Bumpy clutch engagement in gear

[Won]

It doesn't happen all the time, but every now and then when the clutch is engaged there is a big bump before I let the pedal out all the way. Usually in 3rd and 4th gear, sometimes also in 1st gear moving from a dead stop. Once I'm in gear though, I can disengage and engage the clutch again and it would never be bumpy.

The clutch is old (no record of replacement in the last 12 years, 130k miles on the car now) and probably worn badly judging by the point where the pedal engages. The disc may or may not be rubber-centered. The problem seemed to have gotten worse after the last autocross event with a couple hard launches.

Items checked:
- engine and transmission mounts, rubber still soft and bolts tight
- engine to tranmission stud/bolts
- CV joints show no rotational play
- new Neatrix bushing in the rear, no squeaks from other bushings
- new transmission fluid, checked the guide fork plate

Any thoughts? Thanks!

[Won]

Bump for a bumpy clutch.

[hcoles]

re. CV joints.. no play in joints and no play in attachment to flanges? I don't know much about transmissions... play in ring/pinion/etc.?

[Gunter]

12 years and 130k miles?
Time for the great light-weight sport clutch package from PP.

[Won]

Hey Gunter,

Christmas is near so the budget is tight, but I'll see what I can do

Will check the CV at the flange tonight.

When I shift at a higher RPM I can get into the next gear much faster and the subsequent clutch engagement is always smooth.

[rouxroux]

I had a similar sound/feel last week (although just in reverse & 1st), sort of a "hammer wrapped in cloth" sounding tap/thump...was a CV joint. Very subtle, guess I caught it very early on.

[Won]

rouxroux, was it the CV to flange connection/bolts or the joint itself?

[rouxroux]

It was the joint itself.

[Won]

Jacked up one side of car, put the transmission in gear, and tried to turn the wheel that was in the air. It had about 5 to 10 degree of play, and the inner and outer CV joints were turning at the same rate. On the other side of the differential (wheel still on the ground), the inner CV was moving, but at a much lower magnitude compared to the other side. I'd say not more than a few degrees, while the wheel remained stationary.

Does it tell anything? I assume ANY slack between inner and outer CV is not good.

[hcoles]

in my experience CV joints have very little play in rotation

[Gunter]

Originally Posted by hcoles

in my experience CV joints have very little play in rotation

Correct. Good CV's have no radial play.
Of course, when the wheels are on the ground in normal stance, you can grab the half-shaft and slide it axial about 10-15 mm and that is good.

Won: No miracle is going to occur.
With that high mileage, the spline on the input shaft and the release bearing is as dry as camel ***** in the desert, the guide tube in the 915 is worn, the lining on the disk is gone (It may even be the old rubber-center type), the flywheel probably needs grinding, the cross shaft in the moving the release fork in the bell housing needs lube etc.............
Also, if the CV's have the same mileage, a service is in order meaning cleaning and new Moly lube. If they show galling, new CV's.

I know about the X-mas hype and suggest that you give everybody an autographed framed picture of yourself instead of the usual material goods.
Then you can buy all the parts needed.

[Won]

Well, whatever it was, it failed.

The noise and bumpiness got significantly worse this morning, now exhibiting the backlash in the drive train between on and off throttle.

Taking off from a stop sign, there was a loud clunk. I thought the CV came loose but they're still hanging in there. I can get into gear but there's no power when I let out the clutch pedal, only faint grinding noise. Now I'm stuck in campus waiting for a tow truck.

I'll do the signed photos Gunter. Plus, I can make it easier for them to shop for me since I now know exactly what I want for Christmas

[Won]

All the car's weight was sitting right on the cross beam for front wheel dolly, by means of the gas tank. Now it's dripping gas in my driveway. I'm expecting a call from the manager from the towing company tomorrow morning. Fuck!

[Gunter]

Won:
That sucks. I never heard of a tow on a dolly, always flatbed for 911's.
Take pictures for documentation of the leak.
A new tank etc. could be costly, be prepared for some BS from the towing outfit.
You need a written estimate from a shop for repairs.
And do not just go verbal with the manager; you need to inform the towing company by fax or registered letter noting time and details of the tow with subsequent leak in case they don't take responsibility.
In the meantime, I would siphon the tank the old way: remove the level sender, stick a small hose into the tank, suck and drain into a container.