Clutch Install Issues, Pressure plate not in contact with flywheel Options

[RKramden]

I am having issues with my new clutch. After tightening to torque (18fp) the pressure plate is still not in contact with the flywheel (aprox. 1mm gap). Is this normal? If not, should I continue to tighten until it bottoms on the flywheel?
When I first installed, it was almost a 1/4" gap at torque, so I put some clamps on it and I got the internals of the pressure plate to move that I now assume were somehow frozen. Any advice would be greatly appreciated.

[Shivers]

18 lbs is right. I wouldn’t go any more. If it was me, I’d pull it apart and see what is wrong. Are those bolts too long? @RKramden

[ndfrigi]

Yes probably you have a longer bolts and I think not allen type.

[Superhawk996]

If it was me, I’d pull it apart and see what is wrong. Are those bolts too long?

(IMG:style_emoticons/default/agree.gif) Something is wrong

Those fasteners are not correct and may be too long.

Supposed to be M8x15mm long hex head bolt and they get a lock washer under the bolt head which will be 2 or 3 mm thick so only about 12 - 13 mm of actual thread into the flywheel. The depth of the pressure plate fastener holes decrease when the flywheel is machined.

A socket head cap screw is the wrong fastener for this application. Although they have higher tensile strength, they are more brittle than a hex head bolt due to case hardening. Even worse, it looks like you are using plated socket head cap screws which are prone to hydrogen embrittlement making unexpected stress cracking a real concern. Stick with the OE style hex head bolt as the proper fastener.

More details than you wanted to know:
https://www.boltscience.com/pages/the-stron...r-fasteners.pdf

Also if flywheel was machined, that needs to be inspected carefully along with the dowel pins to make sure the pressure plate isn’t hanging up on something. Likewise step height between friction surface and pressure plate surface needs to have been machined properly

[burton73]

Picture of bolts

Bob B

[RKramden]

I will change the bolts once I get the tightening to the flywheel issue resolved. They currently do not bottom out or hit the case. Thanks to Glen at Pelican for cross checking the Sachs part #s.
Tomorrow I will take the pressure plate to the machine shop to put on the press to see if there is enough flex to to actually compress down to the flywheel Thanks all for your input….

[Shivers]

I do not have a flywheel to look at, it is on the car. But I remember the holes going through, but I do not remember the threads going all the way to the back side. I looked at an image, that I could not post here and it does not look like there are threads in the holes on the back side. Does anyone have access to check either way?

[RKramden]

Issue resolved with hex head bolts (fully threaded). The Allen bolts had a shoulder that was just long enough to stop at the flywheel without snugging up the pressure plate all the way. It never crossed my mind that it was a bolt issue as they came with the flywheel.
BTW the pressure plate attachment points are not threaded all the way through. The backside (curved portion) is drilled out bigger than the bolt.

[Superhawk996]

(IMG:style_emoticons/default/smilie_pokal.gif) good find

So which supplier did the flywheel come from with inappropriate fasteners ? Please help others to avoid the same issue.

[RKramden]

The flywheel came via a third party so I’m not sure when the bolts got added to the mix or if they grabbed the wrong bag at the shop. The flywheel came from KEP and it is a work of art. They were very helpful trying to sort out my issue even before I found the KEP mark. Looking on line there are many pressure plate bolts that are both Allen head and not threaded all the way to the head that must work for some transmissions, just not a 901.
Thank you all for the comments and suggestions
On to the project!