Thumping from rear end - Please help!

[mole5430]

Okay, I hope one of you on here has come across this problem before! Anyway, I have an 87 fox body that was recently rebuilt and new lower control arms and spings were put on rear end, along with new springs on front end. The quad shocks were also removed during this time, and since that point I will hear and feel a strange thumping noise from rear end, though I cannot tell what side it is coming from. Torque boxes are fine, and nothing in rear end (took cover off) appears to be "off", though the noise still occurs. Noises WILL NOT occur during hard driving, only during sustained driving at a steady 1800-2200 RPM in 4th and 5th gear. Put quads back on and noise will still come. Strange thing is that it is almost like the car must be warm for it to occur, and once it starts you can come to a complete stop, start up again and it will not occur. Honestly sounds like the drive shaft, but no marks or anything show up.

Any ideas?

 

[90lxcoupe]

Did you leave a wrench anywhere on the rearend when the work was done?

 

[Cobra912]

did you remove the exhaust? did you replace any of the bushings?

 

[LX302]

Did you check if your spare or tire iron/jack is loose making the noise? Loose Gas tank supports?
Just thinking of areas where you would have a thump.

 

[mole5430]

Yep, and nothing else seems off. I am starting to think it could be the pinion bushing, but we will see

Thanks!

 

[mole5430]

Exhaust was completely changed, rear end was swapped out of another 89 vert I had. All was great until the new springs and lower control arms were put on. Outside of the new busings on the control arms, no others were changed. Sounds like I need to start there and then possibly the pinion bushing needs looked at two

Will keep you posted