Help!
After several speeding tickets, I finally took my SN95GT into a local speed shop in town to have my 3.73s taken out and 3.27s put in.
When my car was done, I noticed a clunking noise in gears 1 through 4, mainly in the lower gears when sloppy or lazy with the clutch (esp. around parking lots). I took it into another speed shop and they mentioned something about backlash not being set right or not shimmed up right. The other speed shop said that it was just a sloppy install job.
So I call the guy and he tells me that he's been in bus. for so many years, he knows what he's doing and that some clunking is actually normal (huh?). He also said that though they were used gears, he did them to spec (.008 to .015) bla bla bla.
He said maybe it's some other part of the drivetrain; axle spline or spacers or U-joint and on and on. He asked me what should he set it to to make me happy? I'm not the expert I told him, that's why I took it to you because you're the professional! He said well if I set it higher you may hear a whine, if I set it to spec (in the middle he says) and you're getting a clunk then I don't know why you are suggesting that my install job is the problem.
I told him, I don't know what is to blame, All I know is I never had this problem when I bought the car with the stock gear, nor did it clunk with the 3.73 gears. Only after I took the car to him did the car started clunking; like a wooden spoon banging an aluminum pot when downshifting at low speeds.
Not sure if I should take the car back to him. God forbid he says yeah the problem is elsewhere and not in his install. Why all of a sudden these other parts come into question is beyond me. My aluminum driveshaft with U-joint has less than 10k miles on it.
My suspicions tell me that he may be pointing the finger in other parts of the drivetrain/axle and "apparently" replacing stuff that's not broken while he fixes the problem he caused with the install.
Am I being taken for a ride or is there merit to the idea that other sources may be causing the problem?
But why would the clunking noise happen only after he did the gear swap?
Were the used gears to blame? Were they worn enough to cause this problem?
Yep, I think the gears might be more worn than 1st thought. but....
Thanks for the quick response...!
I don't know much about what goes on with the ring and pinion gear as far as wear goes. However, would setting the backlash be based on the parts themselves regardless of wear?
Clunking Noise from improper backlash. Safe to drive?
I talked to the guy at the shop and asked if it was ok to drive like this and he said yeah, shouldn't be a problem. I'll keep it under the speed limit til he fixes it but I was wondering:
Under safer than normal driving conditions, what damage if any could happen from the gears not being set up right ?
WEll if the pinion and gear are nto meshing properly, it could slowly grind the teath off. Which when you brak a couple of weekend teeth and that carries over into the bearings and axle takign the load, you could basically explode all the "stuff" in the pumpkin. Worse case, it locks up sending you into a skid and lockign the motor up. Normally just a free sping of the driveshaft with grinding noises.
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2006 Mustang GT in Torch Red
C&L Intake, Evolution Performance Tune, Borla Axle Backs, Hurst Shifter, 4.10's, JBA Long Tubes, Prothane Engine Mounts, Steeda UDPs, FRPP Charge Motion Delete Plates
I would have used new parts myself...but that guy i wouldn't let him near it again, its hard to tell what is causing the noise, but its gotta be the rear end of course, like they have said worst case the rear end will lock on you if you are lucky it will shave it self and you just wouldn't be able to go anywhere, the aluminum driveshaft will only make the nose louder, not wreck or be the cause
sound like a backlash problem, that guy just doesnt want to take responsability. i wouldin't take it back to him. some one that would know what they where doing probably wouldint even use the factory specs. on a used set of gears.
Same thing just happened with me. Went from 2.73 to 3.55 and now every time I clutch and every time I shift, I hear a distinct clunk. Can't tell if its from the rear or from the tranny though. Watched the guy install the gears, and I know he shimmed the differential properly because I was watching him set the grease pattern on the teeth and there wasn't a significant amount of travel from forward and reverse rotation.
Got the same response when I called him up about the noise too - that the differential was set up dead nuts and that the clunking couldn't be generated from the differential itself in that there isn't anything capable of clunking back there.
However, the clunking didn't exist before and it definitely exists now. This isn't the first post I've read about this though and nobody seems to have a real answer as to what the problem actually is.
Would be nice if there was a definitive culprit/solution.
Same thing just happened with me. Went from 2.73 to 3.55 and now every time I clutch and every time I shift, I hear a distinct clunk. Can't tell if its from the rear or from the tranny though. Watched the guy install the gears, and I know he shimmed the differential properly because I was watching him set the grease pattern on the teeth and there wasn't a significant amount of travel from forward and reverse rotation.
Got the same response when I called him up about the noise too - that the differential was set up dead nuts and that the clunking couldn't be generated from the differential itself in that there isn't anything capable of clunking back there.
However, the clunking didn't exist before and it definitely exists now. This isn't the first post I've read about this though and nobody seems to have a real answer as to what the problem actually is.
Would be nice if there was a definitive culprit/solution.
Well, roast the hell out of the tires or dog it til the clunking stops. Whatever breaks, that was the culprit.
You can see if it is the gear install by jacking up the car and grabbing the drive shaft and work it back and forth to see if the pinion mount moves. It is usually that the pinion nut was not torqued enough to crush the sleeve or the drive shaft is not tight to the pinion mount.
After Gear Install I hear a Clunking Noise 
Yep, I think the gears might be more worn than 1st thought. but.... 
