I've recently encountered a noise from the rear end area of my car and am hoping someone can help me out figuring out what it is. It is directly related to both speed and acceleration. (Louder when accelerating or at higher speeds). The sound is considerably louder in my car because someone cut out a fuel pump access panel from the rear cargo area of the car. Two distinct sounds can be made out, the occurs during acceleration and has a loud whine to it. The second sound occurs regardless of acceleration but varies depending on speed. At low speeds (5-15) its like a knocking sound, while at higher speeds (35-above) it is more like a heavy rattle (same sound, more frequently). I recently (maybe 6 months ago) changed the fuel pump and have just finished upgrading the LCA's, panhard, shocks and springs. I really don't know how to check this problem(its hard to look under the rear end while ur driving). What could this noise be in relation to? Thanks, Efrain.

 

check your u joints and make sure all those suspension parts are tight. if that checks out look for something stuck somewhere underneath the car (like a piece of cardboard from the road) and then check your rear axle gears as well. hope that helps.

 

I very carefully put the car up on stands and set it into drive with the rear in the air. The sound is coming from the driveshaft (yoke?) hitting the intermediate pipe on the exhaust. How could this have happened, I never had this problem when the exhaust was originally put in. Could it have something to do with a lowered suspension? What could be done here? Thanks, Efrain.

 

You gotta move the exhaust enough to accomodate... unless you feel like relocating the driveshaft.

 

Would this mean that the exhaust installer is at fault for improperly installing the exhaust? Like I said, I just recently started having this noise. Would I hold the installer accountable?

 

I, being the idiot I am, forgot why I had bought my adjustable panhard car. I just adjusted it and moved the rear (and driveshaft) away from the exhaust pipe so it would no longer grind on it. With that out of the way, I still got a noise coming from what souded like inside the case of the rear. Again, this noise gets really loud the more acceleration there is. Without the foot on the pedal, it dies down. Any way of checking inside without draining fluids, or removing the rear. Anything else I should be looking for? Thanks, Efrain.

 

you really can't inspect that case without draining the oil and removing the rear cover. It's not that hard to do though... Now that you've adjusted your panhard bar, are you sure you didn't throw of the pinion/driveline angle? If it's out of line, then you probably have to move the panhard rod back where you had it and move the exhaust. It probably had a hanger come loose, just take it back to the shop who put it in you shouldn't have a problem.

 

Sorry man..that sounds just like the noise my buddy's car made right before the axle exploded...so take it easy on her.
This was what happend to his, I hope it is not the same for yours
good luck.
P.S. to drain the oil is a real pain in the butt..but it is the only way to be certain...there is a litttle magnet in there that picks up shards of metal,,,if it is full you know it is only a matter of time

 

I can check the rear while it's still on the car right? I REALLY dont wanna have to pull it off. Thanks a lot for the help guys, Efrain.

 

It's real straight foreward, just remove the bolts and take the cover of, (the oil will come out as wel!).
Just have a new gasket and the right weight and amount of oil to put everything back together.

 

Pulling the cover is the easy part. The smell, oh the smell is the worst part.
[I believe they used old rear end lube in the "bog of stench"]

Refilling it can be a pain if your exhaust is in the way of the check plug. Which it most likley is and you will need a little 4-5$ pump from autozone.

Matt

 

Finally got a chance to pull the cover off the differential, only to discover about five teeth sitting on the magnet. Once everything had drained out I saw exactly what the problem had been. Looked exactly like this guys: https://www.thirdgen.org/techbb2/sho...hreadid=207712 Lost some teeth on the pinion gear too and by the way, turns out the drum rear is not the original 2.73 peg leg(open), but had posi and 3.23 gears on it . WTF? Sooooo, how much $ am I looking at here? Possible new rear end?, sure would love discs in the back.