Powerflex Transmission support question

3177 Views 29 Replies 14 Participants Last post by Dolce86, Oct 22, 2007

Racso

Discussion Starter · Sep 30, 2007

While I was under my wife's Spider repairing the heat shield, I decided to install one of these Powerflex transmission mount reinforcement doodads. The good news is that it cured the shudder the tranny had when starting in first gear. The bad news is that I may have created a new issue. Now when I drive the car, it's loud. Not a bad, tinny, rattly sort of loud, but a deep, solid sort of loud. The source of the new sound seems to be right where the mount is. It only appears when starting and when driving. With the engine running, but not in gear, the car sounds normal.

My question for those of you who have installed one of these - is this new sound normal, or did I screw up somewhere and create a new problem? I'm assuming ( and we know what that leads to) that these things being more solid than the original mount would allow more of the transmission sounds to travel to the frame.

Your help is greatly appreciated.

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Alfajay

· #2 · Sep 30, 2007

Rasco: You had written: "I'm assuming that these things being more solid than the original mount would allow more of the transmission sounds to travel to the frame."

Yea, I'd assume that too. I doubt you have screwed anything up. Those stiffeners are probably intended for competition use, where transmitted noise is a non issue. Sell it on ebay to some racer, and put in a new original mount.

Gubi

· #3 · Sep 30, 2007

The conventional wisdom aroud here seems to be that using poly in the Spider tranny mount causes a lot of noise/vibration issues. Do a search.

Favali

· #4 · Sep 30, 2007

I put one in my 93 about 2 years ago....drove it for 1-2 miles and took it out. I installed the factory support. The part still resides in the bottom of my box of spare parts waiting to be mailed to someone who wants it.

It may be good for a race set-up but for the street it did nothing but significantly increase vibration and noise. IMO, a waste of time and money.

Geezer

· #5 · Sep 30, 2007

To solve my saggy mount problem I shoved some 300psi hydraulic hose in where the lagre cavity should be. Worked great.

CaverDave

· #6 · Sep 30, 2007

I've been running the powerflex support for a little over a year now. No extra noises and no other problems at all. I did replace the Ujoints and support bearing at the same time as I installed the powerflex thing. The closest thing I've had to a problem with it was I had to readjust the metal boot/shifter surround to be able to shfit into 3rd and 5th properly.

David

Racso

Discussion Starter · #7 · Sep 30, 2007

Thanks, guys. I'll probably leave it in until I have to jack the car up for the next thing I have to repair. Unless SWMBO wants it out. After all, it is her car.

Dolce86

· #8 · Oct 1, 2007 (Edited)

Timely post here- for me anyway. When starting from a dead stop in 1st gear, I hear/feel a thumping sound, depending on how many rpms I've got going. I've only heard this in 1st gear and I haven't pushed it in other gears to see if it happens there. I suspect it would but I don't want to beat on the little spider. I thought it was an exhaust mount at first as I've recently replaced the engine and transmission mounts.

It wasn't the exhaust so I had my car looked at by a well respected Alfa guy. He told me the drive shaft was hitting so he put on new u joints and stripped/cleaned/painted the drive shaft. There is no difference and I still have the clunking sound which is easy enough to avoid if I baby it in 1st but I shouldn't have to. My mechanic told me that he would need to replace the shaft support and suggested a poly one in lieu of the rubber one saying it would be a tighter fit and there would not be the amount of movement I have now. He was at 1st hesitant saying it would add to the vibration on the shift handle but now doesn't seem to care about that as much as fixing it as he knows I like everything to be just right.

Is sticking with an OEM support the key for me ? The car has just over 18000miles on it now and he replaced the rotors/pads and rebuilt my calipers for me while it was in the shop. I really don't care about some extra vibration if that is what it will take to correct this.

Thanks guys!

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paulbinct

· #9 · Oct 1, 2007

Dolce86, I will be interested in how this turns out for you. I had motor mounts and tranny mount replaced on my '91. The thumping was reduced but not eliminated. I have not tried to take any more steps to eliminate it yet. Some people h ave suggested that the center busing on the trunnio, whereit attaches to the differential, may need to be replaced, but this is kind of a PITA job from what I understand. Many threads about this topic, with no real consensus. My guess is the center support bearing rubber surround is the issue, like on yours. So keep us up to date!

Dolce86

· #10 · Oct 2, 2007

paulbinct said:
Dolce86, I will be interested in how this turns out for you. I had motor mounts and tranny mount replaced on my '91. The thumping was reduced but not eliminated. I have not tried to take any more steps to eliminate it yet. Some people h ave suggested that the center busing on the trunnio, whereit attaches to the differential, may need to be replaced, but this is kind of a PITA job from what I understand. Many threads about this topic, with no real consensus. My guess is the center support bearing rubber surround is the issue, like on yours. So keep us up to date!

Hi Paul - I don't think I'll be trying this one myself. I have a cramped space to work in and something like this really needs to be up on a lift to work on properly. I'll be running her over to the shop today so they can do what has to be done. I figure it will be a lot easier to write a check vs. my time underneath the car on jacks. It should be done soon and I will respond back and let you know. I agree that it probably is the rubber surround ( original one) and is ready for replacement.

paulbinct

· #11 · Oct 2, 2007

I agree, this is not something I would try to do either. DO you think you will try the poly or regular?

Dolce86

· #12 · Oct 2, 2007

I'm kind of torn at this point after having read some of the other members comments. My guy seems to think that the poly is the way to go to correct this. He told me it was a quicky job-no big deal so I guess I will go with that.

If I am not happy with it I guess I can have him go OEM and swap it out.

I should be able to post back within the next 2 days with a more informed reply.

Dolce86

· #13 · Oct 2, 2007

p.s. Anybody notice the little green (reputation) box has dissappeared

WopJob

· #14 · Oct 2, 2007

Favali said:
I put one in my 93 about 2 years ago....drove it for 1-2 miles and took it out. I installed the factory support. The part still resides in the bottom of my box of spare parts waiting to be mailed to someone who wants it.

It may be good for a race set-up but for the street it did nothing but significantly increase vibration and noise. IMO, a waste of time and money.

I did the same as Favali. We seem to have gotten the same result. a louder than normal vibration noise. Same as you. I removed the internal pieces and kept the side piecen on. this quited the HUMM. but improved shifting because it keeps the tran from going side to side. I was unaware that Favali had already done this.

It's my belief that there is domething wrong with the drivetrain of our cars, hence a tigher bushing makes the "whatever" is wrong obvious with the loug HUMMM and vibration. I believe that when the drivetrain if in excellent shape puttin the powerflex bushing in does not result with the HUMMM. This is only my opinion deducted from my experience and the like that I see on this board.

It has been suggested by another member (name escapes me) that the factory bushings were made "soft" on purpose to hide the fact that spiders came out of the factory with unbalanced drive shafts, and that the soft bushig was a quick fix rather than to fix an old problem. I believe that this posted had a his tongue firmly in his cheek.

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Dolce86

· #15 · Oct 2, 2007

WopJob said:
I did the same as Favali. We seem to have gotten the same result. a louder than normal vibration noise. Same as you. I removed the internal pieces and kept the side piecen on. this quited the HUMM. but improved shifting because it keeps the tran from going side to side. I was unaware that Favali had already done this.

It's my belief that there is domething wrong with the drivetrain of our cars, hence a tigher bushing makes the "whatever" is wrong obvious with the loug HUMMM and vibration. I believe that when the drivetrain if in excellent shape puttin the powerflex bushing in does not result with the HUMMM. This is only my opinion deducted from my experience and the like that I see on this board.

It has been suggested by another member (name escapes me) that the factory bushings were made "soft" on purpose to hide the fact that spiders came out of the factory with unbalanced drive shafts, and that the soft bushig was a quick fix rather than to fix an old problem. I believe that this posted had a his tongue firmly in his cheek.

Tony- did you find the sound/vibration to be extreme ? We all have different levels in which we tolerate things but I just want to get an idea as to what extent the sound level/vibration increased.

Thanx

Dolce86

· #16 · Oct 9, 2007

Hi Paul-

Picked my car up at the shop this afternoon. While she was there, I thought it best to have a new O2 sensor installed ($169) for the part alone. Anyway, he installed the support bushing - it is noticeably louder and overall there is more vibration - even at idle. At dead stop with the clutch in there is less sound and even less when placed in gear. Shifting is a little more precise/tighter than before - 3rd and 5th I notice need to be shifted completely as it did not seem to grab as easily. Once in though, it stayed and I just need to make sure I take the shift through its full range.

The sound level and vibration I can probably live with in the long run, If it will keep my drive shaft from dancing out of 1st gear, it will probably be worth it. Once cruising and if not getting on the pedal too hard, it is fine and really not that bad.

I am curious though, since it is not a big job, what the difference would be if I purchased a new stock one and gave that a try. My Quad just turned 18,000 miles so wear is not due to usage. Rather, most likely due to age and drying.

I had her out tonite for an hour or so. My wife and I ran some errands and it was a great night for the top to be down.

Overall, I really do appreciate the confidence of coming off a dead stop and not hearing the shaft bounce. Let me know Paul if I can share any other information that I might have missed.

Regards

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wyoming_alfa

· #17 · Oct 9, 2007

I installed one on my 85 spider and noticed a huge difference in vibration. makes it sound and feel like the car is working harder than before. It did help everything feel a lot tighter, but next time I jack the car up I'll put the new mount in instead. When I bought the car it had saggy tranny mount and really saggy motor mounts, along with bbroken fan shroud. So I think with all the work I've done on it, I just feel the road a lot more.

mflugel

· #18 · Oct 9, 2007

I just replaced the motor mounts and transmission bushing on my '85. It is a different car. Shifting is precise and it no longer jumps out of reverse. The stock bushing works very well!!!

Dolce86

· #19 · Oct 9, 2007

mflugel said:
I just replaced the motor mounts and transmission bushing on my '85. It is a different car. Shifting is precise and it no longer jumps out of reverse. The stock bushing works very well!!!

Did you have any issues with the drive shaft bumping the tunnel prior to installing the new bushing?

Thanks

BSN05

· #20 · Oct 10, 2007

Dolce86 said:
p.s. Anybody notice the little green (reputation) box has dissappeared

Surely you can guess who's responsible for that.

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