Help with Solid Tranny Mount Install

MAS956 · 02-12-2003, 06:52 PM

List,

In my seemingly never-ending quest to improve shifting of my 915 tranny, I just bought solid mounts for our host that I want to install tomorrow. The form factor is different from stock and therein lie my questions:

I assume that these things mount with the conical section in (up) towards the body, right?

Also, will I reuse the large washers from the stock mounts against the flat surface of the solid ones? Seems like I'd want something between the bolt head and the mount surface. Anybody know torque specs offhand? I think I read 58 ft-lbs. for the 14 mm bolts. How about the 8 mm ones?

This may all be painfully obvious once I get in to this, but I really like going in with a plan.

If my questions are stupid, I'm sure I'll be told - that's what I really like about this board.

Thanks!

Tyson Schmidt · 02-12-2003, 07:07 PM

If I may make a suggestion, please replace the engine mounts and not the trans mounts.

This will hold the engine and trans more securely since the wide spacing of the engine mounts gives them more leverage against twisting than the trans mounts. Also, it will transfer far less tranny noise into the cabin.

I've tried all different combinations on several cars and the conclusion I came to was to use solid for the engine mounts, and sport mounts for the trans.

But to answer your original question, the trans mounts point up and the engine mounts point down.

MAS956 · 02-12-2003, 07:48 PM

Thanks Tyson,

Should I also use the large dished washers with the solid mounts?

Tyson Schmidt · 02-12-2003, 07:50 PM

Nope.

MAS956 · 02-12-2003, 07:59 PM

How about a flat washer? Any washer at all?

Thanks,

Tyson Schmidt · 02-12-2003, 08:15 PM

You'd use a lock washer on the nut end and a flat washer on the bolt head end.

MAS956 · 02-12-2003, 08:25 PM

Thanks, Tyson!

jwetering · jwetering's Garage

I did this conversion on my 78 SC (solid mounts rear, sport mounts at trans) and it's GREAT! (say this in your best Tony the Tiger voice).

02-13-2003, 09:22 AM

Is shifting improvement the main reason to go for solid mounts at the engine? Do they also increase chassis rigidity? Is engine noise & vibration increased noticeably?
Thanks,

pbs911 · pbs911's Garage

Quote:

Is shifting improvement the main reason to go for solid mounts at the engine? Do they also increase chassis rigidity? Is engine noise & vibration increased noticeably?

I followed Tyson's advise and went with solid at the engine and sport at the trans. I also upgraded to an apex shift coupler at the same time. Shifiting is more precise. There is some increase in engine noise in the pasanger compartment but not unbearable. I noticed no increase in vibration with this set up.I noticed the car seems more responsive when giving it the gas, probably due to less twisting in the drive train. This is a great upgrade for the cost.

Doug Zielke · 02-13-2003, 05:36 PM

Add my car to the list of happy users of solid engine mounts (Smart Racing), and Club Sport-type (Porsche) trans. mounts. The first time I drove the car since adding them, I was very impressed at the shifting improvement. I found *no* additional noise transmitted into the cabin, either. And Paul is right....there is a definite sensation of improved acceleration, probably due to less "wind-up" of the soft rubber mounts.

Don Plumley · Don Plumley's Garage

Looks like PO had the motor mounts replaced with Sport Motor Mounts (911 375 043 07). Are these the same as the Tranny mounts? If so, can I just get the solid mounts, and swap?

Mike Feinstein · Mike Feinstein's Garage

Is there any reason to do this mod on a G50 Carrera?

Doug Zielke · 02-13-2003, 05:54 PM

Quote:

Originally posted by Don Plumley
Looks like PO had the motor mounts replaced with Sport Motor Mounts (911 375 043 07). Are these the same as the Tranny mounts? If so, can I just get the solid mounts, and swap?

Yes!

Don Plumley · Don Plumley's Garage

Thanks Doug!

Oh Wayne...

Mike - I have a G50 3.2; I think the vehicle dynamics are the same, so it's a way to stiffen up the motor to chassis connection. Don't know if the 915's are any more or less sensitive. It's now on my todo list, when I get around to it I'll let you know.

Don

jrb964 · 02-19-2003, 02:04 PM

Mark -I'm thinking of doing the same thing after rebuilding my tranny. It's great to get this valuable advice....What has been your out come with replacing your mounts?
John
'80SC Weissach
'91 C2 Cab Tip

MAS956 · 02-28-2003, 04:53 PM

I'll let you know in a couple of days, John. I was going to just replace the tranny mounts but decided to do all four after this thread. I just got the sport mounts today and will follow the conventional wisdom of solids in the rear and the sports @ the tranny.