Cobra Has Grinding Sound In Rear

[SPICOLI]

Hello all,
I have a 98 Cobra and have had a problem with a grinding noise coming from, what sounds like the rear differential...It only, I repeat only does it when I am going over 55mph and let off the gas or push in the clutch (basically only when the drivetrain has slack and no load on it) It has been doing this for about 4000 miles and I am ready to get it fixed...The car has been lowered 2 1/2 all the way around, it has bump steering, caster camber plates, aftermarket upper and lower control arms and blistien or eibach shocks (dont remember) Also have the hard polyeurethane bushings all through the suspension..I have pulled the read diff. cover and changed oil, the gears look fine..I am thinking that the front bearing on the rear diff where the driveshaft goes to is bad...Anyone had similar problems?? Think it has anything to do with the car being lowered? Thanks, Ron

 

[edwardohaskillo]

Doubt it is from the lowering. Though 2.5" IS a lot. I would inspect the u joints rrrreeeaaaalllyyy carefully if I were you. Especially the front. I've heard they have king cobras in Thailand that can do all sorts of tricks, like open a beer etc. But you don't won't to have the first cobra to learn how to pole vault.

Imagine that lowered rear being suddenly 3 ft off the road...at 70 mph!

Anyway, other than that I have no other advice. Good luck, and maybe do some searches on this and other forums.


cool "call sign" by the way.

 

[Roush21]

Hello all,
I have a 98 Cobra and have had a problem with a grinding noise coming from, what sounds like the rear differential...It only, I repeat only does it when I am going over 55mph and let off the gas or push in the clutch (basically only when the drivetrain has slack and no load on it) It has been doing this for about 4000 miles and I am ready to get it fixed...The car has been lowered 2 1/2 all the way around, it has bump steering, caster camber plates, aftermarket upper and lower control arms and blistien or eibach shocks (dont remember) Also have the hard polyeurethane bushings all through the suspension..I have pulled the read diff. cover and changed oil, the gears look fine..I am thinking that the front bearing on the rear diff where the driveshaft goes to is bad...Anyone had similar problems?? Think it has anything to do with the car being lowered? Thanks, Ron

Dude I also have a 98 cobra and have the same exact thing going on. I am having my U joints replaced right now as we speak. Replace ur u joints dude thats definetly what it is. My car did it when i reached the same 55-60 mph and let off the gas, sounds like a humming and you can feel it coming from the rear right? I thought it was the gears too but its not its the U joints. I went to autozone and got some Brute Force HD U joints (LIFETIME WARRANTY) for $13.99. Make sure you get the front and back, better to do them both when you got your driveshaft off dude. Later

 

[Roush21]

Dude I also have a 98 cobra and have the same exact thing going on. I am having my U joints replaced right now as we speak. Replace ur u joints dude thats definetly what it is. My car did it when i reached the same 55-60 mph and let off the gas, sounds like a humming and you can feel it coming from the rear right? I thought it was the gears too but its not its the U joints. I went to autozone and got some Brute Force HD U joints (LIFETIME WARRANTY) for $13.99. Make sure you get the front and back, better to do them both when you got your driveshaft off dude. Later

Hey I even found the part # for you (How nice am I???) For the Brute Force HD U joint part # is 2-4800BF go to autozone $13.99 a piece man, thats awesome and comes with a LIFETIME WARRANTY so keep the reciept man.