Transmission Grinding

[ksbeta]

Following up on two threads from the past few months:

http://www.classiczcars.com/forums/thread46932.html

http://www.classiczcars.com/forums/thread46662.html

Quick Recap: Transmission grinds when I start to put it in gear. I've replaced:

- Replaced Clutch Master Cylinder

- Replaced Clutch Slave Cylinder

- Replaced Entire Clutch Kit

- Bled System

Ensured proper travel at the Slave Cylinder. Ensured the Master Clinder is fully extended. If I put it in gear and start it (with a push) I can go around the block in gear, just can't shift (obviously).

So I'm totally out of ideas. I can't imagine why else the clutch wouldn't engage. The only saving grace is that I'm swapping the motor / transmission in the next month or two, it's just frustrating to not have gotten this thing moving after so long. Rebuilt those #%*& DGV carbs for no reason...

[cbuczesk]

My guess is that you have the wrong length collar. I can't think of anything else that it could be.

Chuck

[ksbeta]

Could be, Chuck. It's an L24 block, a 240z bell housing, and complete 240z clutch kit, so I'd hope it's all "correct" but clearly something isn't.

[cbuczesk]

I have a bunch of spare collars of different lengths if you want to try one.

Chuck

[Carl Beck]

Could be, Chuck. It's an L24 block, a 240z bell housing, and complete 240z clutch kit, so I'd hope it's all "correct" but clearly something isn't.

In my limited experience - there is no such thing as a "240Z clutch kit". The original Pressure Plates that came in the 70/73 240Z's from the Factory were thicker than the later 280Z Pressure Plates. In the past 10 years, I've never received a new Pressure Plate that was the same thickness as the original factory Pressure Plates that came in the 240Z's when they were produced.

No matter if you "order" a 240Z Pressure Plate or not - you most likely won't get one. What you will get is the newer replacement parts - which are in fact the thinner 280Z pressure plates.

In that case - you have to get a 280Z or 280ZX Throwout Bearing Collar.

The problem you describe sounds like you put the old 240Z Throwout Bearing Collar - in with a newer style -ie thinner - Pressure Plate.

Question: Did You Keep The Old Pressure Plate Handy? If so - set it side by side on a flat surface and see if it is the same height as the new one - when you pull the new one out. Measure the distance between the flat surface and the top of the pressure plate "fingers".

Of course - another cause for the problem you describe -is that the Clutch Disk can bond itself to the flywheel with Rust - if that car has been sitting without being driven for months and months.

FWIW,

Carl B.

Edited October 2, 2012 by Carl Beck

[MotoManMike]

Just curious how high does your engine idle?

[ksbeta]

Carl, Chuck, Thanks for the replies.

Question: Did You Keep The Old Pressure Plate Handy?

Yes, I certainly did. I'll compare them the next (third... [groan]) time I remove the transmission. Frustrating to think I bought a kit and it wouldn't work, but I suppose when it's not from Nissan, it wouldn't be guaranteed anyway.

Of course - another cause for the problem you describe -is that the Clutch Disk can bond itself to the flywheel with Rust...

This was my first thought; one of the above referenced threads documents my attempt to free that. The first time I dropped the transmission, I was looking for this rust but it wasn't there. The new parts have only been in for about 3-4 weeks.

Chuck - I may need to take you up on this; but first I need to see if the new transmission has all the parts. I appreciate the offer and will keep it in mind going forward.

Engine idles around 1k; I still need to fine-tune the carbs idle. Was interested in getting it moving first. If anyone wants some DGVs let me know. They'll be obsolete sometime this winter. This has been a giant lesson in humility, that's for sure.