-S13 suspension. Good stuff. Enjoy.

[wanna240now]

good luck with those alluminum mounts.

Your going to hear EVERY bump/rattle/vibration in road and drivetrain. SOme don't care, but just thought i'd warn ya.

Also, post up how the install goes. You have to drop the entire subframe, so i wanna hear how it goes.

[masticatingcow]

Oh yeah, I know it'll be louder. I've never owned a nice, quiet car, so it really won't be a problem.

I think someone else already posted up in the installation... but I'll be sure to add my .02.