964 clutch options and "while in there" items

[RedCoupe]

If you look at page 30-8 of the shop manual above there is a picture of compressing the pressure plate with a press. The block of wood is on the contact surface of the pressure plate, so the fingers are being pushed against their spring force.

[RedCoupe]

Ari, I just compared the G50 Pressure Plate to a 915, and the G50 Pressure Plate is a "Pull" type while the 915 is the traditional push on the fingers and pivot to release type. So, your understanding of the release mechanism is correct. Sorry about that! (Sound of Dope Slap being self applied!)

[bazar01]

Originally Posted by iamtheari

Am I wrong? I can't figure out how the pivoting release fork works if the throw-out bearing should push the center of the pressure plate toward the flywheel to release the clutch.

You are correct.
The 964 release bearing is the pull type unlike the traditional push type.

Since you have the LWF, you needed a longer release bearing to compensate for the thinner LWF compared to the DMF. If you use the shorter, it looks like the pressure plate will be pre-loaded thus causing the slippage.

[johnsjmc]

It IS a pull type clutch. I doubt you could have reassembled it with the too short( DMF)bearing ,but was unaware of the different spacer count for a turbo.
If the spacer was different it might explain a slight drag ,but can,t see how it would explain a slippage issue.

[iamtheari]

I have the right TOB. I think assembly would have been much harder if not and I ordered the exact part number that comes with the Pelican LWFW kit.

The slippage is not a lot in relative terms. For example, the car does accelerate to catch up to the engine fairly quickly. Maybe one second lag for a 1,000 rpm increase at low speeds. So it's not quite like putting your foot on the clutch pedal where I would expect to have continued slippage. Then again, I have never in my life driven more than a car length with a clutch pedal partially depressed so this is a purely theoretical comparison.

The weather here stinks so I haven't driven the car again yet. I really should have bought all season or winter tires for the 16" rims, but I didn't want to be overly confident in my ability to put the car back together before "spring."

[iamtheari]

Finally got out for a 20-mile drive. It slips whenever I accelerate. And it hasn't improved. Because it is undrivable on the highway, I have concluded that I need to drop the engine again and see what I can see. I suppose I will start that in the morning. Not sure what to look for but I do think I will order a brand new pressure plate as this one is the only potentially mismatched part.

Any thoughts on what to look for once the car is on jack stands and before the engine comes out? Maybe have my wife push the clutch pedal and watch the inspection hole with a mirror, or try to wiggle the release fork through the hole and see if it has any slack? (I think it isn't supposed to have any slack with the slave cylinder in place, though.)

Maybe I shoukd have out cheaper oil in it given my 25-mile oil change interval.

[johnsjmc]

Not so fast .
When you start disassembly loosen the slave cyl a couple or 3 turns on the nuts. Test again. Is there a chance the pushrod is jammed in outside the socket where it belongs and is holding the clutch away from full /proper hookup.

[iamtheari]

By test again, do you mean to drive it with the slave cylinder nuts backed off?

It is unlikely but remotely possible that I did get the slave cylinder piston shaft misaligned when I installed it. It was not easy to put it in. But I do recall being vigilant about that issue to ensure it was in the cup on the release fork. And it seems like it should have worked in or out of the cup by now, either giving me normal operation or leaving me without the ability to disengage the clutch. That will have to be something I check with a mirror while someone else pushes the pedal.

[perelet]

Originally Posted by iamtheari

....

Maybe I shoukd have out cheaper oil in it given my 25-mile oil change interval.

that's rule #3, also keep old filter. Put good stuff in once everything works.

I think modern pressure plates are designed to wear off faster than clutch surface. This guarantees that it will start to slip before clutch wears to rivets and it explodes damaging more pieces . Used pressure plate is probably not way to go.

Also make sure you put retaining ring and it sits. Knees may work, but hydraulic press is fraction of the cost and you'll have much more use fot it.

PS. DWFW is not bad thing for general purpose car, and fact is - it is less $$$ overall. There's way too much hype about LWFW, i think installers are making much more profit on them. I'll post #numbers and detailed thoughts. That said I put LWFW

Oleg.

[johnsjmc]

Yes,
my thought would be test with slave loosened a few turns on both studs.
.That should let the pressure plate fully clamp and eliminate the hydraulics and linkage from the equation.
If it still slips then R&R further .
Could you have only caught one ear of the throwout brg ? I,ve seen that with it slipping off on mating the transaxle.

[iamtheari]

I don't think it slipped off the TOB at all. After I mated the engine and transmission and replaced the pivot shaft, I tested the movement of the fork by hand. It had just a small amount of free play and moved smoothly. That's why my line of attack is focused on the things that I am less confident I did correctly: pressure plate is culprit #1. I will give the slave cylinder a very careful look, the best I can given its bad location for viewing, because it is also a possible problem and even though I fear trying to work on it it is still easier than dropping the whole engine again.

Oleg: A new clutch disc for the DMF would have been a lot cheaper, that's for sure! I believe that the TOB not securely mounting to the pressure plate would prevent the clutch from disengaging with the pedal, so I feel that this isn't the problem. I pushed and pulled a lot to see if I could dislodge it before I put it on the car. Initially I did pull it free because I had not seated it completely due to not using enough weight to compress the spring washer. I'd like to have a hydraulic press, and many other tools, but then I would have no place to park my car.

[johnsjmc]

More I think about it You might have the starter ring gear backwards. Your LWF parts all look correct.

[iamtheari]

You've been brainstorming on my behalf a lot. I appreciate that. Any thoughts on testing the theory without dropping the engine? Shouldn't I have starter issues if I have the ring gear backwards?

I don't recall which way I put the ring gear on. I recall tapping it into place around the flywheel and measuring the gap between the reference sensor teeth and the ring gear teeth to compare with the original parts I had removed. If there is an interface between ring gear and pressure plate that depends on orientation, I did not check that.

[johnsjmc]

Originally Posted by iamtheari

You've been brainstorming on my behalf a lot. I appreciate that. Any thoughts on testing the theory without dropping the engine? Shouldn't I have starter issues if I have the ring gear backwards?

I don't recall which way I put the ring gear on. I recall tapping it into place around the flywheel and measuring the gap between the reference sensor teeth and the ring gear teeth to compare with the original parts I had removed. If there is an interface between ring gear and pressure plate that depends on orientation, I did not check that.

Did you take any pics during assembly you can review? The ring gear can be put on upside down. I recall thinking about orientation during my g50 clutch job but don,t recall for sure which way I ended. There is a raised lip on one side which might keep the PP away from full clamping on the disc.
I found a ref on rennlist about the ring gear being found backwards when it was suspected of being the upside down disc. Result was slippage .
I suppose you can see the ring gear after removal of the starter before digging much deeper.

[iamtheari]

Sadly, I did not take pictures during assembly. That's a lesson learned here and I'm glad I learned it on this project instead of an engine rebuild.

After sleeping on it, and googling to find I think the same thread on Rennlist that you did, I think you are probably right that my problem is there. I recall that the ring gear was flat on one side and had an inner lip on the other side. I believe that I put the lip toward the engine. Information I am seeing now shows the lip toward the pressure plate, which fits around the lip.

So rather than spending the next week trying to figure out where I put the handy inspection mirror that I recently bought, I think I'll just start dropping the engine.

[iamtheari]

Sadly, I did not take pictures during assembly. That's a lesson learned here and I'm glad I learned it on this project instead of an engine rebuild.

After sleeping on it, and googling to find I think the same thread on Rennlist that you did, I think you are probably right that my problem is there. I recall that the ring gear was flat on one side and had an inner lip on the other side. I believe that I put the lip toward the engine. Information I am seeing now shows the lip toward the pressure plate, which fits around the lip.

So rather than spending the next week trying to figure out where I put the handy inspection mirror that I recently bought, I think I'll just start dropping the engine. I think that's actually going to be easier than removing the starter and looking at the ring gear with the engine in the car. Since the engine and transmission are freshly joined this time, they should be easy to separate.

[iamtheari]

John: I will remember to bring a case of your favorite beer if I travel to Ontario. You hit the nail on the head. The ring gear was installed backwards. I used my intuition and thought its tight fit around the flywheel was correct. My intuition was evidently wrong. Facing the cut-away side of the ring gear away from the engine, the pressure plate sits inside the cut away.

Point of reference: It took 4 hours to remove the engine the second time, compared with 8-1/2 hours the first time. I won't try to put it back in tonight, though. That's just tempting fate.

[bazar01]

Originally Posted by iamtheari

John: I will remember to bring a case of your favorite beer if I travel to Ontario. You hit the nail on the head. The ring gear was installed backwards. I used my intuition and thought its tight fit around the flywheel was correct. My intuition was evidently wrong. Facing the cut-away side of the ring gear away from the engine, the pressure plate sits inside the cut away.

Point of reference: It took 4 hours to remove the engine the second time, compared with 8-1/2 hours the first time. I won't try to put it back in tonight, though. That's just tempting fate.

Glad you found the culprit. 4 hours to drop the second time is impressive.

Some people even forget to remove this ring gear from the old DMF and reinstall to the new LWF.

[wesleyc]

Impressive indeed ! I dropped mine a second time in 7 hours and thought I was speedy

[iamtheari]

I got a brand new ring gear. My entire DMF setup is on a shelf and everything between the engine and transmission is a new part. So I didn't even look at how the other one was installed other than spacing between starter gear teeth and flywheel gear teeth.

I didn't count draining oil and draining the gas tank in that 4 hours. My siphon pump has a really small ID hose so it drained about 3 gallons per hour and I had a full tank. But I was definitely proud of myself and pleased with my results. I started actually removing things after I put the fuel level sending unit back at 1:00 p.m., thinking that I would probably get fluid and electrical lines disconnected but no mechanical connections undone before quitting for the night. I took notes from the first engine drop and created a checklist for removing and a separate checklist for installing the engine. By organizing the steps and having sandwich bags with note cards ready ahead of time, I could crawl under the car and remove fasteners according to which bag I picked up off the top of the pile and keep going until I ran out of bags. If I had made "catch escaping oil" bold I probably would have saved another 5 minutes of scrambling to wipe oil off myself and the floor. Oops.

Installing it again will probably take more time. But less than the first time, I hope. There were a few things I learned along the way. One is to keep the right front wheel on the car. Remove the left one so you can use the wheel lugs to brace it against rotating forward, then roll the right wheel backwards with your foot to rotate the central drive shaft and line up the bolts on the clamping sleeve. Getting out from under the car to rotate the wheel hub a few degrees at a time was a good work-out but a waste of time.

I'll try to post my checklists in a new thread when I am done and verify they both work. I still have some items to shuffle around and I have tried to add fastener sizes and torques to each step to avoid going back to the toolbox more often than necessary.