1993 GT convertible - Slow speed in driveway - 5spd - all rebuilt 5k miles ago w/ new Centerforce dual-friction clutch, rebuilt rear end with extra posi clutches, etc... I checked U-joints by wiggling - no play, motor mounts - tight and no cracks, trans mount tight and no cracks and attaching bolts, etc... looked for exhaust bumping in areas (none seen), and so forth. I put the car in reverse to back it into the garage after driving forward and let the clutch out easy - the car moves as normal 1 foot or so and then a pop sound can be heard and felt through the floor - no other noises or funny things going on. It will also do this when going back into 1st gear - ease out on clutch and go about 1 foot and there is another pop and can be felt in the floor. It does this about half the time. It has never done this before - I have rebuilt everything (total engine out/rebuilt, 5spd trans out and rebuilt, rear out and rebuilt with extra clutches, subframe connectors, etc...) 5k miles ago and it just started doing it 100 miles ago. I do not dog the car - but do accelerate briskly on occasion but the problem did not show up after any particular incident or hard use - just showed up one day after normal use for apparantly no reason. Any ideas? Are the extra cluches in the rear end causing this? thanks....
pop or clunk sound 50% of the time when going from forward to reverse or vice-versa
- Thread starter bsedwebt70-5.0
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Do you think the DS and trans spline interface is loading up as you back up or go forward (suspension articulates a little bit)?
tunedin302
I AM the law!!!
Did you use loctite on the 12mm driveshaft bolts to the rear? If not, they tend to loosen up after a while.
checked the 12mm bolts on the drive shaft - they are tight - I also tried wiggling the drive shaft again - this time there was NO slack in it - on other occasions I have been able to wiggle it back and forth a half inch or so - is this normal? I always have had some back and forth drive shaft movement on all the cars I have checked - maybe it is because it is a 5spd and parked in gear with the wheels on the ground and parking brake set? Nothing looks odd under the car - just your typical slight seeping leak from the rear transmission seal by the yolk....
That is the phenomenon I was mentioning. When the car is in gear (moving forward or R), the splines put tension on eachother. Then the suspension articlulates a little and eventually the force [longitudinal pulling from the articulation] overcomes the spline-tension and the DS will make a thunk noise as the loaded splines move against eachother.bsedwebt70-5.0 said:
Tossing grease on the splines can help the situation - esp. if you address the tailshaft seal and bearing.
Not that any of this is your cause - it's tough to track these things down in person/real time, let alone from a puter.
Good luck.
Do I understand you correctly -- I am to pull the drive shaft and put grease inside the front yolk splines and slide it back on the transmission tail shaft? That seems to make sense - it would make the drive shaft slip in and out smoothly as the car goes over bumps or goes from forward to reverse. Question --- doesn't the transmission fluid lubricate the splines as you drive?
You got it. Trans fluid is not viscous enough to help much with allowing slippage under that kind of load. The trans fluid might eventually wash the grease out, but the greasing is nice for a temporary fix and for diagnostics.
