Charley B

The WSM tells me the clutch is automatically adjusted, but I think I could use just a smidge more pedal reach.

I don't have any creep when sitting still in gear, but the gears feel extremely notchy.

Would I get some relief by adusting the rod out a little? Or am I barking up a totally wrong tree here?

I'm heading for the track in the morning, and I'm a little nervous about heeling and toeing a car I'm unfamiliar with, and then adding reluctant shifts into the mix.

I have been known to ruin perfectly good clutches before. I need every edge I can get.

Dennis Wilson

Charley,

Have you checked the preload (under the dash) on the master cylinder since you changed things out? Too much clearance will affect the engagement.

Dennis

nosnow

There are a few things I noticed with on my 82:
- The type grease on the small shaft is very important as this is a sticking point, in winter on really cold days my clutch will occationally drag until the engine is hot.
- The "T" adjustsers on the intermediate plate can also become tired, if you adjust them to the max position and the release the clutch they are suppose to auto adjust
- I noticed new clutch disks took a good 1000 miles to break in.
- My tranny originally had Redline and I found when I switched to Mobile1 the shifting was better.

You want to becareful adjusting the clutch master to help with the release. There are specific measurements on where the rod is suppose to sit. If you change this you have the risk of screwing up the bleeding at a bad moment. If the master is adjusted too far new fluid isn't allowed in and enevitably there is a problem.

Hupp, explains the adjustment of the master here.
https://rennlist.com/forums/showthre...ter+adjustment

Mrmerlin

do you think you might have some air in the lines Chas?

Charley B

Maybe I shoud have mentioned, although I don't think it matters; the engine, clutch and tranny are from an '83 Euro.

Dennis - I haven't checked the preload by backing out and resetting it. There is no play, so the preload has been set. I gave the rod one more turn out just to see if there was a difference, and there was no improvement.

Paul - I haven't checked the T - adjusters, I thought that was all self adjusting once set. The clutch has 25K miles on it. I don't know what is in the tranny.

Stan - I'm not sure how to tell if this is caused by a little air in the system, other than to just bleed the system. I'm not even sure I have a clutch issue at all. It just seems that a tranny that was rebuilt 25K miles ago, with new synchros, should be a little easier to shift. I just started driving this car so I don't know if there has been a deterioration, or if it has always been this way. I also have never driven a pre '85 5 spd. My GTS is a little stiff going into 2nd when cold, but other than that it's like butter compared to this one.

Mrmerlin

does the car seem to want to roll when its in gear and stopped? How low does the pedal go before the clutch is disengaged. ? What kind of oil is in the trans?

nosnow

The best way to see if the clutch is dragging.... put the car in neutral and disingage the clutch. Engage the clutch try to put it in reverse (allow enough time for your trans to spin down). If there is a crunch your clutch is probaby dragging. Also check the ball cup on the release arm to see if it has started to disintegrate.

My tranny was rebuilt by Devek shortly before I bought the car. I changed the fluid when I got it and it was full of shavings. I was pretty ill. I replaced the fluid and the shifting improved a great deal. I changed the fluid again ~2K miles later and now when the trans is warm it shifts pretty nicely. Still a lot heavier than my subi.

mark kibort

after driving a bunch of different 928s, i can tell you that a fully functionng transmission 85 and later should be a dream to shift. it should seem as though the gear shifter is "sucked" into gear. there should never be any grinding or force needed to shift. If there is, the transmission is probably at fault.
Because of the earlier transmission design, they can be "notchy" in most all of the lower gears, with 1st and 2nd being the most sensitive.
one thing even the later 928s are sensitive to, is a non-fully depressed clutch pedal. this will create some shift issues.
I have never understood anything about the "adjustments" made to a clutch. Ive put in about 10 of them, did a conversion of the holbert car to the early clutch, and have never had an issue. Still, i wouldnt know how to do an adjustment if i had to do one. they all seem to work the same when they are installed.

mk

Mrmerlin

adjustment is covered in the WSM it is for adjusting the freeplay of the master cylinder and also the setting of the intermediate plate so it fully releases from both discs

Charley B

I'm not getting any creep or drag. However, last night I turned the rod one turn toward the clutch master and didn't notice a difference, but when I started the car at 6AM, with the idle at about 1050, it would not shift into reverse. Had to shut it off, put it in reverse and start it. I adusted it the other way two revolutions (toward the pedal) and it shifted better. I'm tempted to give it one more revolution, but I'm a little leary of causing the fluid displacement problem that Paul mentioned.

Stan, I believe it has Swepco 75-90 in it. The pedal seems to engage and disengage at about the right point.

The clutch is the double disc type.

Andre Hedrick

You up for doing adjustments on OB's ?

marton

Paul posted
Which small shaft are you talking about (slave cylinder?) & what type of grease did you find to be good?

Marton

Dennis Wilson

Charley,

The 91 revision to the WSM indicates the rod should be adjusted until it just meets the master cylinder, then lenghtened one revolution (360 degees) to preload the clutch. I'm not sure why this change was made but it stoped the notchiness on my 78. I wouldn't preload more than the one revolution.

Dennis

hupp

You had too much pre-load by adjusting the rod in more. The master piston had been effectively moved forward too far and was restricting the ports that allow the fluid to move freely.

The notchiness you describe sounds like it's "the nature of the beast". You can try different gear oils and may be this will improve things. As far as the release point, my clutch releases right off the floor as well -- I have read before that this is normal for the earlier double disc set-ups.

nosnow

The Central Clutch Shaft. It is the shaft that the clutch disks and intermediate plate are mounted on. If the lube is too thick the disks and intermediate plate can stick. The other issue is that the splines on this shaft might also have a wear point which causes sticking. Sorry for my earlier "small shaft" technical term.