Transmission won't go in gear

#1

I could use some help with the transmission on my track car. When I last drove my car, about a year ago, my TOB rattled a bit in neutral, but never with the clutch depressed and I never had problems shifting. After sitting for a about a year with the nose at a slight uphill incline due to my driveway, the clutch would not rebound on its own and the car would not go into gear when engine was running.

I replaced the clutch master and slave cylinders and bled them. A friend confirmed that the shaft on the slave was moving and the clutch pedal now rebounds on its own and feels like it has proper tension. Unfortunately the car will still not go into gear when running. I can shift through all gears with the engine off. I did a hill test with the car in gear, no brakes, and clutch pedal depressed, but the car did not move. If I try to start the car in gear, even with clutch pedal depressed, the car lurches forward. When idling in neutral, I do not hear the TOB rattle anymore.

Clearly the clutch is not disengaging, but why? Is there anything short of dropping the transmission I can do?

#2

It sounds like you didn’t get the slave cylinder bled properly or the replacement was bad. To bleed properly, you need to remove the clutch slave cylinder from the transmission and hold it with the bleed screw pointing up. It’s easy to bleed with a power bleeder hooked to the master cylinder, but you’ll need to fab up something to keep the piston and rod from ejecting.

If bleeding the system doesn’t help, you might have a travel issue. A longer rod might help. 3/8" small block pushrods work great to make your own pushrod.

There is no reason to remove your transmission. The problem is definitely with your clutch hydraulic system. Its kind of frustrating, but some replacement slave cylinders just don’t work well. It could be a piston size issue or just poorly made unit as well.

#3

I’m with Rich. Sounds like you’ve an air bubble in the clutch slave.

I always have lots of problems bleeding clutch slaves. Google around and read carefully the various tricks to getting it done. I’ve tried and failed at pretty much all of them. For the life of me I’ve not been able to figure out why I couldn’t get the various techniques for clutch bleeding to work. The only way I’ve succeeded is what Rich described. With the slave removed from the tranny, by laying alongside of it, put the slave in a fixture to prevent the rod from blowing out. Invert the slave so the bleedvalve is at the top. Have an asst in the car on the clutch pedal and do a standard brakebleed.

You can fab a longer push rod using an old screwdriver, but I wouldn’t. That’s a ghetto fix for when you have a problem with too short of a pivot pin or thrust bearing. I think your problem is an air bubble in the slave.

#4

Uh…NO!!! Clutch disk has attached itself to the flywheel. Bump start down hill, push clutch in, and blip motor. Should unstick. If not, its new clutch time.

#5

Ok, I think I’ll troubleshoot as follows:

  1. Re-bleeding as proposed and/or from the bottom up;
  2. If re-bleeding doesn’t work, replace slave again;
  3. If that doesn’t work, try to bump start with key

I will let you know how it goes . . .

#6

Chuck,

I helped the OP with the installation and bleeding of the new master and slave cylinder. Agree with other responders that first step is to double check the system is properly bled in hopes of avoiding having to drop the tranny. Always start with the simple things, right?

The clutch won’t disengage to allow the car to roll with the clutch depressed. Thus, I’m not sure how we could bump start it as you suggest.

#7

That would be the only option other than dropping the trans. It should roll in neutral, so get it rolling with the motor running and mesh whichever gear will go. Then try to break loose.

#8

[quote=“Higgt00l” post=80889]Ok, I think I’ll troubleshoot as follows:

  1. Re-bleeding as proposed and/or from the bottom up;
  2. If re-bleeding doesn’t work, replace slave again;
  3. If that doesn’t work, try to bump start with key

I will let you know how it goes . . .[/quote]
I don’t see anything here that would tempt me to replace the slave.

#9

My first thought was the same as Chuck’s. Do his solution first. It will take 5 minutes and requires no actual work.

#10

By way of update, this is my progress so far . . . I let the car sit on an incline (driveway) for 3 weeks and 3 days because I was too lazy/busy to work on it. Bought an oil can to do a reverse flush. Before starting work, I thought I’d see if I was still having problems. So I started the car and it works fine now. The three week ignore the car/incline bleed with no actual work did the trick! Thanks for the help.