atb

My OB track car has always had a crunchy gear box. Would not go into reverse or first without serious grindage, would not take downshift at speed on the track without serious grindage unless you had a perfect rev match, basically wrote it off as another worn out OB tranny.
Just finished the install of the 4.7L and figured I'd follow Kibort's mod of permanently setting the intermediate plate. Kibort uses dowel pins,but Colin does the same mod with tack welds. Ken Osage was kind enough to handle the welding duties. Basically, he set in the appropriate feeler gauge into the adjusters, tacked the adjuster, then removed the feeler gauges.
Today, fired up the 4.7L for the first time, the car easily clicked into reverse and first like a brand new tranny. It is impossible to believe this is the same tranny as what has always been in the car. I can't help but believe there are so many double disc clutch owners that are needlessly living in frustration when this easy fix is available.
This truly works.

BC

The adjustment PRIOR to pinning - how was this accomplished?

Mrmerlin

the adjustment procedure is in the WSM with pictures,
it might be a little easier to understand if you REF the WSM

IcemanG17

NICE...this is good to know......

Fabio421

I am very interested in reading more. I have a crunchy gearbox that I was planning on changing. Please elaborate.

Tom. M

So ...that makes Adams track car, Colins car, and Seans car (the first one we welded up after having years of issues with the int. plate). Lots easier than drilling and pinning..fearing that the pins would come out..

I might just have to re-think my aversion to the double disk setup for my track car. Since I'm running MS..I can run any flywheel (we have a 79 sitting at the shop)...that would be a ton of weight savings between the flywheel and clutch setup....hmmmm.....

So, can a later model release arm be used for the double disk?

BC

Obviously. I am talking about prior to welding but AFTER driving the car. On a really bad plate, it moves around.

atb

Basically, the intermediate plate has a factory spec for where to have the "H" adjusters set after installation. I was skeptical doing this mod on an OB intermediate plate, because the spec and overall adjustment range is so much smaller on these earlier clutches than on the later dual disc intermediate plate. Given how little adjustment room there is, especially in the older clutches, I personally didn't think it would, or could, make a very big difference in how the clutch performed. Like I mentioned in the original post, I really thought it was a gear box problem. My clutch didn't drag, and actuation / engagement has always been good. Up shifting 1st to 2nd has always been notchy, but the rest of the gear changes have been good. Downshifting 3rd to 2nd has always been tough at the track. I have Colin's shifter, and now the car just clicks into each gate.

Just goes to show that the clearances on these clutches must be pretty tight, but when they are set correctly, they work great.
If someone doesn't beat me to it, I'll try to post the WSM page that has the adjustment procedure/specs, I don't have them on my laptop. Basically it was setting the three adjusters on the intermediate plate to the clearance spec in the WSM, and welding them in place so that they don't move. Install per WSM instructions, and you're good to go.

atb

BC, I guess I should clarify, I had the I/P out of the car at the time.
Ken cut up a feeler gauge blade that was the correct tolerance into six pieces, and inserted the pieces on to either side of the "H" adjusters, so they couldn't rotate on their mounting pins. He then went around and tacked them in place, and removed the feeler gauge material with needle nose pliers.

Dave928S

You can also drill out the rivets (which get loose and allow it to move out of adjustment) and replace them with bolts, nuts and lock washers, to allow you to adjust and then lock in that position.
Someone in Europe did that (nice neat job) and a year or more later it was working like a charm ... might have been Errka? .... I'll search for that thread which I might have saved and post when I find it.

BC

Thanks. I think I may try and do this on a few cars I have here. Some IPs are newer, some older. Obviously this is not as god intended, but if it works....

God also did not intend for the the cost of a new IP to be the same as a good early S3 with bad paint. And the total cost of a new clutch job (just in parts) to be equal to an early S3 with GOOD paint.

BC

Right, thank you. So we know the drill - adjust, drive, adjust drive. The bad ones move immediately, the good ones move... later. So BEFORE it moves, and AFTER you have test driven, its taken out and welded?

I'm Sorry, I have SQL on my brain right now so I have some memory leaks at the moment.

GregBBRD

Obviously, Porsche could have done this, directly from the factory....but then what would happen when the clutch discs wore? (The "H" stop will no longer allow the intermediate plate to apply pressure to the disc against the flywheel, if it can't move.)

That's why they made them adjustable....

When the "H" pieces and rivets wear to the point where the "H" piece moves easily....replacing the intermediate plate will fix the problem.

brutus

More accurately stated they made them "self adjusting". If new intermediate plates only cost $200 there would be little discussion everyone would just replace them as this is how most dealer clutch replacements were done in the past. Since not many people recognize that the rivets and H pieces are wear items as the cars became worth less few people were replacing the intermediate plate since the friction ring surface might look pretty good and the part "costs too much".

Mrmerlin

[QUOTE=BC;9294126]Right, thank you. So we know the drill - adjust, drive, adjust drive. The bad ones move immediately, the good ones move... later. So BEFORE it moves, and AFTER you have test driven, its taken out and welded?

If your going to do this mod driving the car prior to tack,bolting, pinning the H plate
Is Not part of the process , though that will be your clue that you have a problem with a dragging clutch.


The freeplay is checked on the lift with the clutch IP installed,
and the feeler gauges positioned then the parts are tacked,
then the feeler gauges are removed.

It sounds like the OP followed a different setting procedure with the parts out of the car

NOTE if the H plates are loose and / or you have tried this adjustment and the clutch is again dragging then tacking the plate or bolting or pinning it will hold the H plate in place.

NOTE as Greg said the adjustment may have to be redone as the discs wear, using bolts sounds like the best idea