AO

Mr. C...

I would never call you old, I'd call you "Old Timer" then run for the hills.

blown 87

You may be a lot of things Andrew, but shy is not one of them.

Mrmerlin

Porken why dont you design a system thats affordable, to clamp onto the front of the engine that will let you pry the crank fore and aft and see if it has a preload and be able to measure the distance??. This is easier to do than pulling the bell housing.
Once the check has been done then it could be monitored from the front top of the engine.
If the crank wont stay at its rearward position but springs forward or it cant be pushed back then the bell cover has to be removed

TheClairvoyant

I am glad I stumbled upon this information. I could have not known about any of this stuff and not had a care in the world (at least when it comes to the car) and wound up with a catastrophic failure down the road and wondered WTF, I thought I kept up on my maintenance?!?!

I don't do my own work, although I have been thinking about learning. These cars are very expensive to maintain, and I'm not rich. With the help of people on this forum and some people I know who do have pretty extensive mechanical experience, I think I could do at least the small stuff myself. For the time being, I'll be sticking with my mechanic. They've been pretty good over the past 14 years and I've only had one issue where I think I've paid for the 928 learning curve. Otherwise, they've been very attentive and thorough. I'll definitely be calling tomorrow to make an appointment. I'll also order the PKlamp.

I've read about Constantine's super clamp. That's what I'd really like to go for, but I understand that's a lot of labor. I guess that will wait until I have to have a big job done in that area.

I don't beat on the car very hard. A few high speed runs and some hard acceleration now and then, but most of my driving is fairly tame. Not an awful lot in the way of hard downshifting and engine breaking. The car was purchased with 32K miles and has seen periods of frequent use as well as periods where it hasn't been driven much. Lately, I've been driving it a lot. I'm kinda bummed that I won't be driving until I get this checked out, but I sure beats getting a new engine...unless of course I convince my wife that new 450HP supercharged engine is a necessity

Thanks again to everyone who has responded and everyone who has posted in general. There is a wealth of information on here.

I'm sure my wife wouldn't like to thank you. All she's heard about for the past month is "928 this and 928 that". She was saying my two year old son will probably saying "thrust bearing failure" any day now!

Garth S

If you can handle a hacksaw blade, I can link you to my old threads that show you how to lop off the back 2 of the 6 M8 bolts holding on the lower bell housing cover. Once that is done, it is literally a 5 min. job to release the flexplate tension.
I routinely monitor flexplate migration on three S4 autos for local guys: one of which I 'glued' in place 3 or more years ago has not moved a tenth of a mm in over 20K Km. Two others only move modestly on annual inspections: for your stated driving style, I would simply release the tension and periodically do the 15 min check.
Yes, I think Constantines (collet) clamp is one of the developments that rival the invention of sliced bread ..... but you are able to eliminate your anxiety ( and residual flexplate tension) with no more than simple hand tools - and be ready with a long term TBF prevention therapy to care for your keeper.

Mrmerlin

well its not really a 5 minute job if its the first time your checking the flex plate.
Reason being that the rear pinch bolt should (must) be checked.
i have found many rear bolts merely just past snugged. If the rear bolt is loose then the drive shaft will still be able to move more than it should.
To get to the rear pinch bolt the exhaust system must be dropped and then the center heat shield must be removed,.
There is a rubber plug at the bottom of the rear of the TT .
If you have a helper to turn the engine with a 27mm deep socket you can watch the clamp turn till the bolt head is in view its an (8mm allen).
Release the front bolt first , then remove the rear bolt and check it for damage, if it was loose there is a good chance that the drive shaft will have been grinding away at its shank, if this is so then the bolt should be replaced.
Center the drive shaft in the rear input shaft ande then fit the bolt to the clamp you can use the front clamp to tap on after you tighten it if you need to move the drive shaft.
Fit the bolt with some blue loctite and torque to 66ft/lb.
Pry the flywheel back then tighten the front clamp ( this is done after you measure the crank end play)

TheClairvoyant

I'm definitely having it checked by somebody who knows their way around cars.

I've changed oil in a Buick once, changed tires, and replaced some light bulbs (including the 928), but I'm not going to risk screwing up something important at this point. I've never risked engine block destruction by changing a light bulb

Stephen Porter

Not to go too far OT, but would the value of installing a "Superclamp" justify doing it if you don't need to rebuild the torque tube (already done)?

GlennD

I was soooooo happy in my ignorance. However, since coming to this site, I am now afraid to even start my car.
Let's recap the last two weeks .....
1) fire (man, I feel for that person ... I could not imagine)
2) headlight actuator rod into the radiator
3) flex plate with possibility of chewed-up bearings
4) radiator failing (side covers cracking)
5) cars limping or getting towed home during a pleasure drive
6) etc.

I just finished doing all sorts of work (proudly 100% original - except for the RMB) and now afraid to start it. I am not aware of the PO ever having the flex plate checked. I know that I did not (tomorrow now - if I get sleep from worrying about it).

How does anyone enjoy these cars given all the surprises that keep getting written up here?

In all honesty - I really appreciate all the great tips I have gleamed during my short time here.

Cheers

Mrmerlin

Its OK just throw in the towel and sell your ride , I would bet someone will take good care of it for you

blown 87

A TT rebuild and a Superclamp was the second thing I did to my car.

I am not on the fence about this one, pull the trans and TT reseal the trans, replace the bearings in the TT and put a super clamp in it.

IF the thrust bearing is still in spec.
This one was still in spec at .011 IIRC, and it is worn.


The OP has had this car a long time and loves it, if the thrust bearing goes, it is done for the most part unless he is willing to spend big bucks.

TBF is something to be afraid of IMHO.

For what it is worth.
Greg

AO

Another reason to own a 5-speed.... :happywhistle:

GlennD

I really appreciate the picture of the bearing. Helps visualize

Question:
If the flex plate is checked and it appears that there was pressure on the bearings, there is some small things in the oil that reflect light ... and the bearing is found to be worn, can it easily be replaced or is that it for the engine?

I am not sure of what makes the engine junk on the thrust bearing. When would one consider the engine junk?

Thanks in advance,

ShawnSmith

So happy there's a superclamp slightly aft of my (ever ongoing project) motor

Black Sea RD

Hi Glenn,

Good questions.

Many feel that if the thrust bearing measurement comes within specs, you stop the forward flexplate pressure from recurring and your engine runs and idles normally even for extended periods, then you'll be good to go. Replace the oil and filter and keep checking for forward pressure on the front flexplate at regular intervals, like every oil change or three thousand miles.

If the thrust bearing measurement is not within specs, then you might have a engine block problem already. Some have been able to repair the block if it's not too bad, but sometimes it can't be fixed and a new block needs to be sourced. At this point the crank is usually damaged too. Either way the engine should be pulled, torn down and gone through to determine the health of the block, crank and the engine's rebuild quality.

HTH,