Clutch Starting to Slip...?

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GasDaddy140
Posts: 327
Joined: Tue Aug 19, 2014 1:57 pm

Clutch Starting to Slip...?

Post by GasDaddy140 »

Hi!
I have noticed my clutch starting to slip under acceleration, it has only been in the car about 10,000 miles. I always thought that it may be adjusted too loose, a lot of pedal, but wasn't sure. Any thoughts on adjustments helping out this situation? It's a 1965 Corsa 140.
Thank You!
Alan
Alan Duquette
Rohnert Park, CA
"When in doubt...Hit the gas!" A.J. Foyt.

1965 Corvair Corsa (field find) Project
1971 Dodge Sportsman "shorty" 318 van
2015 Nissan Juke S
erco
Posts: 1489
Joined: Wed Apr 29, 2020 8:45 pm

Re: Clutch Starting to Slip...?

Post by erco »

Any oil leaking on the clutch/PP? Could be engine or tranny oil.

As long as your clutch is adjusted properly (cable not too short/some slack when released) then it's all up to your pressure plate springs and clutch material to grab sufficiently. Was the PP replaced along with the disk 10K miles ago?
66vairguy
Posts: 4531
Joined: Tue Dec 21, 2010 3:44 pm

Re: Clutch Starting to Slip...?

Post by 66vairguy »

There is a spring on the clutch cable in back so the clutch pedal should move about 3/4" with light pressure until the lever pushes the throwout bearing against the clutch spring diaphragm and then the pedal will take considerable more pressure to move. No play and the pressure plate can't put full force on clutch disc. If that is O.K. then either the pressure plate is bad or the clutch is soaked in oil from a leaking seal on the main shaft.

Did you put sealer on the flywheel bolts if you had those out? No sealer and they will weep engine oil onto the flywheel and clutch.

BTW Erco THERE ARE NO NEW PRESSURE PLATES for the Corvair!! Only rebuilt and NONE of the rebuilders can get a new spring diaphragms so they just "test" the old diaphragm. If the diaphragm is bad then ONLY Clark's has new ones. Clark's stopped selling diaphragms separately years ago and if/when they run out who knows when they will be available. ONLY Clark's has new diaphragm springs (last time I checked) and for obvious reasons they use them only for THEIR rebuilt pressure plates.

A few years back a number of folks insisted their rebuilders installed new diaphragms. I said "Call them and confirm they are using NEW and not just tested diaphragms. After a few weeks NOBODY was able to find rebuilt pressure plates with new diaphragm springs, except at Clark's.

So feel free to call around, but every time I got a lead and talked with the shop manager I was told "No we don't install new diaphragms because they are NOT available, but we do test them". As I've learned "REBUILT" is a nebulous term.
erco
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Joined: Wed Apr 29, 2020 8:45 pm

Re: Clutch Starting to Slip...?

Post by erco »

That's sad & scary. Think I've only ever used rebuilt PPs, but that was 25 years ago last I was driving this car, when I recall reasonable parts prices & availability from my LAPS. Now I see fantastic prices ($200-250 after core swap) for "rebuilt" PPs, which is simply ridiculous if the diaphragms are used.

I better savor every shift whenever I get my heap rolling.
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GasDaddy140
Posts: 327
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Re: Clutch Starting to Slip...?

Post by GasDaddy140 »

Thanks to Everyone replying -

No oil leaks observed, did not change PP, did seal bolts. I took my Corsa for a drive last night and estimate I have a couple inches of clutch peddle free play before engagement. It's been like that. I suspect that I need to correct this first. Is there an adjustment or just the spring? I'm not even sure that I have the correct spring! But, maybe. Hope to get it jacked up for a look soon.

Alan
Alan Duquette
Rohnert Park, CA
"When in doubt...Hit the gas!" A.J. Foyt.

1965 Corvair Corsa (field find) Project
1971 Dodge Sportsman "shorty" 318 van
2015 Nissan Juke S
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GasDaddy140
Posts: 327
Joined: Tue Aug 19, 2014 1:57 pm

Re: Clutch Starting to Slip...?

Post by GasDaddy140 »

Just saw a great, as usual, post by Brad Bodie regarding adjusting the clutch cable. I'll start there because it feels wrong.
Alan Duquette
Rohnert Park, CA
"When in doubt...Hit the gas!" A.J. Foyt.

1965 Corvair Corsa (field find) Project
1971 Dodge Sportsman "shorty" 318 van
2015 Nissan Juke S
joelsplace
Posts: 1950
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: Clutch Starting to Slip...?

Post by joelsplace »

Free play won't make the clutch slip. No free play will make it slip.
157 Corvairs, 5 Ultravans and counting
Northlake, TX
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GasDaddy140
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Re: Clutch Starting to Slip...?

Post by GasDaddy140 »

What I'm trying to say is, that when my clutch peddle is depressed to the floorboards, and then I start releasing it to engage the clutch, I have well more than 3/4" before engagement. My clutch peddle comes up pretty far with nothing happening :) It's been like that since I got it running.
Alan Duquette
Rohnert Park, CA
"When in doubt...Hit the gas!" A.J. Foyt.

1965 Corvair Corsa (field find) Project
1971 Dodge Sportsman "shorty" 318 van
2015 Nissan Juke S
joelsplace
Posts: 1950
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: Clutch Starting to Slip...?

Post by joelsplace »

That seems ok to me. If it starts engaging as soon as it starts coming off the floor you will probably have problems with it completely disengaging.
Free play is at the other end of the travel between fully off the pedal and where the pedal takes up the slack in the linkage.
157 Corvairs, 5 Ultravans and counting
Northlake, TX
erco
Posts: 1489
Joined: Wed Apr 29, 2020 8:45 pm

Re: Clutch Starting to Slip...?

Post by erco »

Clear as the water in Boston harbor. Do you mean 3/4 inch or 3/4 travel? Big difference.

If you meant 3/4 travel before engagement, you need to take out the slack. You have no free play. Bad for the clutch disk, pressure plate, and especially your throwout bearing, which is constantly spinning.
joelsplace
Posts: 1950
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: Clutch Starting to Slip...?

Post by joelsplace »

He said 3/4 inch. If that isn't what he meant then he has a problem.
157 Corvairs, 5 Ultravans and counting
Northlake, TX
erco
Posts: 1489
Joined: Wed Apr 29, 2020 8:45 pm

Re: Clutch Starting to Slip...?

Post by erco »

He said both 3/4" and "my clutch peddle (sic) comes up pretty far with nothing happening", which are not consistent.
joelsplace
Posts: 1950
Joined: Wed Oct 13, 2010 12:51 pm
Location: Northlake, TX

Re: Clutch Starting to Slip...?

Post by joelsplace »

True. That doesn't make sense.
157 Corvairs, 5 Ultravans and counting
Northlake, TX
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GasDaddy140
Posts: 327
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Re: Clutch Starting to Slip...?

Post by GasDaddy140 »

OK guys, I'm not trying to "peddle" anything :)
I thought the clutch should start engaging after about 3/4" or so with release of the clutch pedal off the floor board.
So, after work today, I disconnected the rod that moves the clutch lever. I shortened up the length by about 3 turns of the fine threaded rod, and reinstalled. It definitely tightened up the rod a bit. I then went for a short drive. Down shifted good and decelerated. Hit the gas and it went OK, but hard to tell. Short drive and all.
My son and I, especially my son ( As he learned how to drive a car in this heap and slide its ass-end out and stuff) do stand guilty of abusing the clutch at times.
I really appreciate all of your inputs! :tu: That's why I ask.
I've got to monitor this now and will report back.
Alan Duquette
Rohnert Park, CA
"When in doubt...Hit the gas!" A.J. Foyt.

1965 Corvair Corsa (field find) Project
1971 Dodge Sportsman "shorty" 318 van
2015 Nissan Juke S
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