David L. Lutz

I checked again my Flexplate preload and crank endplay. I found my Flexpate to be bowed 3.5mm and my Crank endplay measured between .008 & .009 consistently. (paused and gave thanks to the power above)

When I released the clamp bolt, my Flexplate moved maybe 1mm back, but still had over 2mm of bow. I made sure the clamp was loose and went in behind the flywheel with a pry bar and flexed the plate to the rear watching the clamp move along the shaft but the flex plate didn't want to spring back into its orginal flat state. After prying and flexing the plate, I did get it to return within 1mm of bow.

My questions are;

1. Should I force the plexplate to the level or straight postion when checking with my stright edge and tighten the clamp (which holds it in the straight position) or just leave the plate in its natural state with the 1mm of bow?
2. What determines when you need to replace the flex plate? (not the clamp)

Thanks in advance for your help.

ROG100

Good Questions and you will probably get a number of answers.

I leave the flex plate in its natural position bearing in mind that it is now going to be checked every year.

Any cars that need TT or Gearbox work will be fitted with the "Constantine Clamp" so that this is no longer an issue.

Schocki

When you release the pressure and it still shows some bowing, I would leave it like this. Just make sure that you use the prybar behind the flywheel to pull the crank "out of the block".

I think that the bowing you see is probably metal fatique on the flexplate. The flexplate is simply made out of to pieces of metal and is bolted together. That's where the spring tension on the plate comes from. You could try to losen the 6 bolts that hold the flexplate on the flywhell slightly, to allow for a little more movement of the 2 plates.

Roger is right. Check the flexplate at least once a year, if everything is still stock. My flexplate was glued with Loctite 230 in 2004 and has not moved since. I drove the car in Texas everyday and now in Germany and it sees speed in excess of 120 MPH on a regular basis, still no movement.
If I would have to replace my TT I would also go with the Constantine Clamp. That baby puts so much pressure on the TT shaft that there is no movement, guaranteed but it is not cheap.

David L. Lutz

Thanks for the quick response. I have read most of your previous postings and am aware of the "Constanine Clamp".
I am planning a TT rebuild in the very near future and would like to purchase the clamp now. Please advise where.
Roger, I checked your web site and didn't see the clamp?

Constantine, I will revisit the clamp and clean it but I have flexed the plate from the back side maybe 15 or 20 times and the clamp seems to move freely. With pressure the plate does straighten out, but when I remove the pressure (pushing from the front of the flywheel, my bar is pressing on the opposite side of the flex plate from the "clamp") the plate regresses to the slightly bowed state, 1mm or so. If I leave it as it is the flex plate will be bowed. Maybe I should just keep flexing it until it bends back to normal if the cleaning does not help.

Thanks

David L. Lutz

Schocki,

I agree it must be fatigue and it is just a little "sprung" .

I will still clean the shaft make sure it can move back into place freely, pry the flywheel so the crank is to the rear of the block and torque to spec.

I will for sure go with the new clamp during the TT rebuild.

Thanks

ROG100

Hi David,
Sorry I don't keep the info on my web site - just tooooo busy to update the info.
I am expecting delivery of another 10 clamps shortly so will be able to supply it very soon.
Email me at Roger@928sRus.com for more info.
Thanks,
Roger

Schocki

Got my rebuilt TT from 928Intl $500 plus core charge. Decided to replace while I replaced the torque converter bearings. No issues whatsoever since 2004

borland

I second what Schocki said about loosen and retightening the outer flex plate bolts. That should allow the flex plate to spring back flat.

I'm in favor of not using any solvents on the shaft, as residual coating of grease eliminates the changes of corrosion.

ROG100

You could also buy a TT from 928sRus for $495 plus core charge and shipping. 8>)

Schocki

Hey Roger,
to my defense: This was before 928sRus

Cheers

fabric

What I've read (and done myself) is that after you loosen the clamp bolt, give the engine 2 revolutions via the crank bolt. WHen I've done this, the flexplate has returned to near as I can tell is flat. I'm going with the loctite trick this next time - Earl Gillstrom recommends loctite 290, which is a penetrating formula so it will "get in there" a bit better.

David L. Lutz

Chris, I did turn it 1 rev. with the crank, I will try a couple more.
If that doesn't do it I will loosen the bolts and see if that helps.
Thanks to all for the help.

IcemanG17

Your endplay #'s are well within spec...so your good to go!! .008-9 is between .20-.22mm well within the wear spec of .4mm (if I remember correctly).... I would worry about the bowed plate....once you release tension on it and it springs back to "neutral" even if its bowed there is no load on the thrust bearing....so your fine....drive on and enjoy!!