hb4

Thanks, Stan. Forgot to mention that we did roll the driveshaft on a flat surface and there's no discernible wow. Tomorrow is TT cleaning and bearing installation.

Asiandude

Replaced the two bearing units and dampener with three Constantine bearings last year on my S4 auto, no vibes at all. Don't forget to replace the TC bearings as well if you haven't already (and the trans pump o ring and TC seal and so on and so on........!)
Joe.

Landseer

This thread is awesome. Clear the room for the victory dance.

Landseer

This thread is awesome. Clear the room for the victory dance.

hb4

Wow, doubly awesome!

Pressed in the Constantine bearings yesterday:



Tried the 'hammer them in using the MDF plug' method and managed to destroy the plug in three swats, so resorted to the allthread/plumbing fitting apparatus used for disassembly. Went smooth as silk, but lots of cranking.

Once the bearings were in and positioned per the instructions, the driveshaft slipped in by hand. When it was fully captured by all three bearings, it was possible to move the driveshaft in and out with a firm grip and butt-assisted yank. Hope that's tight enough; the instructions implied that it would be a tighter fit.

Set the location at 2mm past the Trans end with a square, some feeler gauges, and a dead blow hammer. Then I lifted it up on stands and started the TT installation process. Getting it into position, the driveshaft moved back a ways, so I figure I'll reset it at 2mm once it's in the spline at the engine end and fastened to the flywheel cover.

Rob Edwards

Constantine has spoken so this is superfluous, but FWIW, 3 stock bearing carriers + the stock damper weighs 4520 grams, while 3 steel Superbearings are 4600 grams. Clearly aimed to match the weight being put back into the TT.


Also FWIW, a damper alone is 3616 grams.

hb4

My '89 Auto with a brand new factory TT installed in 2002 by the PO had two bearing carriers and one damper. The damper was placed about 4" from the Trans end rather than ~12" back per others' measurements. Photos in Vilhuer's thread show a similar arrangement.

So, the two carriers and a damper that I started with would be 4218g (4520 less 1/3 of (4250-3616). I have installed three 'C' bearings at 4600g per above. Three 'C' bearings and a damper would be 8216g.

Academic question to the vibration savants from the vibrationally challenged....
Does adding 3616g to the TT assembly affect potential vibrations one way or the other? Which way and how much and why? And more or less than the same weight supported by rubber and allowed to sling about as the TT vibrates? Do the frequency and angle numbers written on some dampers shown in Vilhuer's thread give a clue?

Black Sea RD

Hi Bill,

From our research into this whole area during our R&D work for the Super Bearings, the bottom line is that adding weight to the drive line in key areas dampens felt vibrations caused by engine harmonics. Suspending the driveline in rubber (engine and transmission mounts) also further isolates these harmonic vibrations.

The real trick is to add just enough weight to cancel most if not all the vibrations from the passenger compartment. That has already been figured out by Porsche in the form of the vibe dampeners they started adding to the TT as the 928 was further developed.

We decided to not only add this weight in our Super Bearing design, but also add another layer of isolating rubber to this equation in the form of our rubber surrounds of the Super Bearings and our bearing insert which further help to isolate the drive line vibrations from the cabin. Our design seems to work very well and even our reduced weight Super Bearings made from aluminum worked very well in isolating the drive line vibrations.

I am a bit anxious about your results since it is questionable if your vibration problems were really from your old TT. This was a point we discussed over the phone and I truly hope our products help your situation.

Best regards,

hb4

Well the TT's back in the car, waiting for the trans and suspension and the next phase is trying to figure out why replacing the seals in a non-leaking auto transmission caused it to leak.

The first time, we replaced the main TC seal, Primary Pump O-ring, and the large L-shaped seal (boot per PET). We re-used the old PP gasket and were unable to fit the small boot without damaging it, so re-used the old one. We've since acquired a press and will install a new small boot and PP gasket as well as the TC seal, O-ring, and large boot.

The leak was out of the TC opening towards the trans and diminished after driving a few miles to a few drops that did not reach the ground after a 50 mi. drive.

We drained the trans again yesterday, placed it on end, and removed the TC vertically. We then lowered it to a slight incline and took the photos below.

From the fluid trail, it seems like it is coming from the main TC seal. It does not appear to be damaged, so it seems like the only way it would leak is if the TC throat is the wrong diameter, which the rebuilder assures me is not the case. He said it is 1.696" +/- .003".

Comments on what might have caused this leak are appreciated.

Mrmerlin

the seal looks damaged at the 2 O clock position.
make sure to put some vaseline on the bronze bushing just behind the seal so the torque converer snout wont seize on the bushing

Bill Ball

I see what Stan sees too. Recheck that and replace the seal if that is not an artifact. And be sure the spring in the seal did not get displaced. I don't see it in the photo, so it is likely OK, but that can be a problem. The key for me to fixing that seal without causing a new leak was having the tranny essentially standing vertical on its tail so the TC dropped straight down without any possible diplacement of the seal. And everything was lubed well with Vaseline.

And I understand the primary pump o-ring is very easy to screw up and it's not visible for inspection. I ended up swapping in a used primary pump w/o replacing the o-ring, so I avoided that potential pitfall.

Tracking drips in the TC area is difficult. The fluid is so thin that drips from, say, the top of the pump o-ring may not be visible while drips from the main shaft seal will wet the lower o-ring area. I suppose if the main seal area is wet and the top of the pump shows no wetness at all from there down to the main seal area, then blame the main seal, especially if that 2 o'clock defect is real.

hb4

Thanks Bill, Stan.
That item at 2:00 is a little piece of debris that I was able to pick off and wipe on a towel; like a short fiber.

This seal has about two hours duty, but I have a new one that I'll use. When I slip the new seal over the TC throat, it moves freely with just a slight drag. Does this make sense?

When we installed the TC the first time, we slathered it with Vaseline. Would this cause a leak until the Vaseline washed off the seal? The leak acted like it was self-correcting; each time we ran the engine to fill the trans there was less fluid at the TC opening, until after the 50 mi run it was just a few drops hanging there.

supercedar

Bill,

I wonder if the first TC (incorrect one) could have damaged the seal. I finally got out there this morning and took a quick peek and see you have made quite the progress. I will have a look at the new seal fitment on the TC throat this afternoon and report back. This slight leak we are tracking is very minor compared to the puddles it left on the start up/filling process. Any thoughts on what could have needed this time to seal itself?
Thomas

Bill Ball

Well...

My recollection is the seal was pretty snug. I can't find the old TC at the moment to measure the snout, but I don't know how you would get that wrong. I can't see the Vaseline preventing the seal from setting. I missed that you had the wrong TC. If you have a new seal, put it in. I'm sure each time you install the TC you are getting better at it, so there should be little risk to redoing it.

atb

Hey Bill (VV),

How about a pic of the TC output shaft.