cfjan

I have a feeling that those 2 pieces from Porsche Motorsports will be a lot more than the Rennline aftermarket engine mounts.. ha!

Also, engine mounts are easy to get to (just do it with the engine lid open) while the tranny mount is harder...

Dervish

Have a look at this DIY for the updated 997 tranny mount... http://www.renntrack.com/forums/show...t=transmission

Sorry for the cross forum post...

cfjan

Nice, thanks for the link!

Looks like the old version has some empty space on the rubber (not a continuous ring) while the new version is solid across..

I don't have a lift so it is not as easy to change out the tranny mount (compared to the motor mounts).

911SLOW

Called my mechanic and he confirmed, honestly yesterday I couldn't recall that difference..
Mystery solved. : )

cfjan

Sounds like the 997 version is an "upgrade" after all..

911SLOW

touché..

FFaust

All you need actually are 4 jack stands and you're there

cfjan

Maybe I will give that a try.. I have put the car on jack stands before.. ha!

John, got any torque values for those bolts relating to the tranny mounts?!

FFaust

Someone please... cause I don't get it.

From John's diagrams, it appears that with the "OEM" setup, the gearbox goes BETWEEN the two rubber mounts. BUT, with the Cup mount, it seems to be reversed, it's the mount that seems to go between something. What am I missing here?

From the diagrams, it seems to be two totally different installations, but isn't the gearbox casing the same on road and cup?

4porsh

I asked about the $$$ for the cup trans mount over stock. Cup=$1,200 and stock around $250, so stock it was for me. I was also told if you do cup mount you also have to have solid motor mounts.

Good luck.

cfjan

Maybe the gearbox attachment point have a cut out in the middle so the Cup bracket can go in between.. ?!

cfjan

That would make sense to needing a solid motor mount as you wouldn't want the motor to move enough to create any sort of bending moment on the solid trans mount.

The other way around is less critical (my guess, I'm not a race engineer nor have any Cup experience.. ha!) as engine is the heavier of the 2 (between engine and transmission). The chance of the non-solid trans mount allow enough movement to bend the engine mount is less likely than the other way around.

But agree that ideally if one were to go solid, both end should be solid. I think I am going with a second best choice, by putting in a new (arguably, stiffer, due to more rubber, without space) OEM trans mount. At least, that's my logic..

One can probably take the old mount and have a machine shop machine 2 aluminum cylinders and press fit into the carrier and have a solid mount for less than $100? (re-use the old part)

Gofishracing

How many miles were on the car before this failure ? Is this a replace after x # of track days? I'm not sure how to properly inspect. I use to throw parts at my old 79' 930 but I was instructed not to do that with the GT3.

cfjan

I'm sure it has a lot to do w/ how the car is used, etc. But since it is really a wear 'n tear item, I'd think that it is not a bad idea to change it out at a certain interval, consider that it doesn't cost a lot, and for us w/ the 996-3, this version is an "upgrade" (with more rubber).

The description sounds like it is made to supersede the older one w/ 996 part #. (i.e., old version no longer available) So I don't think we are just throwing random parts at it in this case.

Gofishracing

Thanks. My car has the GT 2 RS engine mounts so I'm sure the load is being transferred to the transmission mount.