Another G50 mount question

[steely]

Is there an OEM-like replacement part for the G50 transmission mounts?

I am not looking for the harder sport mounts (Wevo, etc), and the only alternative I found in searching so far was the poly replacement our host offers, unless I missed something. I also wanted to shy away from sending the mounting bar out for welding or whatever.

In doing some searching here, I found references to part numbers that seem to be NLA or defunct, but to be sure, can anyone recommend a rubber part, and/or method to press-in a suitable part - assuming the process is possible?

The numbers I came up with, good and bad, follow:
PEL-RSRMTM (Poly-Graphite Insert Kit) for (1972-89) 915 or G50 (currently my only option)

PEL-MTRMNT - pn from a previous thread, but can't find in catalog
911-374-040-K1-M285 - can't find in catalog
911-375-043-07-M61 - ditto

Thanks,
Dan

[Por_sha911]

Bump for a good question.

[gsmith660]

Are you looking for a crossmember to adapt an earlier car to the G50 or just looking for the tranny mounts that go on the crossmember? Patrick motorsports makes a crossmember $$ or look at this page for how a crossmember was modified: http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/529504-what-best-tranny-use-these-exotic-builds-2.html

[steely]

Thanks Joe and gsmith,

No, I wasn't looking to do any mods, I just wanted to refresh my stock setup. I have all G50 components now and wanted to see if there were any newer developments to replacing the existing (pressed-in) rubber mounts.

According to an answer I just received today from our hosts' support, only the PEL-RSRMTM is an option (poly-graphite). The other parts I got from searching what other methods folks were looking into. The other parts I listed are NLA or superseded and/or not applicable.

I found another thread where a guy pressed the old one out, so I was hoping someone made one that could be pressed back in. (kinda like the suspension bushings). I also didn't want to search for a used part, and while the Wevo mod is fine for many, it sounds like it's more appropriate for a sport setup (stiffer w/improved shift response, but poss. slightly higher cabin noise & vibe).

A change involving a weld demanded more of a certain commitment than I may understand or be ready for. so for now, if I refresh, I'll go with the 2 piece poly graphite kit, and if I don't like that, then I may commit to a sport setup.

Maybe it is stupid, but if the stock engine mount rubber (after pressed out of the housing) fits the trans mount rubber - and I have no dimensions yet - I wonder if that would be worth a try(?) This question has been posted before, but I never found an answer.

[andyt11]

I'm looking at the same problem. I think I'm going to order up the two piece poly bushing like you. However the same question has crossed my mind:

If this poly bushing fits engine mounts and tranny mounts, why cant we buy the rubber from the engine mounts and use them in the G50 mounting bar? Probably can.

[KTL]

Don't assume the engine mounts and transmission mounts are the same thickness of material. While the 915 engine and trans mounts are interchangeable, the G50 appears to have a trans mount of different thickness. My guess is based upon the fact that Porsche spec'd a different mount bolt for the G50 mount. Meaning, if the trans mount rubber was basically the same shape as the previous 915 mount, the mounting bolt should have remained the same.

The G50 trans is somewhat noisy, so i'd not recommend replacing with a higher durometer (harder) bushing material. Doing so will definitely transmit more noise into the cabin. If the material in the mount is still intact with no cracking or other visible deterioration, I would just leave it as is.

A good way to check/inspect the rubber mount is to clamp the mount in place, like on your bench vise or leave the mount attached to the trans (this assumes the trans is out of the car). Insert a rod of suitable diameter and ample length that will allow you to deflect the bushing material side to side. If by deflecting the bushing you don't see any cracking, I would say its still in good shape.

[DailyDriven'88]

Ive installed a set of poly mounts (both engine and G50 trans mounts on the same car) and quite a bit more noise was transmitted into the cabin. If NVH really bothers you, then this option would probably not be for you. I have yet to feel a wevo equipped G50 trans mount so I cant comment on it, but I wonder how it compares. The poly mounts are pretty dang stiff and have almost no give, or at least that what they seem like.

I also recall doing quite a bit of work, for what it was, to get the original trans mount bushings out of the crossmember. Perhaps if they are crumbling they are easy to remove, but if they are still somewhat intact, its not that much fun.

[steely]

Gents - this thread is a few months old, and I am already committed at this point.

Having started the job a few weeks ago and finding the large washers shot (rusted inside face), and having apparently fixed a small leak (another more current thread), I hope to get the poly-graphites on tomorrow.
I'll report my findings about the noise if significant when she's back on the road.

[Canada Kev]

Any news on this?

[steely]

Yes and No. I'm glad somebody is interested, but I am sad that I don't have anything significant to 'report'. The install went ok amid interruptions on Saturday from a painter and 2 other contractors - nobody is on time these days (and neither am I ) but I digress.

Pic below, but I cannot drive her yet - still on stands waiting my front susp. parts to come back from the powder coater. At this point I am hoping this guy can deliver so I can go to Hershey (in April).

This is all I got for now.


more off the subj - This was part of a decent winter project - replaced engine mounts, pass side cam twr oil line, rear shift selector boot, addressed(?) front trans cover stud leak, cleaned local area. Front susp bushings, rack clean and lube, turbo-tie rods, ball joints and painted front hardware. Would have done the trans mount too, but lost faith in the coater.

[Canada Kev]

Yes, I'm interested. Most don't seem to have a lot of experience with the mounts for G50s. I'm looking at this myself and am unsure between the (apparently) only two options: Wevo and the poly that you've used. Go guinea pig, go!

[steely]

(chuckle) yeah, somehow this did feel like new ground, but then it's all new to me. As a reminder to myself I will try to bring some news related to shifting, noise (although it is a targa), vibration, and increased horsepower. ;-)

Can't comment on 901/915s either, but for the install I had to adjust the lift of the trans slightly off the wood blocks I had in order to line up the bolt & new mount(s) to the threaded body-mounting holes. Since the bushings were new, in 2 pieces and not under compression, the lower larger half tended to hamper this 'alignment' process, and I did not want to mess up the threads. I could not start both sides easily until I tried this. This probably would have been second nature to a seasoned mech.

[Blade1055]

Dan,
Any Update on noise / vibration?

[steely]

No update - she's still on stands unfortunately.

[SuperOldSchool]

Sorry in advance for this dumb question, but I am now totally confused. From what I have read, the 87-89 trans mount bar has the rubber bushings built in, and they cannot be replaced. From your picture above, it looks like you did replace the rubber. Did you actually replace the entire bushing, or is it some kind of insert that fits into the existing rubber one and reinforces it?

Thanks
SoS

[steely]

UPDATE

It's been 2 months since the install and today was the first day I got to drive her around the block with the new mounts (and the tie rods and bushings etc).

Car needs an alignment from the main project, but:
I couldn't comment on cab noise (top was down).
She didn't blow up.
Actually felt like it shifted better.
Will post again once I drive it more.
Man did it feel good to drive again - it's been months - so I could be biased.

[SuperOldSchool]

Hello! So how is the setup working for you?:

PEL-RSRMTM (Poly-Graphite Insert Kit) for (1972-89) 915 or G50 (currently my only option)

[steely]

sorry I didn't see this post/question earlier.

I am ignorantly happy :-)

[kojo911]

If the poly bushings don't work out you can fab a 915 mount to adapt to a g50, or just buy the Patrick Motorsport mount. The advantage would be you could use stock mounts.