Toasted Clutch?

[Zed Head]

Thanks for the reply. Maybe they stopped putting the collar in because of all of the returns for "wrong part."

Edit - I wrote a bunch but most of it is covered in Dizeazd's link...

One last thought, your throwout bearing and collar looks very gummed up. It has to slide back on the transmission main shaft front cover cylindrical portion to release the pressure on the clutch. I wonder if yours was jamming on the cover. Make sure the collar slides freely back and forth.

I am interested because I don't want to get stuck in this situation! Still looking for the definitive measurements to ensure everything will work together.

Last, last edit - Removing comments. I'm just adding to the confusion...

Edited February 14, 2011 by Zed Head

[hogie]

I also double checked the heighth of the fingers on the pressure plate. It was close to 1 3/4", not the 2" required for the 240 collar. Argh.

[Zed Head]

The pictures that Carl posted in the link that Dizeazd gave are very useful in showing that there are at least four collars out there. But there are no measurements associated.

Here are some measurements from parts that I know, for reference (I still have these parts for some reason) -

The dimensions for my 1976 4 speed 2 seater (225 mm clutch aka 8 inch) is 1 13/16 inches from the bearing surface (where the clutch fingers touch) to the tops of the ears (where the fork rides). This collar was used with a pressure plate that measured 2" from mounting surface to the tops of the fingers. I drove this around for quite a while before I replaced the clutch when I replaced the transmission with the 5 speed.

I have the collar and pressure plate from the 1978 280Z that apparently drove fine when it was parked. The transmission had all the signs of never having been removed. It too had a 1 13/16" collar, but the pressure plate measured 1 3/4".

The 4 speed 1976 transmission is the FS5W71A which has the identical bell housing to the 1978 5 speed FS5W71B.

So there is a 1 13/16" collar dimension used with both a 1 3/4" and 2" pressure plates heights, on an L28 with either and FS5W71A or ...B transmission.

I would guess that your new pressure plate is the latest 280Z style. If you have the later 5 speed, the 1 13/16" collar should work for sure, maybe with any transmission.

Thanks for giving me a reason to go dig through my old parts. I did not even realize that my pressure plates were of different height. I had just bought the clutch set for a 78 280Z when I did the trans swap, put it all in and apparently got lucky.

[grantf]

I bought the car undrivable, but got it moving this summer. All told I maybe put 300 - 400 miles on it between June and Oct. It started out slipping in 3rd and 4th, but it was only at full throttle. Eventually it started to do it in 2nd. It was weird having the engine rev up and then the car catch up to the proper speed. It wasnt a complete slip where only the engine revved and the car didn't move.

I wish I would've thought about looking into the clutch mechanism with a mirror before pulling it apart. Assuming my son cooperates I should be able to get a picture of the throw out bearing and collar posted tonight.

I also think the flywheel looks freshly resurfaced. The clutch only makes contact with that inner area so that would make sense to be cleaned up there. Though I would think that would be more complicated to machine.

I have 3 unknown quality transmissions so I was going to try those before pulling the transmission apart. Though it is not a bad idea to check the syncros.

Are all parts still out of the car? if so it is not a bad idea to have you're flywheel machined, they will pull the alignment pins out and the flywheel will be even across it's surface insuring the proper mounting distance for you're new clutch and pressure plate. this may not be the cause of you're slip-age but considering the time to pull all of these parts it would be good practice. I have a 5 speed that I just changed the clutch on, I was shure not to buy A 2X2 clutch kit, it came with the pressure plate, clutch, throwout bearing, and pilot bushing, works great. Not shure about you're callar as I did not take measurements of mine. hope I am not confusing the situation.

Edited February 15, 2011 by grantf

[Carl Beck]

I also double checked the heighth of the fingers on the pressure plate. It was close to 1 3/4", not the 2" required for the 240 collar. Argh.

From my notes:

For 1.75" high fingers - the throw-out bearing sleeve should be 28mm. The Part Number is 30501-1C104 (about $18.00 suggested retail from Nissan).

FWIW,

Carl B.

[Zed Head]

Is that the typical place to measure the sleeve/collar?

The 1 13/16" collars I mentioned, also measure out to 28mm (~ 1 1/8") using Carl's measurement points. One more data point.

It looks like hogie has all of the parts for a 280Z coupe clutch. What are the measurements on the original parts that didn't work?

[Carl Beck]

Here is an older diagram I was working on.. but wanted to verify the measurements before publishing...

The Throw-Out Bearings are about 19mm. So add 28mm+19mm and you get pretty close to 47mm or 1.85" or 1 13/16's inch.

FWIW,

Carl B.

[Zed Head]

Thanks for the information Carl. I wil be saving this thread for future reference. I wonder if hogie had a 240 mm (2+2) pressure plate with a 28 mm sleeve similar to ktm's situation in the other thread, but somehow the PO got it bolted together?

hogie, if you want to be sure that your slave cylinder is not bottomed out, holding some pressure on your pressure plate fingers, note that on my car, I can pull the slave cylinder rod back and remove it from its spot on the fork without unbolting anything. There is enough unused travel in the slave cylinder to do that. If your slave cylinder was bottomed mechanically, you won't be able to do that.

Edited February 15, 2011 by Zed Head

[hogie]

This thread sure has got a bunch of attention today. I have a MSA 21-2121 70-74 collar on the way as well as another clutch from them. Too bad I didn't see the post about using the longer collar for the Zoom pressure plate until after MSA shoved mine in the mail.

I know for sure that I was unable to move the slave rod away from the clutch fork by hand. I will check for play once I get everything in.

I also just got the flywheel back from a super nice old guy with a machine shop in his basement. I already like to spend time in the garage, I don't think my wife would ever see me if I had the same set-up.

Edited February 15, 2011 by hogie

[Carl Beck]

Hi Hogie:

Make sure you measure the height of the clutch pressure plate fingers and let us know what you received. Also check the actual length of the collar and compare them to the diagram I Posted..

Pictures of the ZOOM and MSA Pressure plates side by side would be GREAT...

thanks,

Carl B.

Edited February 15, 2011 by Carl Beck

[hogie]

Ok, MSA sent me the following part...however it looks nothing like any of the clutch collars I have seen. Does this look like the proper collar? Sorry for the fuzzy pics. I haven't seen any of these online with the blocky projections from the body.

Also, I swear if you google the part number it comes up as a 350z part. Unfortuneatly, I don't have the box in front of me. I just got a call back from them and they said this part superceded the old number and that it is used in a ton of vehicles.

Edited February 18, 2011 by hogie

[Zed Head]

Howdy hogie. It does look different than old factory stock but the necessary bearing surfaces are there. The tops of the ears and the bearing and the spring clip are the only contact points. If you look at Carl's pictures in Post#31, you can probably figure out where to measure from to see what you have. They sent you the collar/sleeve with no bearing, so you'll have to measure from the top of the ears to where the top of the bearing would be.

It does look like a short one though. Maybe a 240Z collar/sleeve. If so, it certainly won't jam your clutch partially open, but may not disengage it fully either. You might need an adjustable slave rod.

Edit - actually it looks like it might be designed to handle two different bearings. I would guess that your bearing will only press up onn the narrow section, so it is probably taller than it looks in use. If you have a bearing, you could guesstimate where it will end up once pressed on take a measurement there.

I looked back at your pictures but can't read the tape on your measurements. How does the new one measure out compared to the old one?

Edited February 18, 2011 by Zed Head