Drivetrain vibration?

kennyo

Registered User
I've got an 89 sc with 90k. My son has been driving it the last 3 months. I just got it back and it has a bad vibration over 20 mph when you coast or push in the clutch. It's not as bad under load. Any ideas what to look at? I'm going to check the u-joints and tighten stuff up but you guys always know about the quirks of s/c's so I wanted to ask. Thanks.
 
check 4 capscrews at back flange

I've had these loosen up on me and experienced a similar situation ... underload things tighten up ... let off the gas ... slack develops and then you get vibration
 
Yea I had a similar problem as well, it turned out to be the drive shaft bolts, they had worked themselves loose, tightened them up and no more vibration, same symptom, on load it was fine but when you let off the gas big vibrations.
 
Just another thought-what about motor mounts?

Speaking of "bad vibes", what about the motor and trans mounts on these cars? Owning two '95s, and having been a member here for long time, I would suppose at 90k you should have already gotten rid of the liquid filled stock mounts and installed the solid rubber ones from MN-12. Good investment.

Don

'95 auto with 165k, daily driver, full SCP exhaust, Kooks headers, 75mm MAF/TB, 5% OD pulley, Brian Herron chip, getting a little tired but runs good.

'95 5-speed with 25k, full SCP exhaust stock headers, soon to have ported Sc w/MP inlet plenum and bigger MAF/TB?intake &filter
 
I had similar symptoms on a 93LX I once owned. Turns out the driveshaft was warped, and vibrated at one certain speed. I got a used one from Rod and it was all cured. I could have had it rebalanced though. These shafts are hollow and any bottoming out of the car can warp them, I think this one was bottomed out on a trailer when coming off.
 
Back
Top