It seems that most are recommending yearly flexplate pre-load checks and you hear tales of frequent needs to re-adjust. Then I think of the thousands of 928s that have likely never been checked, ever. Then one has to wonder how many 928s change hands with some thrust bearing damage?

It just underscores the need for a complete PPI....but this is not a simple matter as thrust bearing checks are not common and they are not something a person can do easily...nor do many sellers want people messing around under their cars with wrenches.

As such, it would seem that TBF must really be quite uncommon in the larger picture....or there are more than a few cars running around "out there" that must have some TB damage.

Jim started this thread with a couple of nightmare situations. It would be a very sad day to find that a car you had just purchased had TBF. That's one reason I'm sticking to 5 speed manuals.

This is unfortunate since the 928 auto trans is a very strong unit.

Just thinking...

H2

 

Why didn't they change to a hydraulic belt tensioner for the GTS in '93, when the 968 got one in '92?

The 'while back' period was before your superclamp, and the query was if someone had tried using two factory clamps.

I have a four post lift now like Bill, and I, ahem, 'relieve the pressure' about once a month. If I had to rebuild the torque tube, I'd probably get one of your clamps.

I hope I don't sound preachy when I have to point out all the ways Jim Bailey is missing the point when he says the factory tensioner has worked well for 25 years?

 

Ken,

Thanks for the clarification! And good point about the 968 belt tensioner.

As far as sounding "preachy" I know I'm one of the biggest violators when it comes to certain TBF issues.

Kind regards,
Constantine

 

Bill,
I followed the change out of the torque tube when the shaft failed. A very interestig thread. I have saved it off onto my files for reference if ever needed.

Constantine,
As stated in some of my previous post, I really like the design of your clamp and I believe that it is the best solution for the problem of migration and possible TBF. I applied loctite a few years ago and no migration and I can spring the flexplate to check end play with dial indicator. I have also checked the aft clamp and checked the torque on Allen Headed lock bolt and in good order and condition.

I have the data sheet for the loctite and decided if and when I have to remove the clamp, out will come my trusty butane blow torch and fire extinguisher.

If and when I have to remove the torque tube, I will purchase one of your clamps and fit it.

Tails 1990 928 S4 Auto

 

What is the overall experience on Loctite 290? I know that some guys used it with good results. I replaced my torque converter bearings in 2005 and installed a rebuilt TT from 928specialists. I glued the flexplate back then with Loctite. No problems ever since, no movement

 

Tails,

Thank you for the kind words! Since you did the TT change out a short time ago I hope you won't have to go back in there for a long while.

Kind regards,
Constantine

 

I have an extra one from the spare engine that I'm willing to loan out to you for testing.

 

Is it a good idea to replace the stock allenbolt in the clamp to common six-point 12,9 bolt instead? What material (stengthnumber) does the stock allenbolt got?

My car is an 32v 86 with auto.


/Tobias

 

the stock allen bolt is a 6 point and its a 12.9 this is about as strong as you will find. Use Blue loctite on the bolt threads and you want to make sure that the bolt you use has the thicker shank. Usually the rear pinch is more loose than the front so make sure to check this bolt as well, you might have to realign the shaft to fit in the rear coupler

 

Dont bash me, we all have a rite to our opinion but this is 5 pages of nonsense my car has 107k on it ,if its gona happen it would of allready,after you make these adjustments for tbf,then drive a block down the road, it goes back to where it originally was when you started,im just guessing on that but like dr.spock says its logical. corn

 

And you had your 928 for how long?
The TBF on the 32V autos is a documented problem.

 

When you make ill informed statements such as this you should be bashed. You are correct in stating that you have a right to an opinion. However, that does not mean that your opinion is right.

My car suffered a TBF at around 149K miles.

 

Hi Wade,

Any details on your TBF. As in "Everything was fine then one day it started to..."

Always a bit interesting to hear about some of the weird sypmtoms and how the final diagnosis was made, if it's not too prying or painful to recount.

Thank you,
Constantine

 

What is the overall experience on Loctite 290? I know that some guys used it with good results. I replaced my torque converter bearings in 2005 and installed a rebuilt TT from 928specialists. I glued the flexplate back then with Loctite. No problems ever since, no movement
__________________
Schocki

I developed the "LOCTITE FIX" about 8 years ago and have never heard of TBF on a car that it has been applied. The only negative that I know of is that you have to use a lot of heat to undo it if you have to remove the driveshaft.

For more info go to http://members.rennlist.com/captearlg/loctitefix.html

 

FWIW my suggestion is to only use the loctite on the bolt threads not the flex plate clamp, adding loctite to this part will add more grip to the splines/shaft.
BUT when its time to remove it, I think that adding heat to break the grip may also damage the clamp, not to mention the need to clean out the splines.. Remember that the driveshaft will be running in the temp range somwhere from ambient to 250 deg ( estimated) this will depend on how long the system is in operation and how long the car is not moving. The cats seem to do a pretty good job of heating the drive line especially when the car is in stop and go driving