on my 86 rx when i take off there is a hard thump from under my seat it does the same thing when i hit the brakes i thought it was the rear cv axle because it was bad.. so i changed that and it still does it.. it feels like the driveline my come up into the seat lol.. not sure it is because its lowered and the drivline sits at a bad angle or what but i am getting really upset with it if anyone could help that would be great.. it does have a center bearing on the drivline but i cant seem to find them at any auto parts stores

Those center bearings don't come of easily. I bought a used driveshaft with less than 125,000 miles. My first driveshaft bearing lasted 325,000 miles.

 

Look for wear spots or impact marks on the undercarriage. Especially around moving parts like the driveshaft knuckles. The shift in the balance of the car, may compress the body down to hit some portion of the driveshaft. The only fix may be to raise it back up.

oh i plan on raising it back up this week if i would have wanted a lowrider i would have got a honda  i think a subaru should be a subaru just my 2 cents lol 

 hi,

  i would suspect the rear transmission mount(s)  allowing the trans to lift and thump the tunnel. ? if it's a 4x4

 might also check the upper front mount on the rear diff ,  the one that attaches to the rear suspension crossmember .

Edited October 23, 201312 yr by ruparts

Just because it's easy to do and it'll rule something out if this isn't it;

 

Check your front brake caliper. Raise the car up, pop off the wheel and grab the caliper and see if it has any play. Take out the bottom (14 mm I believe) bolt and swing the caliper up and then slide it off the top bolt and then check that top bolt to make sure it is tight.

Just a thought.

Also check:

 

- the stay pitch rod or what ever it's called - the one from the engine to the firewall.

 

- gearbox crossmember bolts

 

- centre bearing bolts

 

- rear seat is bolted in properly

 

- nothing is loose in the storage space in the boot - something could be rolling around in there...

Cheers

Bennie

transmission mount. squeeze some 3M windo-weld urethane from a caulk tube in the bbushigns to beef them up. They probably have separated. Let the product cure for 24hrs before driving or it will squeeze out.

 

...if you cannot find oem replacements

Edited October 25, 201312 yr by MilesFox

well i put it back to stock height well its a little taller then stock i used wagon struts and springs and the thumping is not as bad now but it drives so much better