Transmission Mount Insert Installed, Mixed Feelings

This past weekend's project consisted of doing the first oil change since acquiring my car (no crunchy bits to be found in the filter!), and installing Powerflex 'street' type urethane transmission mount inserts. Well, not sure how I feel about the "improvement". I think the clutch engagement and shifting might be a little more direct or consistent, but I'm willing to admit to placebo effect. What I can say is that the car is noticeably louder. At times it seems sort of cool, a little like the coarseness of an aircooled 911. Other times it's moderately annoying, like the drone of a diesel charter-boat. I'll give myself 500 miles to see how I come to terms with it.

Quotes source post: 14071993

Is there improvement in the shifter going into gear without any hesitation? Do you have semi solid engine mounts?

^This^ !!! You'll get used to it though. I put the FF Black inserts in mine (got sweet deal...) and was almost shocked on the test drive - I literally thought I screwed something up, but after going through a mental checklist, realized that the transmission was just much more connected to the cockpit than it had been before. The upshot is that you get used to it fairly quickly

Do you need the special tool to press this in? I think the company was out of Southern California that offers the tool... Come to think of it I recall reading about using threaded rod and fender washers to fabricate something to work as well. Just curious. Chris

I think he's talking about these https://www.powerflex.co.uk/road-ser...Kit/12311.html They insert through the transmission mount. Here's the American version http://www.function-first.com/produc...s-mount-insert As you can see, quite a difference in price... - pretty sure they are functionally the same

Ohhh, I get it...thanks Dporto. So, this is sort of like a addition to the stock bushing then...rather than a replacement. What I was watching on various videos was that OE bushing being pressed out and replaced while in this case it is retained and these Function First pieces fit inside. Neat concept I suppose. Will wait to get more opinions and results from VFRMike to see if this is a good idea. Chris

Yes, these are a pair of inserts that fit into the voids of the OEM rubber mount. Didn't require any special tools, but they are a tight fit, I used a big pair of channel-locks against a thin piece of wood to squeeze them in. Effectively gives you a solid rubber/urethane transmission mount. The motor mounts are Rein, OEM style replacements. I never had any trouble engaging gear before hand, but I've been telling myself that the clutch engagement might be a little more linear (with the drivetrain not moving) and the shifting might be a little more precise. Not a big difference though. When I took a spirited run through the mountains (LOVE the San Diego back roads!) the other day, the car felt particularly good accelerating and shifting (but isn't a 911 supposed to?), the NVH during trailing-throttle was disturbing though. I have a new 997 shifter assembly sitting in the garage, as my next project, hopefully I have a more clear-cut opinion on that one afterward. I'll most likely drive it as-is until the next oil change (I DD this car in SoCal, so the miles will go by quickly).

Did you replace old broken transmission mount before trying insert? 997 stock upgrade part. That's the problem -the one sitting in your garage

I'm not sure I understand, there was nothing wrong with my original transmission mount, no tears nor deep cracks. The new 997 shifter is to address the looseness in my 14yr old, 84,00mi original shifter, and to slightly shorten the throws, hopefully without affecting NVH in the cabin.

Your old mount is shot- You'll see that when you replace it- There are other threads on it. Not initially visible. Age- rubber cracked- shot-If you have the new one put it in with insert if I'm reading this right.

Respectfully, I'll pass on that advice. The factory mount was in good shape, so much so that I'm sure the PO must've replaced it at some point. I've seen plenty of torn/cracked/sagging bushings over the years, this wasn't one of them. I was reviewing a similar thread from last year, and someone described the feel as being like a Subaru boxer, I'd agree with that assessment. We'll see how I feel after some more miles...

Regarding the OEM mount discussion above, the GT3 and Turbos use a different style trans mount than the manual transmission Carreras, so you guys are talking about 2 different transmission mounts... The manual transmission Carrera trans mount bushing is pressed into the transmission case. The 996 bushings here are known to sag over time, but their outright failure rate isn't nearly as high as with the GT3/Turbo mount. The GT3/Turbo trans mount can be removed from the car to access the 2 rubber bushings, and the 996 variant of these bushings is more susceptible to failure. (Porsche only manufactures the 997 version now, which is a direct replacement.)

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Read this post a couple times. I can't figure out if you are giving a positive or negative review

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Ha! Perfect - I guess my writing skills are ok then... The review is what it is - it's really a matter of taste/perspective whether it's positive or negative. I guess you could say it's positive in that the inserts did exactly what they were supposed to do (fill the voids and firm up the transmission mount). For some folks the additional NVH might make it a negative... I've gotten used to it and consider it an overall win. I would imagine that the yellow or orange inserts (softer than the black) would be a little more tolerable re: NVH (at least in theory)

Quotes source post: 14078331

Do you have semi solid motor mounts? Which did you install first? I have RSS mounts engine mounts, which made a huge difference. Considering FF inserts.

No, I used the Rein (stock) motor mounts - they made a big difference to, but not in NVH per se'... FWIW, I did them first followed by the tranny inserts...

Quotes source post: 14077401

See, I think that's the point. I haven't yet decided on if it's an improvement or not. In the week I've been driving my car with the inserts, they seem to have 'broken in' a little, but depending upon the revs and throttle position, the feeling/sound ranges from awesome to teeth-grating, and back again. Maybe, just maybe, the engineers at Porsche really knew what they were doing in the first place.

Replace old mount with something is the point. If you put insert in old mount you are waisting your time. New 997 mount with insert fine

Well, I gave it a month. There was definitely some "breaking-in" that occurred, but still too much unpleasant (to me) vibration. I just removed them about an hour ago and took a spin, it's back to the way I like it. They'll be on Craigslist by tomorrow night, if anyone's looking for some lightly used urethane inserts, cheap

I just ordered and received these too....now I need to experiment like you... Chris

Quotes source post: 14071993

I don't understand how a transmission mount insert has caused any kind of drone. ??? Either you are interpreting vibration in a way that I don't quite understand, or something else happened while the transmission mount was going in. Or we need to hear more about what kind of oil was used.

Have you ever stood on the deck of a fishing boat and felt/heard the drone the diesels make as you slog out to sea, doing 6-10 knots? That's what the NVH quality is like on the freeway after installing the transmission mount inserts. I'm not saying the inserts have 'caused a drone', I'm just making an analogy. As for oil? I always use Wolf's Head straight-30, 'cause my grandpappy said it was best.