Easter Sunday SC engine drop - got a couple of questions

[cantdrv55]

Celebrated Easter with the family on Saturday instead. Got tired of the "Liberals Have No Honor" thread in OT so I thought I'd drop the motor. Actually, ever helpful Vash lit a fire under me to get the clutch job started so that I can do track day with the rest of the Bay Area Pelicans on 5/26 at Thunderhill.

Questions:

- when we pulled the axles off the tranny, we noticed tranny fluid leaking out from the CV boots. What can cause that?

- the flywheel seems to be missing the pilot bearing. Did Porsche not use a pilot bearing on the '79 SCs? I can't imagine that the Porsche shop (great local reputation) that the PO used 4 years ago left it out by mistake. The reason we're doing the clutch work is that the pedal is extremely stiff and we've eliminated all the easy stuff already.

TIA for your advice.

[yelcab1]

Chris

1) it would not work well without a pilot bearing. Get one and use it. It's cheap.

2) Inspect your tranny drive flanges to see if it is cracked, or have a bad seal ? It is pretty strange to have tranny fluid leaking out from the CV joint, unless the po put it there.

3) Some of the pedals are just like that (my 84 was), but a fresh cable, rebuilt pedal box, and a new clutch will certainly solve your issues.

Like the avata, can you send a big version?

[Jim Smolka]

Also, to get a smooth operating clutch in a 915 gearbox, there are a couple of bushings in the case that are good to inspect and replace. There is also a needle bearing in the clutch lever arm.

'While the motor is out'... it is a good time to replace the oil ring in the engine's thermostat and the oil pressure switch. One can also replace the seals for the engine's oil cooler and inspect the top of the piston cyl for debris

[cantdrv55]

Originally posted by yelcab1
Chris

1) it would not work well without a pilot bearing. Get one and use it. It's cheap.

2) Inspect your tranny drive flanges to see if it is cracked, or have a bad seal ? It is pretty strange to have tranny fluid leaking out from the CV joint, unless the po put it there.

3) Some of the pedals are just like that (my 84 was), but a fresh cable, rebuilt pedal box, and a new clutch will certainly solve your issues.

Like the avata, can you send a big version?

Hey Mitchell,

I'm going to order the pilot bearing. Can't believe the shop left it out!

I'll check out the tranny flanges too. When we removed the boots, the fluid leaked out but none since.

Vash rebuilt my pedals already and replaced the cable 2X, no go.

I got my avatar from ZOANAS (who else). I'll let him know you want a bigger version. He'll probably post it on BAP below.

http://groups.yahoo.com/group/BAPelicans/

[cantdrv55]

Originally posted by Jim Smolka
Also, to get a smooth operating clutch in a 915 gearbox, there are a couple of bushings in the case that are good to inspect and replace. There is also a needle bearing in the clutch lever arm.

'While the motor is out'... it is a good time to replace the oil ring in the engine's thermostat and the oil pressure switch. One can also replace the seals for the engine's oil cooler and inspect the top of the piston cyl for debris

Hey Jim,

My list of "while it's out" is growing. I'm doing the t-stat oil ring and pressure switch. Are you referring to the shifter bushings in your post? I'll also get the bearing in the clutch lever arm. Thanks.

[vash]

the TO bearing jiggled within the pressure plate, and also the TO fork was missing the two bushings on either side.

none of which can be good.

[Blanco]

Whats with the disguise?

[Jim Smolka]

cantdrv55,

The bushings in question are the 3 that are in the case of a 915 gear box. The shaft that connects the clutch lever arm to the TO bearings C shaped clutch release fork is supported by those bushings. When removing the shaft, note its position with reference to the case. During reinstallation, rotate the shaft 180 degrees as to change the wear points of the shaft. The bushings should be inspected for wear and replaced if needed (note position of bushings and depth into the case) However they are a pain to replace. especially the top one since it cannot be driven out of the case. Note, many 915 gearboxes have new clutches installed without attention to these details or the needle bearing (and its associated parts) in the clutch lever arm.

[cantdrv55]

Originally posted by Blanco
Whats with the disguise?

I must protect my identity due to my "work with the military".

[cantdrv55]

Originally posted by Jim Smolka
cantdrv55,

The bushings in question are the 3 that are in the case of a 915 gear box. The shaft that connects the clutch lever arm to the TO bearings C shaped clutch release fork is supported by those bushings. When removing the shaft, note its position with reference to the case. During reinstallation, rotate the shaft 180 degrees as to change the wear points of the shaft. The bushings should be inspected for wear and replaced if needed (note position of bushings and depth into the case) However they are a pain to replace. especially the top one since it cannot be driven out of the case. Note, many 915 gearboxes have new clutches installed without attention to these details or the needle bearing (and its associated parts) in the clutch lever arm.

Thanks Jim. I think I know which bushings you're referring to now. I'll check them out and replace if necessary. Any special tools for the job?

[ZOA NOM]

yelcab1, you have a PM

[Jim Smolka]

To remove the two of the three bushings, yes a special tool should be used to drive them out. The third one requires a dremel tool, pliers, etc. The tool is then used to install the new ones. Be sure to note the locations of each bushing prior to removing them. There is a spec in the shop manual that states where each one is to be seated.