Tools needed for 915 rebuild?

[GaryR]

I'm amassing the tools I need to properly rebuild a 915 as it's a "wear item" on my race car. So far I have:

Engine stand/yoke to hold it
Synchro Hub Removal Tool(s) - 1&2, 3-5
Shift Fork Jig
5T Press
IR 2 stage compressor and 1/2" impact
24mm, 36mm sockets

What else, besides knowledge, do I need?

Thanks!

[yelcab1]

A dead clutch plate
A very large socket (cannot remember the size) to undo the nut holding the gear stack together. It also needs to be modified.
You need 2 synch tools
A torque wrench up to 200 lbft
A digital camera

[GaryR]

Originally Posted by yelcab1

A dead clutch plate
A very large socket (cannot remember the size) to undo the nut holding the gear stack together. It also needs to be modified.
You need 2 synch tools
A torque wrench up to 200 lbft
A digital camera

Thanks Yelcab-

I believe I know what the "dead clutch plate" is, and old friction disk with a bar welded on to hold the mainshaft from turning, correct?

Large socket I believe is 36mm (I have that and all below it), in what way does it need to be modified?

What are the two "Sync tools"?

TQ wrench and iPhone, check.

[Bob Kontak]

Tom Petruska from Mayo sent me some pics during my 915 rebuild.

I gotta think this is the socket in question.

The previous wrench that worked on it had no socket and used a punch to get the nut off. Then re-used it.

[GaryR]

Ahh, I see. Easy for me to make once I know the size(mm) and length required (in)! Socket, cutoff wheel, length of steel pipe, and my MIG!

Thank you Bob, getting there!

[Bob Kontak]

I think the torque is over 150 on that bad boy. Set your weld up well.

[yelcab1]

Well, Bob spent money on the right 36mm extra long socket. That is the factory tool. If you don't have that, you need a 3/4 inch 36mm socket so it fits over the shaft, then weld a 1/2 inch extension to the side of the socket so you can attach a torque wrench.

The dead clutch plate is screwed into a wall (an immovable object) while you use the 36mm socket to remove and install the gear stack nut. No need to have a bar welded to that.

You need two synchronizer hub removal tools, one for lower gears and one for upper gears.

[Peter Zimmermann]

Welcome to Red Line Porsche Wiki - Porsche Wiki

The above link will take you to my 915 repair Tutorial. Tools are shown/discussed throughout the work, please feel free to print the 9 parts and use them!

Go to the linked site, scroll the left side of the page, click on "915" under "page tags," and you will find the Tutorial's table of contents. Hope it answers some of your questions!

[GaryR]

Originally Posted by yelcab1

Well, Bob spent money on the right 36mm extra long socket. That is the factory tool. If you don't have that, you need a 3/4 inch 36mm socket so it fits over the shaft, then weld a 1/2 inch extension to the side of the socket so you can attach a torque wrench.

The dead clutch plate is screwed into a wall (an immovable object) while you use the 36mm socket to remove and install the gear stack nut. No need to have a bar welded to that.

You need two synchronizer hub removal tools, one for lower gears and one for upper gears.

Got it, wasn't sure what you meant by "sync tools", I have both of them and clarified the 1st post. Understood about the clutch plate, I was thinking steel bar in my vise. I like welding stuff..

Thank you Peter, I have read the tutorial(s) and they are what I will be using!

[KTL]

A hunk of aluminum alloy for "pressing" the gear stacks apart via gravity striking.

Since you like welding and grinding (me too) why not take the center section out of the clutch disc and weld a "V" on it with plate steel legs, to replicate the factory tool that uses the bell housing to hold the mainshaft.

Since you'll be pressing the dog teeth off the gears cold and installing new (freeze gear, heat dog ring), I would highly recommend the new teeth be spot welded on. You don't want your teeth walking off the gear.......

Rig up a T-handle that you can screw onto the shift rod shaft to allow you easy rotation/shifting of the gears.

Heed the experts (not me) advice and do the 930 dog & retainer conversion on gears 3 and 4!

[GaryR]

Originally Posted by KTL

A hunk of aluminum alloy for "pressing" the gear stacks apart via gravity striking.

Since you like welding and grinding (me too) why not take the center section out of the clutch disc and weld a "V" on it with plate steel legs, to replicate the factory tool that uses the bell housing to hold the mainshaft.

Since you'll be pressing the dog teeth off the gears cold and installing new (freeze gear, heat dog ring), I would highly recommend the new teeth be spot welded on. You don't want your teeth walking off the gear.......

Rig up a T-handle that you can screw onto the shift rod shaft to allow you easy rotation/shifting of the gears.

Heed the experts (not me) advice and do the 930 dog & retainer conversion on gears 3 and 4!

Thanks Kevin, what does the 930 conversion accomplish?

[KTL]

It uses a better synchro retaining system than just the wide "outie" circlip on the 915. This circlip is known to distort (check it on a flat surface) and come free, releasing the synchro bits. It gets ugly in a hurry after that.....

915 4th gear issues

[Bob Kontak]

Originally Posted by yelcab1

Well, Bob spent money on the right 36mm extra long socket. That is the factory tool.

The tool is Mayo Performance's. They e-mailed me pics of progress.

FWIW - When I saw this pic of their tools on the wall, coupled with the well under $1,000 labor for dismantlement and re-assembly (UPS'd it to them), I felt pretty good about not spooling up for the project.

[Jon B]

Originally Posted by yelcab1

Well, Bob spent money on the right 36mm extra long socket. That is the factory tool. If you don't have that, you need a 3/4 inch 36mm socket so it fits over the shaft, then weld a 1/2 inch extension to the side of the socket so you can attach a torque wrench.

41mm for 915, not 36mm.