Updating 901 transmision mounts

For 911’s prior to 1972 it is necessary to replace the complete transmission support bar with the mounts included as the transmission mounts can not be individually replaced.

Is it possible for me to replace the transmission support bar under my 901 transmission with a later model which will allow me to replace the mounts.

Allan,

If your trans. crossmember looks like the one on p. 148 of the Haynes manual, then, no I don't think there is enough room for the later style crossmember, but it might be possible to adapt the later replaceable mounts by doing a bit of cutting, grinding, and welding. It looks like there is JUST enough room to attach the mount diagonally at the end of your existing crossmember! I suggest that the forward 8 mm holes be further apart than the rearward pair, that is, about 1" difference left-to-right from the left forward holes. If your existing 14 mm bolts are 15" center-to-center, then the forward 8 mm holes would be about 16" apart, and the rearward 8 mm holes about 14" apart. I hope this makes sense!

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Warren Hall
1973 911S Targa

Warren, thanks. Yes you do make sense. First I’m going to make a drawing of my transmission support. Then I’m going to see a friend with an ’84 - 911 to see the difference and if it’s possible what will be required to make changes.

My other thought is to make some large steel or aluminum washers to put over the existing bearing to take out the slack. Do you think this is feasible or a dumb idea.

Allan,

No, the washer idea sounds feasible, and maybe workable, too, at least on a temporary basis. Another thing might be to get some of those large 3" diameter 'lift kit' bushings used for 4x4's and trucks for off-roading' vehicles andput one below and then your washer to hold the crossmember in place ... it would probably take a longer 14 mm bolt, such as the one theough the rear mounts, or maybe the lower shock-mounting bolt of a '72-'73 model.

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Warren Hall
1973 911S Targa

Warren, thanks again.

For right now I’m going with the lift kit bushings or washers to tighten up the bearings. It’s a quick fix.

Then I’ll find a newer support bar and see what is required to modify it for the 901 transmission. It’s a better long term plan and I can post the results for anyone with a pre 1972 car who runs into the same problem.

Regards, Allan.

I've been wondering what to do with the original tranny mount on my '66 912 project-I just couldn't figure out how to to remove the old rubber bushings from the steel crossmember and pop in new ones. I figured the factory must have had some type of huge press or something to squeeze the hourglass-shaped rubber bushings into the mounts. The rubber bushings themselves look to be the same ones used for the oval motor mounts, but I've pretty much decided that I'll have to replace the entire tranny crossmember just because the rubber mounts are getting old and cracked-but if there's a fix out there (like using the body lift-kit bushings Allan is going to try) speak up and let us know.

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Clay Mcguill www.geocities.com/the912guy

Oops!

[This message has been edited by Allan Broadribb (edited 01-23-2001).]

That's right, you have to replace the complete cross member with the bushings included - that's if you can find a new one. I think the final answer is to modify a newer cross member with replaceable bushings to fit the 901 tranny. In the meantime I'm going to try the quick fix.

I'll keep you posted on my progress.

Allan