915 - 41mm input shaft nut removal

[1980SC]

I'm not having much luck removing that huge 41mm nut on the input shaft of my 915. I'm willing to order the special long socket, P252a, but I don't know how I'll keep the input shaft from turning? Does this socket use a 1/2" or 3/4" drive?

I could buy a 1 5/8" (41mm) wrench locally, but I don't have an old clutch disk to hold the shaft still. Plus I'd like to be able to properly torque the nut when I'm done.

I tried clamping the 41mm nut in my vice and turning the 27mm nut on the other end of the shaft, but I just break whatever pin I install to hold the smaller nut in place.

How do you hold the input shaft still when using the Porsche socket? Is there a good way of doing this without that tool? I'm going to rebuild my other transmission when I'm done with this one, so I don't mind buying the proper tools.

Thanks,
Rob
1980SC

[tops911]

when I disassembled my main shaft's 41mm nut I did the following. I used 2 "c" clamps and clamped the clutch disc to a work bench, then just inserted the shaft into the disc. I then used a pipe wrench with a cheater pipe and it came off with problem. I'm going to use a new nut so I did not care about marking up the nut. I'll probably have a socket modified so I can reassemble to the correct torque.

[tops911]

I just reread your post, I got ahead of my self. So I'm not going to be any help. Maybe you can find an old disc. I used to live at Fort Bragg, if I was still there I'd let you use mine.
good luck

[ChrisBennet]

I know of three ways to get the nut off:
- I just use the special deep socket
- I borrow an american size plate wrench thingy (square plate with a hex hole the for the nut and a 1/2" square hole for a breakerbar).
- I've seen them impacted off with a air chisel by a high end Porsche shop.
To hold the shaft, I just clamp the splines in a vice with aluminum jaw pads.
-Chris

[1980SC]

Okay, special socket P252a and aluminum vice jaws it is !

Is this socket 1/2" or 3/4" drive?

Thanks,
Rob

[ChrisBennet]

Originally posted by 1980SC
Okay, special socket P252a and aluminum vice jaws it is !

Is this socket 1/2" or 3/4" drive?

Thanks,
Rob

1/2" drive. I don't bother (gasp!) measuring torque on these nuts if I'm reusing the nut. I just return them to the original position. When you punch in the collar, use something with a rounded tip, otherwise you will tear the metal. BTDT. I used a grinder to make a nice round tip on a bolt for this job.
-Chris