924Board.org

[DLC360]

OK, first off im 53 years old and not some kid beating my car to pieces all day long. My ride is an '87 924s with 135k on it. Nothing out of the normal, just a stock car under the hood. This is not the first manual shift I have had, but it is the first hydraulic cluch car for me.

Just after I bought the car, I had a new cluch and ALL related parts change. These include, cutch (vertex "italian clutch"), pressure plate (Sachs), throwout, guide tube, shift fork & bearings, rear engine seal,slave and master cylinders and hoses, all new bolts & anything else that was needed. The hydraulics were flushed & filled fresh and the flywheel (the only part I didnt get new) was machined. The clutch hits very well and is very strong.........unless I am doing city driving, then it seems to heat up very quick and starts to slip. Did I overlook something with the clutch work or is it just my driving style with the hydraulic system ???

Any advice or tips would be very welcome. Thanks in advance.

[ideola]

I don't think it has anything to do with the system being hydraulic.

I'm not an expert on the 2.5L cars, so take this with a grain of salt...but the immediate things that come to mind are:
1. Sub-par clutch disc...the "Italian" disc from Vertex has been reported to be a good alternative to the more expensive Sachs, so this seems a bit unlikely.
2. Oil leaking from the rear main seal. If these are not seated properly, they will leak, and it's possible a shop inexperienced with the 2.5L engine may not have properly bottomed the RMS during install. If oil is getting onto the clutch disc, it would certainly explain the slippage.
3. Incorrect installation of shims on the throw-out bearing. The T.O. bearing comes as a kit that has to be assembled. If the incorrect number of shims were used, you could be slipping the clutch without realizing it.
4. Clutch pedal needs adjusting. There is a minor bit of adjustment that can be done at the Clevis joint that connects the clutch master cylinder rod to the clutch pedal. Again, if it's misadjusted, you might be inadvertently slipping the clutch.
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erstwhile owner of just about every 924 variant ever made

[Kens_74_911s]

Lets keep it simple...
If its traffic stoppage and clutch is in, is there an impression from your post that it's still engaged and heating up. Long traffic stoppage = use netural even then the clutch disk should still not be heating up. How about a good bleed on the system if there is air in the line it coulld influence and modify the true hydraulic action. Air in the system could have potential of soft pedal and or lack of true/positive hydraulic clutch retract.
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Ken - ebay: wandrey1 , *0 , *00 , *01
74 911s widebody
96 BMW 750iL
99 BMW 328i
81 VW MK1-1.8 GTI, 5 spd Pickup
02 Explorer (wife's)
92 BMW 735iL Parting
84,85,86x3,87,944. 82-924,88-924s parted
68, 70, 72, 73, 911~ 70,73 914 past Pcars

[Rasta Monsta]

Check pedal adjustment. There is actually a good amount of adjustment at the actuating rod, and it is conceivable that someone in the past adjusted it to make up for failing hydraulics, and now that your hydraulics are new, the clutch is being slightly actuated even with the pedal fully up.

Oh, and +1 on the Vertex discs. . .excellent.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[DLC360]

Thanks for the info.

I am going to go with the system bleed and adjustment, taking it to a local shop that knows these cars and see how that works. The one thing I have been worried about was if the flywheel was done right, if the step was machined down with the surface. Is there a way to check that with everything still in the car?

All my prior manual shift cars had a mechanical clutch and its just a diffferent feeling than the hydraulic. When driving, I dont sit with my foot on the pedal, its always to the left on the floor. When I stop I dont even try to downshift to slow down, i'll shift to neutral and use the brakes to slow down. When I do need to downshift for a turn or something, I do my best to bring the rpms up enough so there isnt any "jerking" slowing or starting.

Again, THANKS for all the input.

[Rasta Monsta]

I can send you Porsche shop manual pages for actuating rod adjustment if your tech wants them.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[DLC360]