Little bit of a frustration this weekend. Assumed the clutch was siezed, so we pulled the Trans to replace it (already replaced clutch master/slave cylinders, bled the system, ensured slave is engaging the fork sufficiently). New clutch didn't solve the issue; still isn't engaging. It has been suggested that I have the wrong size slave, or that the clutch fork isn't pivoting properly. I'm not sure. Owe a big debt of thanks to Fred B. for helping me pull the trans. He's a very patient man...

Anyway, while the transmission was out, I took some photos. It's a three-piece trans, but that's about all I can figure out. Based on the information here (http://www.zcarz.us/TechnicalInformationPageTransmission.htm), it doesn't appear to be a TypeA or TypeB. Looking elsewhere lest it's a roadster trans (http://www.311s.org/phpBB3/viewtopic.php?f=6&t=17016&sid=c1b52a373aa0e3c26f30678f68ed72c7, other CL ads), it doesn't appear to be one of those either.

I'm flummoxed! Anyone recognized this 5-Speed?

Edited August 13, 201212 yr by ksbeta

Relevant: This looks similar: http://www.zcar.com/for_sale_parts_accessories/rare_240z_5-speed_manual_transmission_fs5c71a_903615.0.html

Yep, that is the FS5C71A 5-speed that was available from the factory in other markets, but not in North America, unless you bought one through Datsun Comp, or modified a roadster transmission (which is why some people refer to it as a roadster transmission). It is the only 5-speed that is a direct fit for the early cars (70 & 71) that doesn't require modifications to the transmission tunnel/shifter/console.

-Mike

Thanks Mike, I suppose that's good news.

So, I'd need a stock 240z Slave Cylinder, and I'd be using a 240z throw-out bearing/ collar? Still trying to diagnose why my clutch won't engage.

It's the distance of the spring surface of the pressure plate from the back of the engine (its height) that matters, where the throwout bearing rides. If you're using a 280Z pressure plate, you would probably want a 280Z throwout collar. This is true for the later transmissions, but the early one that you have might have a different mounting spot for the slave. It might also use a different slave cylinder.

I don't know all of the details of your engine and transmission, but if it worked before and you have the old parts, you might look at the distances and relationships of the pressure plate spring surface, slave cylinder and slave mounting point. I have the critical distance for a 280Z but it might be different for what you're using.

By the way, if the clutch is seized and won't release the engine from the gearbox, then it is not "engaging". That's what it does - engage the engine and the gearbox. It's already engaged, the slave cylinder disengages it.

One more thing - new slave cylinders have been known to be bad from the stores. You have to measure travel to know if they're getting full movement. I had one that moved about half of its travel, it looked like it was working, by eyeball, but it wasn't

Zed - Thanks! The clutch definitely isn't siezed, I saw to that when I replaced it on Sat. I'll try using the old slave cylinder to see if that makes a difference (how easy of a fix would that be...) and if it does. I am using the new slave cylinder with the old slave clyinder rod... perhaps that combination was bad.

Forgive my lazy reference: You're correct, I can't get the clutch to disengage. Certainly helps to use the right terms.

I had pressure in the clutch line prior to removing the trans on Sat. After replacing it, that pressure was gone. Can't understand that one.

Thanks Mike, I suppose that's good news.

So, I'd need a stock 240z Slave Cylinder,

Yes

and I'd be using a 240z throw-out bearing

Yes they are all the same

collar?

NO - not if you changed the clutch Pressure Plate. The collar has to match the pressure plate. Almost all the replacement Pressure Plates are now the size/height of the 280Z and/or 280ZX pressure plates. So as mentioned already - you will most likely have to get the collar for a 280Z/280ZX.

Lay your NEW and OLD Pressure Plate flat on the floor. Measure from the floor to the top of the pressure plate fingers. The original 240Z Pressure Plates were thicker so the collars were shorter. The New Replacement Parts are thinner so the collars are longer. If you measure your older and newer Pressure Plates and they are the same height/thickness - only then would you use the same collar. {you never know what some previous owner put in there - so you can't assume its the original Pressure Plate}.

FWIW,

Carl B.

I had pressure in the clutch line prior to removing the trans on Sat. After replacing it, that pressure was gone.

"it" what is it? Did you mean to say that after you "reinstalled" the same transmission, the pressure was gone? Or are you saying that you replaced the clutch line? Big difference between reinstalling and replacing.. Did you do anything else when the trans was out?

BTW - DID you know that was a 5spd? Or is it a 5spd. You didn't say to begin with..

Carl B.

Edited August 13, 201212 yr by Carl Beck

Well, I see two problems emerging:

1) I don't know all the right parts still

I've poured over "How a clutch works" pictures today, and can't find the collar. Is the clutch collar at the end of the fork, and what physically touches the throw-out bearing?

2) I may have over estimated parts interchangability

I changed nothing with regards to the transmission. It definitely is a 5-Speed. I knew this going into the job. So whatever throwout bearing what in there before, is still in there now. I had purchased a bearing for a '69 Datsun 2000 5-Speed (having understood it was a Roadster trans), but it didn't match the part that was installed so I didn't change it out.

My pressure plate (& cover) are from a '77 280z. The clutch disc is the 240z disc that was installed (the replacement I ordered was the wrong size).

The motor is an L24, albiet not the original to the car. The stamp on the block is numbered somewhere in the 3,000's.

Slave cylinder is a Beck Arnley, P/n: 10769393

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Carl, I apologize for the poorly written statement, but you're correct: After reinstalling the same transmission, the pressure was gone. The only part that had been replaced then was the pressure plate & cover. Hadn't ever interrupted the hydrualics.

I did manage to get the two cars next to each other for the first time on Sat. though.