Another clutch issue thread

Jeff NJ · 08-19-2014, 07:50 PM

I have an 88 930 and over the past couple weeks, it has been harder and harder to get the car into reverse. I am at the point where I turn off the car, put it in reverse and then turn it back on. Really bad grinding otherwise. I adjusted the cable to spec for the 1.2mm gap from the short clutch arm to the adjuster bolt with the cable off and then 1mm with the cable on and tightened, but I cant get the 25mm cable throw that is spec. I get like 22mm. It seems the clutch is not completely releasing and so the gears are spinning and not stopping. The book says to adjust the clutch pedal travel at the floorboard to get the proper travel, but it is hitting the floorboard and wont go any further. I removed the floorboard and when I have it running and push the pedal past where the floorboard would stop it, I am able to get it into reverse with a very minimum of grinding. You can hear the gears hitting lightly, stopping the gear and then it slips right in. If I pull it out of reverse (but don't bring the lever to the right and keep the clutch pedal all the way depressed) and then put it right back in, it grinds again a little. This tells me that the clutch STILL isn't releasing all the way and the gears start spinning due to clutch friction even though my clutch pedal is way past where the floorboard would stop it.

The cable, the omega spring, the clevis and clevis bushing were all replaced few months ago and it worked fine for 1200 miles. The bushings in the pedal cluster look original (plastic), but I cannot see any slop in there when depressing the pedal. No rust either. Car has 59k miles and the clutch was replaced by the PO about 11k miles ago in 2003. The receipt doesn't specify the clutch type or manufacturer and only shows that the clutch was replaced (no other parts listed).

So, two questions:
Without notching the wood floorboard, how do you get more travel in the clutch? Are there any adjustments up by the pedal to give it more throw? What causes it to not travel as far as it used to?

What would cause it to take a longer than 25mm throw to release enough to get it into reverse while seemingly never really completely releasing? Could it be the fork inside the clutch failing? What else would wear to cause the decrease in travel?

OK, that's five questions...

Any ideas from the braintrust here? I am at a loss.

I read every thread I could find (and there are lots of them!), but haven't gleaned the info I need.
I posted this question in the 930 section yesterday, but it doesn't get nearly as much traffic over there and no responses yet and the 915 clutch is very similar mechanically so I'm hoping help arrives!

DRACO A5OG · DRACO A5OG's Garage

Yes, at the clevis (ball cap) it can be dialed out to make up the 3+ MM need for your pedal throw specs.

Just take care not to take it out too much as not to properly thread it adequately, there is a jam nut just make sure it is secure.

Yes, it could be the fork, if after this final adjustment, you still have grinding then it may be the fork. So POS receipt did not show if the fork was replaced, right? Damn, freakin wrench going cheap but I bet he charged for a complete clutch job???

In anycase, try the final adjustment and keep an eye on it. To save your gears, stop the gears by touching second before going into reverse until you solve this issue. I would also change the gear lube to see if you got bit and pieces in there.

I hope POS changed the pressure plate too and not just the friction ( clutch ) plate.

Jim

T77911S · 03:02 AM

does it grind going into 1st or second before going into reverse? if it goes into these 2 gears OK i would think it is in the tranny, no?

it uses the fire wall as the "holder" or stop for the clutch cable going to the pedal cluster right? check that to see if it is bent or rusted and flexing

every once in a while mine will not go into reverse. i have to let the clutch out just a tad to turn the gears so somehting lines up then it slips in, no grinding though.

zelrik911 · zelrik911's Garage

Sounds like the Fork may be bending, if it wasnt replaced?

In my car I suspect that the splines in this short arm & the tower shaft splines are wearing thin and there is too much free movement between them to make a good 1.2mm & 1mm adjustment.

CCM911 · 08-20-2014, 05:57 AM

When I replaced my clutch cable, I did the same thing that DRACO is describing below. You need to take up as much slack as possible up front(on the clevis) in order to be able to make precise adjustments at the clutch arm.

Quote:

Originally Posted by DRACO A5OG

Yes, at the clevis (ball cap) it can be dialed out to make up the 3+ MM need for your pedal throw specs.

Just take care not to take it out too much as not to properly thread it adequately, there is a jam nut just make sure it is secure.

Yes, it could be the fork, if after this final adjustment, you still have grinding then it may be the fork. So POS receipt did not show if the fork was replaced, right? Damn, freakin wrench going cheap but I bet he charged for a complete clutch job???

In anycase, try the final adjustment and keep an eye on it. To save your gears, stop the gears by touching second before going into reverse until you solve this issue. I would also change the gear lube to see if you got bit and pieces in there.

I hope POS changed the pressure plate too and not just the friction ( clutch ) plate.

Jim

Jeff NJ · 08-20-2014, 12:08 PM

Thanks for the responses. Here are some answers to the questions/observations posted.

Quote:

Originally Posted by DRACO A5OG

Yes, at the clevis (ball cap) it can be dialed out to make up the 3+ MM need for your pedal throw specs.

Just take care not to take it out too much as not to properly thread it adequately, there is a jam nut just make sure it is secure.

Just to be clear, are you talking about the clevis pin on the end of the clutch cable or the threaded adjuster on the spring that is attached to the pedal? The pedal comes to rest on the forward stop when I release the clutch and hits the wood when I push it in, so I am not sure how to get a longer throw since both ends of the pedal travel come up against hard stops.

Quote:

Originally Posted by DRACO A5OG

Yes, it could be the fork, if after this final adjustment, you still have grinding then it may be the fork. So POS receipt did not show if the fork was replaced, right? Damn, freakin wrench going cheap but I bet he charged for a complete clutch job???

In anycase, try the final adjustment and keep an eye on it. To save your gears, stop the gears by touching second before going into reverse until you solve this issue. I would also change the gear lube to see if you got bit and pieces in there.

I hope POS changed the pressure plate too and not just the friction ( clutch ) plate.

Jim

Going into 2nd doesnt help me. The clutch friction seems to cause the reverse gears to spin up real fast. I just turn off the car to get it in reverse. I actually did buy some Swepco and was planning on changing the trans oil. Hopefully it is not full of bits and pieces...

Quote:

Originally Posted by T77911S

does it grind going into 1st or second before going into reverse? if it goes into these 2 gears OK i would think it is in the tranny, no?

it uses the fire wall as the "holder" or stop for the clutch cable going to the pedal cluster right? check that to see if it is bent or rusted and flexing

It does not grind in any other gears. It just seems as though the clutch is not releasing enough. Forward gears don't need the clutch 100% released since they have synchros.

I did triple check to make sure the cable end into the firewall is correctly inserted when I adjusted the cable again the other day.

Quote:

Originally Posted by zelrik911

In my car I suspect that the splines in this short arm & the tower shaft splines are wearing thin and there is too much free movement between them to make a good 1.2mm & 1mm adjustment.

Quote:

Originally Posted by CCM911

When I replaced my clutch cable, I did the same thing that DRACO is describing below. You need to take up as much slack as possible up front(on the clevis) in order to be able to make precise adjustments at the clutch arm.

I believe I am good in this respect. I am able to get a good, precise adjustment for the 1.2 and 1.0mm gaps that do not change with use.

will hung · 08-20-2014, 12:20 PM

Quote:

Originally Posted by CCM911

When I replaced my clutch cable, I did the same thing that DRACO is describing below. You need to take up as much slack as possible up front(on the clevis) in order to be able to make precise adjustments at the clutch arm.

I can second this. I read somewhere here that the new clutch cables are slightly different in length than they used to be. So you have to adjust them more at the clevis pin. Makes adjustment a pain since you have to reach your fingers into such a tight spot to remove the clevis pin and adjust the length.

Also take a close look where the clevis pin is inserted in your pedal box. Over time, they wear the hole from a perfect circle into an oval and create play.

DRACO A5OG · DRACO A5OG's Garage

Sorry, I mean dial in, take up the slack at the clevis which at the pedal cluster. But before that try to take pic of the bowden metal bend to insure it is in the correct place.