Technical Saginaw problems

I am have some serious problems with the Saginaw I have put in my truck and was wondering if anyone might have any ideas on a solution.

I have rebuilt the transmission so all new syncro's, bearings etc. It's been a while but I believe I put 75w90 gear oil in it. It was shifting fine on the bench before I put it in the truck. Last week I got the truck ready to back out of the garage for the first time. I had it up on jack stands and wanted to check the transmission with the wheels off the ground first and I found and it wouldn't go into reverse. Then the transmission started having issues shifting into gears with the vehicle not running. It would shift between 1st and 2nd, but wouldn't shift into 3rd but will shift into 4rd. It also wouldn't shift into reverse without a lot of force. If I turned the wheels I could get it to shift between 1st, 2nd, 3rd and 4th with no issues but then it will not go into reverse.

I pulled it out, opened it up and saw no problems. I put it back together and tested it on the bench. It seemed to shift with no issues. I reinstalled it in the truck and tried again without the truck running, shifted without issue. Once I reinstalled the driveshaft and rotated the wheels while doing so it was back to doing the exact same thing. It seems to do the same thing with or without the the shift linkages on.

I talked to Squirrel and he suggested that sometimes old transmissions won't go into gear easily when not running so I tried it again with the transmission running. Shifted through all the gears without issue with the truck running. Thinking I had solved the problem I put everything back together put the truck back on the floor, go to back it out and won't shift into reverse again running or not.

Help please getting super frustrated!

 

When trying to go into reverse is your clutch pedal fully depressed? If so have you tried to slowly release the clutch and see if it will go into gear? My 64 will not shift correctly if the clutch is fully in and it kicked my butt for three transmission removals.

 

Yes it is I will try and see if that makes a difference. Thanks for the suggestion.

 

Won't go into reverse .
It grinds when you try ?
It won't grind ?
If it grinds its clutch or trans .
If it won't grind its probably shifter .

 

I had similar issues when I put my saginaw 4 speed in my coupe. Turned out I needed to adjust the clutch just a hair more as it had some slight drag. Once I did that, all was right with the world.

 

Won't go into reverse running or not at this point. It grinds when running.

 

I would look at clutch adjustment.

was the flywheel machined.
When I worked in automotive the machine shop we used would sell us a flywheel shim to bring the flywheel back out the amount it was machined.
Clutch fork adjustment?
Pedal adjustment?

 

you didn't mention this, and I forgot to ask...

oops

 

Thanks for all the suggestions I will go through everything again and report back.

 

I don't expect this to be the problem but make sure you use a trans lube with a GL-4 rating.

 

Pilot bushing to tight?

 

Yeah I just read that online mine say it is rate for both so I am going to assume that means it's not really a GL-4.

 

GL-4 is not readily available like it was in the past, got some a few years back for my Muncie at NAPA, made by Sta-Lube.

 

I wouldn't worry too much about the gear oil....but see about that clutch

 

Well I think I figured out my problem and I may be fucked. My master cylinder is too small and I don't have room to put a bigger one in so unless I can find a 5/8" bore push style slave cylinder or a super compact master with a bigger bore I am not sure what I am going to do. The manufacturer of the clutch pedal unit changed specs after I bought mine and I was going on the assumption that it was the same as what they are currently selling when I put the system together.

 

Ok so your not getting enough stroke ?

Can you take a pic of the slave and pushrod setup ?

ive made longer pushrods one the past (from the slave to the clutch fork ) to get a bit more stroke and have the clutch release correctly.

 

Not sure if I can get a good picture or not I will try but it is this cylinder going straight into the clutch fork.

My pedal is bottoming out before I get full extension of the slave.

 

Kind of a shitty picture but this is it.

Sent from my SM-G950W using The H.A.M.B. mobile app

 

can you find a larger bore master cylinder?

 

Not that I can find that will fit. I need the body to be 3 1/4" long max and plumbed from the side. I have zero space to go any farther forward without major modifications.

 

It’s a cheap kinda cheat way to do it
But can you lengthen the push rod ?

like I’ve said, done it in the past with success. At least it’ll get you up n running until you can source the correct master.

might want to look at fork lift masters, most are very short with one port.

 

What push rod? On the pedal?

 

It looks like there is plenty of thread on the slave cylinder pushrod to run it out another
3/4'' towards the fork.
That will give you more stroke.
KK

 

There is no room for the throw out bearing to go any farther forward. I have it as far forward as I can without it touching the pressure plate springs.

Just so the set up is clear as the picture isn't great. It's a push style cylinder that is adjusted so the it is touching the fork and as mentioned the fork is pushed as far as it can go. I have the rod on the pedal as long as it can possibly go which has the clutch pedal sitting about an inch higher than the brake at the moment and the pedal hits the floor.

 

I had a similar problem way back, so I had my friend at Allied Auto Parts look up master cylinders with larger bores...(had a 1", needed 1-1/8")
Friend Dave found a M/C for a different model, with 1-1/16" bore...I took the works to my machinist, and he bored out the M/C, fitted the guts of the larger one and problem was solved.
(Oh, the 'problem' was the customer's M/C was chrome plated, and he didn't want to change it!)

 

Thanks I may have to look into that. My only concern is the body of this one is so short I am not sure what would work.

 

I was talking about the pushrod from the slave to the clutch fork.
But if your already at max adjustment then I dunno.


You could still try it to confirm what we are thinking and come up with a game plan from there.

what @Atwater Mike mike posted might be your only solution if you can’t find a larger boat master to fit your specs.

 

If the TO bearing is going as far forward as it vcasn without hitting the springs and is not releasing , then what good will more stroke do you ?
You either have a tight pilot ?
A faulty clutch ?
The disc in backwards ?
If you start the car in gear , do you feel it surge a bit forward/ reverse when the engine first turns over ?

 

I don' think it is. That's the problem. The slave is not pushing far enough to fully disengage it. Because of the mismatched cylinder sizes I don't have enough pedal movement to fully extend the slave cylinder. When I had it up on stands I could put it in first with the clutch in no wheel movement let the clutch out they would turn.

 

The slave that comes from the factory with this master setup is 3/4". That is only 1/16" smaller than what I have in there now. Would it make enough of a difference to try one of those slaves? They are easy to get and cheap but I would probably have to make a new bracket, which is not a big deal but not going to waste my time if it will make no real difference.