Motor & Tranny Mounts

Superman · 11-05-2001, 01:08 PM

How much of a difference will I notice if I replace all four motor and tranny mounts? The car has 180K miles.

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'83 SC

Bill Douglas · 11-05-2001, 01:12 PM

It improved my gear shifts a bit. I used Pelicans sport mounts. Definitly worth it.

Natchamp · 11-05-2001, 01:28 PM

Can I tag on this and ask a related question? I read somewhere that installing solid motor and tranny mounts would improve shifting too. My question is what are the bad (if any) side effects of solid mounts? Do they resonate noise in the car because of vibration, etc?

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Mark
The Beast
mark@hargett.com

makaio · 11-05-2001, 01:31 PM

I second Mark's question. I would really like to go with solid mounts. I wouldn't mind more vibrations, but I don't want any bad stuff to happen to the chasis.

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Matt Chamblin
78 911 SC

RoninLB · 11-05-2001, 03:07 PM

My 77 has no rattles and I don't want any to occur by stressing body with solid eng/tran/ mounts. It's a street car. It has plastic suspension bushings, but I kept some rubber for road harmonics isolation on shocks and trailing arm upper mount. I will be replacing stock/old tran/eng mounts with cabro/sport Porsche mounts, which are firmer but not "hard". I believe the part number is 911.375.043.07. Girls always like it hard so I may get some heat here on this.

Superman · 11-05-2001, 03:10 PM

Ask BRAINIAC about solid motor mounts. He tried them recently and he apparently is amazed by the increased noise. He says they are not civilized at all. Tyson's not the kind of guy that sticks his pinky WAY out while drinking tea, so I suspect solid mounts do indeed result in an objectionable noise level.

Thanks, Bill. It sounds like it may improve shifting subtly. Any other comments on shifting improvement? This is the improvement I am looking for.

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'83 SC

rattlsnak · rattlsnak's Garage

I have solid mounts on my car, and noticed very little difference -if any- on noise. Much better on overall hard driving though.

liskeard · liskeard's Garage

I replaced my motor and tranny mounts last year with Pelican Sport ones, BUT I also put in a rebuilt Tranny from Vertex at the sime time and didn't notice any difference in vibration OR easier shifting.

Ted

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1980 911-SC Targa

Bill Douglas · 11-05-2001, 06:21 PM

Superman, I've done the mounts and the bushes except the bush behind the gearstick. In other words I've done the ballcup bushing and the coupler bushing. This improved things also. And have done the swepco thing. The gearshifts are still not great. About one shift in ten (approximately) from 1st to 2nd I get a real graunch - doesn't mater if it's a slow or fast shift. This is after a very expensive rebuild by a bad-news outfit here in New Zealand called the Chequered Flag run by a liar and a cheat called Richard Gillies and a company they used called Fast Forward. Also, sometimes it's hard to get into 5th.

The above things I did improved things that were ok, but didn't fix real faults.

J Richard · 11-05-2001, 07:42 PM

I ran the solid mounts for a bit, If you are the type who really loves the mechanical noises you will love these... the amount of noise was pretty amazing. I primarily noticed drive train whine and gearbox rattle, a bit like a touring car, alot of fun, for a little while. Then I noticed a crack where the rear motor mount crossmember is welded to the bolt tube, I never had that happen on a 911 so I went to the sport mounts which were harder rubber, no noise but a much more connected feel in the shifter than factory. At 180K you may need new mounts anyway and I would definately check you shift coupler.

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93RSA

Sunroof · 11-06-2001, 10:38 AM

I just got my new sport mounts for my transmission in the mail yesterday and am ready to go!! One question though....Can I install the transmission mounts with just the rear end jacked up or MUST I level the car to install? I plan on replacing the rear sway bar bushings as well since I have to remove the unit. The 101 Projects, says, take it one side at a time.....any suggestions would be appreciated guys.

Regards
Bob
73.5 T

IMONBOOST · IMONBOOST's Garage

I really don't see the need for solid mounts unless you have a full race car. I installed pelicans sport mounts. Some people invert the huge washer to lessen engine movement but I would not recommend it.

jsmarcus · 11-06-2001, 10:48 AM

I think if you want to replace them, replace with OEM, the solid motor mounts are more prone to failure. There was a thread not too long ago about installation of solid motor mounts and a motor that "fell" out.

You want to improve shifts, play with the linkage and add Swepco, sounds like everyone else has!

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Josh
'84 Carrera Coupe

Nickshu · Nickshu's Garage

Super,

Changed one mount (right rear) because it was notably sagging/cracks in the large washer on top/bottom. Improved shifting ease tremendously. Must have been sagging there more than I thought. My 911 has 81K on it, so an additional 180K may have caused similar wear to what I saw.

I dont know about solid mounts. I once changed the engine mounts in a Saab 9000Turbo I used to own and put one of the pieces on both mounts in backwards....ended up basically bolting the engine right to the subframe....the vibration and noise was incredible!! I know its not a 911, but I dont think I could tolerate that if it were similar...and I'm NO garage queen nor a "flying pinkey tea drinker"

Nick

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Nick Shumaker
1982 911SC Coupe
nickshu@yahoo.com

BRAINIAC · 11-06-2001, 11:42 AM

I agree with J Richard. The solid mounts transmit lots of tranny noise and chatter. I'm sure it depends on the car and the gearbox. Mine is horrendously loud on decel in certain gears and there is some engine vibration around 2500 rpm at times.

But honestly, most of the time it's not noticeable at all. Cruising down the freeway is like usual. It's going through the gears and accel-decel that is nerve racking due to the tranny noise.

All told, I probably have the most to gain with these mounts, due to the fact my car is early and converted to Cabriolet. It stiffened up the chassis rigidity quite noticeably. Coupes may not get the benefit from it that my car did.

If I had a coupe and it was a daily driver, i'd just get the sport mounts. If it is a weekend-only playtoy like mine or a racer, the solid mounts are nice. Noise isn't a factor with a helmet on!

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Tyson Schmidt
72 911 Cabriolet
92 C-2 Cabriolet

tobluforu · tobluforu's Garage

Sunroof, I just installed them on my 72. All i did was raise the rear of the car.

Bill Verburg · Bill Verburg's Garage

I am using custom solid mounts on my 3.6 transplant. No noticeable change in NVH. Trans is ever so slightly easier to shift.

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Bill Verburg
My Home Page

My Pelican Gallery page

My Porsche Owners Gallery Page

Tyson Schmidt · 11-27-2001, 07:45 PM

Just thought I'd add some more feedback on this subject. My 72 had all 4 engine and trans mounts switched to solid. The trans noise was pretty annoying, but it really improved chassis tightness. Since the racing season is over, I took out the solid mounts at the trans and put the stock mounts back in.

The result is 99% less noise/vibration/harshness, and I still have 90% of the benefit from the solid mounts by just running the solid mounts at the rear engine crossmember. It seems that most of the noise is transmitted through the trans mounts, while most of the benefit is from the solid engine mounts.

BTW. Superman, you can borrow my extra set of solid mounts to try out on your SC if you like.

Superman · 11-29-2001, 10:20 PM

Nice to have you back, Tyson. I'd love to try the solid mounts on the rear.

I have changed the shift linkage pieces, well actually I watched and listened while Tyson changed them. they make more noise now, but I don't mind. I think the solid mounts at the tranny end would be obmoxious, and tranny noise is not my favorite. Tranny noise sure reminds me of a race car, but I prefer engine noise.

Heck, I'd probably take the sound pad off and cut holes in the rear deck if I had Webers and exhaust.

rscupper · 11-30-2001, 09:59 AM

I have solid engine & trans mounts. Truthfully so much chassis, engine, and suspension work has been done that I can't tell you what the mounts have done exclusively.

The car is much louder - lots of engine work & added carbs, very loud custom exhaust (can't wait to try the megaphones!), and removal of all insulation. I do notice the trans 'song'. I don't know that the shifting is improved as it was always great, I started with a perfectly solid chassis, and I haven't taken testing to the limit yet. Absolutely no extraordinary vibration.

Yeah, it's loud and it's mean. It's my hot rod