915 clutch

[kavadarci]

Hi,
Have not been posting here and neglecting (not driving) my 911 as i've been restoring an old rusty 79 w123 diesel which is finally done and on the road.
After driving it (it's a diesel, it's a heavy car and it is slow compared to the 911 and very different car), it just made my appreciate the type of car 911 is even more.
few photos of the merc:


Back to the 911:
Since i got it 3 years ago (the car was sitting for 12 years) the clutch was stuck and thanks to suggestion from a forum member to start the car in gear the clutch got unstuck and the car has been on the road ever since but one particular problem persisted.
In first if i try to release the clutch slowly there are major vibrations and not always, the other gears are ok and the clutch does not slip.
I believe the clutch needs replacement (can not confirm if original but probably yes) and these vibrations are just not pleasant.

I appreciate any feedback on what might be causing these vibrations and what clutch kit to get as i see few available ranging from 270 to 1300

Thank you
1976 911 2.7 targa with 915 transmission

[gomezoneill]

The flywheel needs to be resurfaced, possibly rusty with high spots. Also the disc may have broken in spots from being stuck to the flywheel. Do not continue to drive it.

I used to work on Mercedes cars back in the 70's, the two door 240D were a nice car easy to work on very dependable. We didn't have 300's here in the USA. (except for a rare grey market).

[john walker's workshop]

Could be a cracked release fork, oil on the disc, a clutch cable sheath broken internally, even old motor/ trans mounts. The clutch cable needs to arc upwards over the throttle bellcrank to get some drag to control the inner cable. Seen several routed under it. (VW Bugs shudder because the cable sheath doesn't have enough arc. Stack some washers on the end to force a curve and it works properly.)

[porsche930dude]

I would purposely "burn the clutch" a few times to wear it in a bit and burn off any rust. I know everyone is cringing but youve got nothing to loose

[proporsche]

all of the above..just one thing,,check if your 15mm nuts which holds the trans.to the engine are tight

Ivan

[JohnTucker]

Originally Posted by john walker's workshop

Could be a cracked release fork, oil on the disc, a clutch cable sheath broken internally, even old motor/ trans mounts. The clutch cable needs to arc upwards over the throttle bellcrank to get some drag to control the inner cable. Seen several routed under it. (VW Bugs shudder because the cable sheath doesn't have enough arc. Stack some washers on the end to force a curve and it works properly.)

THAT is really interesting! Going to go check and see how I routed my new replacement cable a few weeks ago. I don't recall.

[kavadarci]

ok,
engine trans mounts are new, cable is router properly and new and the clearance is as per manual.
i will check the arch of the cable.
I also confirmed with the previous owner, clutch has never been changed since 1976.

[darrin]

Originally Posted by gomezoneill

I used to work on Mercedes cars back in the 70's, the two door 240D were a nice car easy to work on very dependable. We didn't have 300's here in the USA. (except for a rare grey market).

I recall seeing (and wanting to buy) the 300cd turbodiesel coupe at a dealer in the early 80s -- per https://en.wikipedia.org/wiki/Mercedes-Benz_W123#Coupé_(C123) looks like they made it to the US in 1981?

[kavadarci]

300CD non turbo and turbo were available in the US and Canada, rare but available.