gomez123

I read Dwane's (sp) write up and watched Fred's video. Why do they drain the trans when dropping the rear axle and trans? Is it necessary?

Thank's Guy's

ammonman

I don't know about "necessary" but some auto trans fluid drainage is inevitable when you disconnect the cooler lines from the trans. How much would drain out? Try it and see.

Mike

gomez123

I can't see using a oil can to fill the trans when it's reinstalled. My hand would cramp up and fall off! I could plug off or clamp off the lines. Just preparing for the big job in the next couple of weeks.

davek9

When doing the TT bearings on an Auto, you need to consider replacing the Torque Converter seal and bearing too, and that could get messy if its all filed w/ fluid.
It is not at difficult to drain the TQ and Trans and refill especially if you pump it in via the Factory check valve or the cap on the tank using a pump w/ a hooked hose end.

worf928

And, not withstanding the mess on the floor, if you are doing the bearings you might as well be doing a 'scheduled service' which includes new fluid and filter (and possibly the B2? or B3? (I forget) spring.)

hacker-pschorr

+1
Using a $10 hand pump in the bottle connected to the fill port, filling these transmissions is a piece of cake.

gomez123

Thank's guy's I concur. Transmission service filter etc... Bearings will be replaced. By the way , why are torque converter bearings 47 dollars????

dr bob

Biggest surprise with not draining the trans comes when you are jockeying it around after the cooler lines are removed. Two open ports, add gravity, stir well... Voila!

You can use 14mm-2.00 bolts to replace the banjo bolts and plug the holes in the transmission if you don't want to do the full service. Add a little bit of thread sealer on the bolts to keep everything inside. The cooler lines will still drain so be ready for them with a couple ziplock bags and cable ties. With the TT out, you'll want to service the rubber sections of the lines, plus you'll replace the rubber sections of vacuum hose at either end of the hard line that's attached to the TT.

GregBBRD

Because people are not smart enough to get them from their local bearing supply hose for $16.26 each they order them from Porsche?

The Forgotten On

TT bearings are SKF #6006 2Z C3 HT51 and TC bearings are SKF #6008 2Z C3 HT51 IIRC. They cost around $10 a piece.

You can get some more info here: http://jenniskens.livedsl.nl/Technic...2/MyTip217.htm and make an educated decision.

Constantine

The TT Bearings have a C5 ball bearing to race clearance designator, not a C3 which is a tighter fit.

When in the middle of our own R&D, we contacted the SKF engineers and they surmised Porsche chose the C5 loose clearance since it would allow the relatively small ball bearings to grow a bit with heat under operation and not run the risk of dragging against the race prolonging their life.

The Porsche spec TC bearings are also a bit out of the ordinary according to the SKF engineers, but it might have been due to old ball bearing tech in the day when Porsche first designed the 928.

gomez123

What do you think about *** 2008 sealed with rubber on both sides. That's what I have for my rebuild this winter.

dr bob

Any thought to adding a layer of thermal barrier to the torque tube? The one with foil/mylar reflective faces over an insulation layer? Maybe a protective layer of Heavy Duty Reynolds Wrap over the whole thing, with foil tape on the seams.

Maybe a couple more NACA ducts to push a little more air along the torque tube walls above the heat shields and all.

gomez123

Is the TT that heat sensitive?

Constantine

Heat soak from both the engine and transmission is also at play, besides the obvious heat soak from the exhaust directly underneath the TT.

Would agree with a bit more airflow over the TT assembly if possible, but don't know if that would help to extend the life of the TT assembly significantly.