Help with gmc hydraulic clutch
 

I’m trying to get a clutch working in a 63 305e with an sm420. Just bought this truck and replaced the master and slave cylinders but still no clutch. I read through the adjustment procedure in the service manual and it says that when the throw touches the fingers the wedge on the end of the rod should be about 1/4” away from the fork. So here’s the issue: when the throw out starts to touch the fingers on the pressure plate the rod will just barely reach the fork and there’s no travel left. I’ve pulled every thing out and examined it and I’m not seeing an obvious problem. The clutch is not new but it has plenty of material left and both the flywheel and pp appear to be fine. My only thought is that maybe the wrong throw out bearing was installed? The short one? But I’m not sure how this would have ever worked if that was the case. Any ideas?

Re: Help with gmc hydraulic clutch
 

Did you get all the air out? Bench bleed the M.C?

Re: Help with gmc hydraulic clutch
 

Yes. It’s not an issue with the hydraulic part of the system. It just looks like the pushrod at the slave is somehow too short, but everything appears to be what it should be. I don’t understand it.

Re: Help with gmc hydraulic clutch
 

Isnt the rod adjustable?

Re: Help with gmc hydraulic clutch
 

Hope this helps

Re: Help with gmc hydraulic clutch
 

I have that manual and by following that procedure when the rod is adjusted even all the way out, the throw out still isn’t contacting the fingers of the pressure plate. It’s about 1/4” shy. I can get it to start grabbing with the pedal about 2/3 of the way down but there’s just not enough travel to fully release it.

Re: Help with gmc hydraulic clutch
 

I’m stumped.

Re: Help with gmc hydraulic clutch
 

On 62 the rod was to inside mount on fork not outside