Tranny won't go into gear.

[1lo620]

Ok so been redoing my 79 620 I just picked up. So I did a new clutch and throw out bearing. All seemed fine been driving the truck for about 2 weeks. Then all of a sudden it seemed like I lost my clutch. Thought is was slave cylinder bit it seems good. Bled it again. That was ok...any idea of what is going on. 

[datzenmike]

I assume it goes into gear with the engine off?

 

Have someone work the clutch pedal while you look at the slave push rod and the clutch arm. It should move just over an inch. Does it?

[1lo620]

Yes they do. My wife does the pedal while I bleed it. It moves fine. And no air in the bleed line. And to be honest the pedal seem to loose a bit of the tension in the pedal if that makes sense. It is the same set engine and tranny I had in my 74 chop top. L18 with Z 5spd never had any issues with it. Then I changed clutch while I had engine out. And all seemed fine until last couple of days. 

[datzenmike]

Externally the clutch should disengage. Transmission has to come out and because the last thing changed was the clutch and pressure plate, I would start with it.

[pidge]

Linkage to the shifter perhaps? 

[datzenmike]

Goes into gear with engine off.

[420n620]

To be sure the clutch at the slave cylinder is properly working, the movement at the clutch fork has to move 1 3/4" or was it 1 1/4". I'll have to check my Datsun book to be sure. Measure it to be sure. Guessing or assuming is not a option, lol  If that's good, check the tranny fluid (G4). I say that cause you didn't mention that you checked the fluid level. 

My 78 620 I bled 2 qts through the system, after installing a new clutch set,  it's still not working, that was 9 yrs ago. Been hoping someone on the form can come up with a solution since this isn't the first time I've read this happening on a Datsun.   

 

[banzai510(hainz)]

1 hour ago, 420n620 said:

My 78 620 I bled 2 qts through the system, after installing a new clutch set,  it's still not working, that was 9 yrs ago. Been hoping someone on the form can come up with a solution since this isn't the first time I've read this happening on a Datsun. 

This cant be that hard to figure out.

maybe the Master is bad. My master in in my toyoya brakes was bypassing the cylinder and only had front brakes I think. It never lost any fluid at all. I swapped and was good.

 

Key is was all the parts the same when you installed it?? exactly the same.

 

1low620  push the clsut and see if the lever moves at the slave?  yes NO?

Edited April 19, 2021 by banzai510(hainz)

[datzenmike]

I suggested looking at the arm for movement, he said he checked it. Slave travel is 1.18" so clutch arm will be the same.

[420n620]

On 4/19/2021 at 7:19 AM, banzai510(hainz) said:

This cant be that hard to figure out.

maybe the Master is bad. My master in in my toyoya brakes was bypassing the cylinder and only had front brakes I think. It never lost any fluid at all. I swapped and was good.

 

Key is was all the parts the same when you installed it?? exactly the same.

First time I've had a problem bleeding a slave cylinder, done several in the past with no problems. I did try another clutch master and slave that I know are good and still didn't get the slave to move far enough to allow the trans to engage.

Talked to H2izzo aka Tim Dalby when I was at Dave Pattersons wake. He mentioned a high spot in the clutch line on the firewall might be the the problem. Not sure if that's where the problem is. 

I'm going to look into back flow bleeding but not 100% sure how yet, plus I don't want brake fluid on the paint in the engine compartment. Need a way to recover the fluid.

 

On 4/19/2021 at 10:06 AM, datzenmike said:

I suggested looking at the arm for movement, he said he checked it. Slave travel is 1.18" so clutch arm will be the same.

That's what I found also. Stroke 30mm, 1.18 or 1 7/32. Mine only move 3/4", so I definitely got air in the line for sure. 

 

1lo620 did you get it to work ? 

[datzenmike]

3/4" won't do. Check it. 1.18" is the manual number.

[banzai510(hainz)]

I had a clutch master not work right.

I put my finder in there and pluged the hole in the resivoir while someone pump the pedal then it worked fine again. I dont know why but it worked

[datzenmike]

Maybe air trapped and you jogged it loose.

[420n620]

On 4/20/2021 at 3:06 PM, 420n620 said:

 

1lo620 did you get it to work ? 

have any luck fixing your clutch ?