Torque tube bearings worn?
#16
Former Vendor
Rivets were used until end of 928 production.
Flexplate rivets being loose is extraordinarily rare. People send me their flexplates to be repaired (the factory bolting repair is a poor solution) and I still only do a couple a year. The technical bulletin about the rivet problem is from 1985 and I would guess (hope) that Porsche had their supplier correct the problem, back then. I wouldn't take a 1991 car apart, assuming this would be the problem.
I just had a 1989 car with 48,000 original miles that had the internal damper in the torque tube hitting the rear coupler, from the rubbers being completely disintegrated....I'd look through the rear hole, in the torque tube, which is used to tighten the coupler and see if the damper has moved.
While you are there, check the torque on the flexplate coupler and the flexplate to the converter hardware.
Last edited by GregBBRD; 05-14-2018 at 01:50 PM.
#17
To Stratford Shark,
Tracy's post brings up a great point about another problem that can surface with the bolts that attach the rear flex plate to the TC. These can easily be checked with everything still in place by removing the rubber plugs on the torque converter housing and checking them for correct tightness.
Something to do before committing to dropping the trans.
Tracy's post brings up a great point about another problem that can surface with the bolts that attach the rear flex plate to the TC. These can easily be checked with everything still in place by removing the rubber plugs on the torque converter housing and checking them for correct tightness.
Something to do before committing to dropping the trans.
#18
Drifting
Thread Starter
To Stratford Shark,
Tracy's post brings up a great point about another problem that can surface with the bolts that attach the rear flex plate to the TC. These can easily be checked with everything still in place by removing the rubber plugs on the torque converter housing and checking them for correct tightness.
Something to do before committing to dropping the trans.
Tracy's post brings up a great point about another problem that can surface with the bolts that attach the rear flex plate to the TC. These can easily be checked with everything still in place by removing the rubber plugs on the torque converter housing and checking them for correct tightness.
Something to do before committing to dropping the trans.
Since the TT can be removed with transcand suspension in place, what would prevent me removing torque tube, and then unbolting TC cover with flexplate?
#19
Former Vendor
And anyone that would do this to a 928 should have their tools taken away! Whenever I see this "hack job" done on a 928, I replace the bell housing, if things are apart enough to do this. If I don't replace the bell housing, I make notes to do so, in the future.
If I see this during a PPI, I will instantly reject the car, with the assumption that whoever worked on the car was such a butcher that the rest of the car will have been done, the same way.
There's no excuse for anyone to be this lazy!
#20
Drifting
Thread Starter
I could never bring myself to butcher a 928 either! But here’s a write-up (Bill Ball’s I think) where he explains how to access top bell housing bolts and remove the housing:
http://billsworkshop.com/P928S4/TT/torquetube.htm
http://billsworkshop.com/P928S4/TT/torquetube.htm
#21
Rennlist Member
I guess I better add another thing to the list of things to do while the engine in my 81 is out...
I'm also curious, has anyone made a replacement or refurbished a stock vibration damper for the torque tubes? Seems like they are really needed at the age our cars are.
I'm also curious, has anyone made a replacement or refurbished a stock vibration damper for the torque tubes? Seems like they are really needed at the age our cars are.
#22
Rennlist Member
I've never cut one myself but seen more than a few that have been cut, no one ever noticed any difference, not that I'm supporting it, just saying.
As per the cutting part, it's the exact same piece that is removed by the factory and replaced by the "Guide Tube" on a manual trans car.
So one could drill and tap the upper bell and install a strap w/two 10mm bolts if it were bugging them that it was missing, right?
Dave K
As per the cutting part, it's the exact same piece that is removed by the factory and replaced by the "Guide Tube" on a manual trans car.
So one could drill and tap the upper bell and install a strap w/two 10mm bolts if it were bugging them that it was missing, right?
Dave K