Help identifying clutch system (1 Viewer)

[avicenna110]

I have a 65 FJ45 with a Chevy 350 engine (from a 73 corvette). It has the stock 3spd transmission. The bellhousing is the original GM and there is a 1” adapter between the transmission and the bellhousing. I’m rebuilding the transfer case and have removed the transmission so wanted to address the rear main seal leak and update the clutch components. I’d seen a lot of useful threads about Chevy+Toyota clutch system, and have some idea of what parts to get, but would like to know what I have first and go from there.

- The master/slave cylinders shown below seem both Toyota, but I’m not 100%. The push rod is modified

- the fork and release bearing seem to be GM

- would like to know if the clutch pressure plate and clutch I have is the low profile or the normal style

- since this is my first clutch replacement I don’t know if my clutch is worn or not by the looks of it

I’m replacing the clutch either way, was just curious. I’d like to resurface the flywheel as well but if it’s not that expensive I rather replace it vs finding a machine shop around here that would over charge me

Thanks

Some pics of my setup:

 

[avicenna110]

Some more

 

[whitey45]

All chevy clutch components, all toyota hydraulic. Everything looks low mileage and good to run? You can still see the machine marks on the flywheel. If it all worked fine, I would run it. You will open up a can of worms if you start to mix and match parts.

 

[pb4ugo]

I agree, I'd get a new throw out bearing and put it back together. I think the master is a earlier style. Are you having problems with the clutch?

 

[avicenna110]

Thanks guys. Yeah it ran fine, the clutch releases a bit higher than I’m used to with other cars so I wasn’t sure if it’s how FJ40s are, or whether the clutch disc was worn. I didn’t mess with the pedal adjustment yet so there might be room to lower it. I had to remove everything to get to the rear main seal anyways so I thought might as well update it if I need to. But it’s nice to hear everything looks good.

 

[pb4ugo]

If that's a 1st gen sbc you don't have to remove the tranny or flywheel to replace the rear main seal. The pan should just drop down. The seal should be a 2 piece seal. If you can you see the seal from the back of the engine its a later 1 piece seal.

Here's info on clutch adjustment.

 

[avicenna110]

If that's a 1st gen sbc you don't have to remove the tranny or flywheel to replace the rear main seal. The pan should just drop down. The seal should be a 2 piece seal. If you can you see the seal from the back of the engine its a later 1 piece seal.

Here's info on clutch adjustment.
View attachment 3113522

Thanks, that’s cool that you can change it without dropping the transmission. I don’t see if from the back so I’m fairly certain it’s the 2 piece kind.

I am rebuilding the transfer case and the rest of is what I thought would be good to do, although it has now grown to a large list of things to do. The transfer case was leaking and making a loud whinny noise, the culprit was the idle shaft, and the seal around it.

 

[B y r o n]

Here are some things I noticed in this photo:

The mounting plate for the slave cylinder is a block that spaces it out, probably to keep the rod straighter into the outside pivot spot. That throw out bearing arm actually has a second pivot point as shown in the red circle. Take a look at this adapter as it will allow you to use the inner pivot location which will translate to more throw. Download the documentation for it and it will have pictures of what I'm talking about.

 

[avicenna110]

Here are some things I noticed in this photo:

View attachment 3114653

The mounting plate for the slave cylinder is a block that spaces it out, probably to keep the rod straighter into the outside pivot spot. That throw out bearing arm actually has a second pivot point as shown in the red circle. Take a look at this adapter as it will allow you to use the inner pivot location which will translate to more throw. Download the documentation for it and it will have pictures of what I'm talking about.

Very nice, thank you!

 

[whitey45]

More throw, but less leverage and a harder clutch pedal

 

[B y r o n]

More throw, but less leverage and a harder clutch pedal

With a diaphragm clutch no big deal. Three finger clutch more effort is noticed but not necessarily negative.

 

[avicenna110]

Thanks guys for the insight. I think the bracket is cheap enough, and also the mod easy enough to try both variations and see which one is better suited for me.

The info here has been very helpful. Thank you.

 

[pbgbottle]

That pressure plate is not the low profile one either. Did your clutch slip or did it work fine.

 

[avicenna110]

That pressure plate is not the low profile one either. Did your clutch slip or did it work fine.

Thanks was wondering about that. The clutch worked fine. Based on what others said I’ll keep it the way it is. I just bought the release bearing so I’ll put that on.

 

[avicenna110]

Btw do the earlier hydraulics have more or less travel? Or are the the same as the later models.

 

[pbgbottle]

Btw do the earlier hydraulics have more or less travel? Or are the the same as the later models.

I’m not sure I have always wondered about that. I know there was a post here on mud where a member was doing the research but I don’t think the results where ever finalized. I do know the 3spd slave cylinder or 71-74 ish years had a smaller bore which maybe combined with later master may increase travel. I have used a 1974 slave in the past with a 1978 master and it worked fine but the last slave I bought is also for 1978 year. And I can’t remember if I ever noticed a difference. If I ever need a slave again I’ll order the earlier slave this time and check it out for more or less travel. Also not sure if masters are different size bores
I’ll have to scan through the EPC and see what all the part numbers look like and cross reference the years. Cheers.

 

[atazman]

Here's what my research shows regarding clutch master and slave bore sizes:

Clutch Master and Slave Cylinder bore sizes for various FJ-40 years:
		Clutch Master Cyl.:​	inches​
		58-66​	1​
		66-1/75​	3/4​
		1/75-4/85​	3/4​
		​	​
		Clutch Slave Cyl.:​	inches​
		58-66​	7/8​
		66-74​	3/4​
		74-85​	13/16​
		​	​
		Brake Master Cyl.:​	inches​
		58-70​	1​
		70-74​	1​
		75-80​	1​

 

[avicenna110]

Here's what my research shows regarding clutch master and slave bore sizes:

Clutch Master and Slave Cylinder bore sizes for various FJ-40 years:
		Clutch Master Cyl.:​	inches​
		58-66​	1​
		66-1/75​	3/4​
		1/75-4/85​	3/4​
		​	​
		Clutch Slave Cyl.:​	inches​
		58-66​	7/8​
		66-74​	3/4​
		74-85​	13/16​
		​	​
		Brake Master Cyl.:​	inches​
		58-70​	1​
		70-74​	1​
		75-80​	1​

Thanks, how much does the bore size impact the amount of travel?

 

[atazman]

advicenna 110.............. if you tell me what master and slave bore sizes you are interested in, I can calculate the expected travel on the slave rod. If you go too large in master bore (like the 1" size) you could possibly push the piston of the slave cylinder out the back end if you are considering a smaller bore slave (like the 7/8" size).

 

[avicenna110]

Hi all again, I need a little help. I rebuilt the TC and installed it on the car along with the transmission. I installed the clutch the same way as before. The TC was working properly upon rebuilt. I start the car and the clutch doesn’t disengage (car doesn’t move).

The release bearing on the fork was difficult to get on the pressure plate, and I’m thinking the pressure plate was depressed slightly upon installation even with clutch not pressed. The clutch would release quite high before so I’m hoping it’s just the adjustment. How easily are you supposed to get the release bearing on the pressure plate and positioned?