marine928

In 2013, one of the many upgrades I did to my 87 was the installation of Constantine's SUPER CLAMP and TT Bearings. Today I decided to do a few checks on her including the Flex plate and rear pinch bolt. ( had never checked rear before). After 10 years and 51k miles, here are the results...

Rear pinch bolt access

The original bolt was in perfect condition. I did order a replacement from Roger just in case there was some stretch.

Flex plate and SUPER CLAMP

Perfect, no warping at all. Not bad for 10 years and some pretty spirited driving.

No migration at all. Constantine's SUPER CLAMP is the real deal!!

khalloudy

I see lots of surface corrosion. Is the Super Clamp not galvanized? I am thinking of installing it on both my S4 and GT. If it is not galvanized, maybe it is better to have it processed before install.

marine928

Khaled, not sure. It's been operating flawlessly for 10 years in the hot, humid and salt air environment here on the Gulf Coast. The little bit of rust is just on the surface and could be easily removed. Coating is an option. You might also think of upgrading your TT with his bearings. The combination pretty much alleviates the TT/flex plate issue.
The heat such as you have in KSA will deteriorate the original rubber in the TT.
بارك الله فيكم وفي أسرتكم بالتوفيق والصحة الجيدة والأمان والسعادة
Lon Davis
Kingwood, TX

Mrmerlin

Umm are you going on a picture of the splines and the flex plate?

The real test is to see if the flywheel is preloaded.

Please use a prybar and see if the flywheel clunks back and forth.
If the flywheel wont move then its preloaded.

NOTE a correct inspection/ check of the drive shaft/ flex plate MUST include,
checking for flywheel freeplay and the rear pinch bolt must be checked and torqued to 66 ft/lbs,
add a drop of blue thread lock so the bolt wont fall out.

NOTE from the picture,
That rear pinch bolt head has what looks like a damaged tool surface,
possibly from the tool slipping free.
if so this bolt should be replaced,
and the tightening tool that caused it replaced.

Only use Hi quality allen tools to torque these bolts as head damage can occur.
Pressing the tool hard into the bolt head while torquing

Lastly I would use a scotchbrite pad and clean off the corrosion,
then smear some DC111 on everything that had corrosion including that little nick in the driveshaft.
this will prevent water from getting through to the surface and essentially stop any further damage.

marine928

Mmerlin, Wouldn't the straightedge indicate a load ? Also the rear pinch bolts condition seemed to indicate no movement as well. It was last removed in 2013 when I dropped the driveshaft to upgrade the TT and clamp. I did order a new bolt from Roger and will also take care of the surface rust as suggested.
Lon

Mrmerlin

Lon, No that is not a valid test, it might still move but could be preloaded.

You need to see if the flywheel is free to move.

if not pry it back then retighten the front clamp.

NOTE Tighten the rear pinch bolt first before you retighten the front.

NOTE your bolt picture makes it look like the socket head has been damaged,
if so then follow previous instructions
NOTE when removing the rear pinch pay attention to how tight it is ,
as most of them are loose,

NOTE once you get the drive line on a service schedule,
then you can monitor how its performing.

marine928

Hmmm, I hate the idea of taking as ll the bolts loose on the Super Clamp but will consider it as due diligence. What is "preload" in this context?

Black Sea RD

Lon,

If you do not see any movement of the front union between the clamp and drive shaft from when you first installed the Super Clamp, no bowing of the front flex plate as shown and the rear pinch bolt came out easily, you should be fine.

There has been an ongoing debate about the root cause of TBF between slippage at the front drive shaft and clamp union, or slippage at the rear pinch bolt.

Don't want a re-hash here and the decision is yours.

Would take care of the corrosion as suggested and as we discussed earlier by PM.

HTH,
Constantine

Black Sea RD

Mods,

Don't know why my User name has reverted back to my sponsorship days.

Full disclosure that I am no longer a Rennlist sponsor but am considering stepping back into this position since it seems the boards have been cleaned up a bit.

Please let me know what I need to do to rectify this situation.

Thank you,
Constantine

FredR

You will have quite some fun trying to fit a Superclamp on a GT! 🥴 It is for automatics only.

The rust is nothing of any consequence other than cosmetic. A wire brush and a rust preventive spray will easily take care of that. When iron rusts it forms ferrous oxide that increases the volume by a factor of six or so and thus looks consequential when in fact it is irrelevant. Had to deal with a problem like this on our gas hob recently. The fascia is stainless but dumb *** engineers at Bosch made the inner rib out of galvanised steel-the stuff corroded and jacked up the hob due to the swell. Took out the rust, passivated the good surface underneath and it looks like new again.

marine928

Hi Fred,
I agree with you on the minimal rust on the clamp. It is a very robust piece of hardware and since I have the cover off I will address it anyway. I do the same thing for every nut and bolt I remove. They get cleaned by wire brush, WD 40 and anti seize whenever applicable. The previous owner was an ISO inspector and very particular about taking care of the smallest details also. Even the muffler bolts get the same treatment. I have never had an issue with removing any nut or bolt.

Lon

khalloudy

Hi buddy, nice to hear from you!

i thought that the super clamp would fit on either torque tubes and flex plates... I got the S4 to the US but unfortunately had to cut my vacation short due to a family situation and return to the middle east on a moment notice. It is sitting next to the GT for now, and both are slated for some work but it will have to wait for a moment until i get things squared up here.

P.S. I hate rust!!!! I guess seeing french and Italian cars rust to dust in the 80s left a mental block there. Galvanizing any part going on the car, specially on the outside/underside is a must for longevity - even if just cosmetic.

Mrmerlin

LON I am not suggesting that you first loosen the front clamp to check the flywheel free play.

All you need is a pry bar to gently move the flywheel front to back to see where it is.
if its preloaded,
you may be able to push the driveshaft back with the rear pinch bolt removed so you wont have to loosen the front clamp.
If it moves easily in both directions and not favoring preloaded against the thrust bearing then leave it alone.

marine928

Mmerlin,
O I C, that makes more sense. I will test that out this afternoon. Should I put a dial gauge on it ?
Lon

marine928

Khaled.
Yes, rust has been the demise of many great cars. I too had to cut a vacation short this year due to an unexpected family situation. Was sitting on a beach in Kona, Hawaii when I got the call. Getting a last minuet hop to the ME and the US mainland can be a real pita sometimes.
Hard to believe that the corrosive air we breath can cause so much damage to unprotected metal and does not harm us.
I would like to hear the back story on both of your cars sometimes. Always cool to hear how we find our cars...
Lon