Have a 90 RX-7 GXL N/A that makes a single "light" clunk or thumping noise when the car first starts moving and when it finally comes to a complete stop. I thought it would be the front rear diff. mount, so I lowered the rear end and replaced it, even though the old one was not split. Put it all back together good and tight and the noise is still there. Any ideas or suggestions??

 

this is EXACTY what is happening to me. i repaced mine and the thumping is still there. the only thing i can think of is that there is slack in the REAR diff mounts. i remember that when put the diff back onto the rear posts there was about a quarter inch gap between the bushings pressed into the alluminum and the ruber on the lower cups that bolt over the posts. everything was tourqued to spec, but the gap was still there and it settled back down once i took the jack off (but could presumably ride up and cause the clunking during acceleration).

\any thoughts or incite would be very helpfull.

also, in another thread i heard someone say it could be the diff itself, but how would i check this? as far as i can tell its ok and there didnt seem to be excesive slack when i rotated the axels/drive shaft to reposition everything.

 

i had that small gap between where the rear diff mounts bolt in as well. could this be the cause of a small clunk?

 

i had a clunk in the rear on accell and going over some bumps, solved it by replacing the camber links... the two o-o shaped links

might want to give that a try

 

Usually a clunk when engaging gears means play in the drive shaft- I'm sure I'll be corrected if wrong.

 

I get the same thing when I shift...both into gear and out.

 

If certain dif and tranny mounts are sound, ya gotta think U joints. Wisdom is a clunk in lower gears is the front joint and higher gears the rear.. clunk in both.. the obvious.

You might not get much if any play simply streesing the drive shaft by hand. I U joints could still be the problem. Had that same happen to me.

 

I agree that it would probably be U joints if not that your diff gears are probably worn, perhaps thicker gear oil will work for a temp fix.

 

so you guys think it might be the drive shaft? or is that the u joints on the 1/2 shafts?

 

drive shaft

 

Thanks for all the feedback. I'll get under it this weekend and check out the camber links and the U-Joints on the drive shaft. If I'm successful, I'll post my findings.