Knocking out Guide Pins in 901/911 Intermediate Plate

[jluetjen]

I'm in the process of taking apart the intermediate plate(s) from a couple of 901/911/914 transaxles that I have. Two problems I wanted to run by folks before I break something...

1) Guide Pins: What's the preferred method for knocking out the guide pins. I tried to just hammer them through that that doesn't seem to work, they're in too tight. If I heat a the plates by a couple of hundred degrees (I've got an oven in the garage), will that expand the pieces enough so that the pin will be loose enough to knock out? Or will the pin expand as much as the intermediate plate in which case I just have a hot pin that is still firmly attached?

2) One of the bolts holding the bearing in stripped -- no I didn't do it, it was that way before I started. I just made it worse. Any good ideas for how to get it out? Or should I just get out the drill? Luckily I had a second plate which I dis-assembed for the bearings, but now I don't want to leave that stripped bolt there to be tomorrow's problem.

[Grady Clay]

John,

What is the reason for the process?

Are you dealing with the 901 aluminum intermediate plate or the thicker 911/914 magnesium plate?

With the aluminum 901 intermediate plate the pins are solid 10 x 45 mm (900.012.055.00 supercedes to 999.052.016.00 I think.)

With the ’70-’71 magnesium casting the pins are 10 x 50 mm (900.012.028.00).

The transition in ’69 is consistent with the above.

The 914 transmission has the same pin as the 911 magnesium case above 10 x 50 mm (900.012.028.00.)

The specifications on the pin length are for the ground surface, the overall length is a few mm longer.

Tell me more. They don’t move?

Best,
Grady

[jluetjen]

I've got a Weltmeister aluminum 911 intermediate plate that I'm building up. It came bare, so I figured that I'd just transfer everything over from one of the mag plates. One of the mag plates came from a 911 gearbox (although the plate casting itself has a 901 part number), while the other came from a 914 and also has a 901 casting number. So at first blush it looks like they both use the same casting and are just assembled differently.

And you're right -- the pins don't move a bit (and sound quite solid) when I hit on them with a 16 oz hammer. I'm not wailing on it, but a few good sharp hits. I have to check if they're bigger on one side so that they seat on a surface, if they are just a straight pin that can go out from either direction.

[jluetjen]

Hi guys. I'll answer my own question for reference sake. I put the intermediate plate in the oven at 300 degrees for about 10 minutes, and then the pins tapped right out. The pins are straight with no seating surface.

Now on to building up the race gear box!

PS: I hope that I'll be able to afford the race fuel by the time that I get done with this project.

[randywebb]

Now that I won't be hijakcing your thread, John...

Does the Al plate provide a big advantage for a street car? Say one with a much bigger motor in it?

If so, is that for every gear or just some gears?

More directly... should I start saving up for one for when I rebuild my typ 911/01 tranny that is attached to a 250 hp 3.2L motor?

[jluetjen]

It most likely wouldn't be bad insurance given the "big" motor. Especially given the cantelivered 1st gear in the 901/911 box.