Engine/Transmission (1994 - 1998) Not Enough Clutch Pedal?

[MStearns]

Put a new clutch in my truck a few weeks ago when I swapped the NV4500 out for G56. And ever since I have been real close to not having enough clutch pedal to disengage the clutch fully and it starts engaging less than a 1/2 inch off of the floor. It's driveable. As a matter of fact as long as I'm careful it works fine... but when I don't think about it or get in a hurry the truck lets me know about it:-laf



A quick fix would be to simply lengthen the push-rod on the slave cylinder or work something out to make the rod on the master cylinder adjustable. I'm tempted to attack if from the bottom as adding a 1/4 " or so to the push-rod on the slave cylinder looks to be the easiest approach... but by cutting the master cylinder rod in half, threading both ends and adding a sleave I could more easily adjust it in the future.



Not sure which would be better



The Hyd system is still in good shape, no leaks or air, otherwise I would look at a new system.

 

[GCroyle]

Mark,



Can you prove with a test of the hydraulic system that in fact is does not have air?

 

[MStearns]

Actual, scientific proof there is no air is very difficult, for any hyd system. It is however still the factory set-up and has never been apart so there is no way air would have been introduced. There are no bubbles or any sign of air in the fluid.



I am also confident the fluid is not bleeding past the slave cylinder as I can hold the clutch to the floor all day long and I can move in and out of gear and the clutch never starts to engage. I just have to press hard into the carpet and padding which I never did before.



South Bend's clutch came with a spacer for the pivot ball to "aid in clutch disengagement" so this doesn't seem to be abnormal. I have also read that heavier after-market clutches can engage very early and sometimes need adjustments to the linkage. I haven't had a chance to call South Bend yet to see if they have a recommendation. With any luck I'll get that done on Monday.



It is obviously a little late to slip another spacer under the pivot ball as the transmission is already in and there is no inspection cover on the G56. But I could easily lenthen the slave cylinder's push rod a little.

 

[GCroyle]

Mark,



Sorry. Now that you have mentioned a brand name I cannot discuss further.



Good luck.



Gary

 

[MStearns]

Well that's a little silly... there are brand names all over these discussion boards.



Well, maybe we can just talk about the linkage and the slave cylinder:-laf

 

[NIsaacs]

Mark, to lengthen the slave cylinder rod will not help. It will just self-center again. Also, if it is too long it will bottom out and keep pressure on the clutch release bearing. Sounds like the throw is off for some reason. Either it has air in the slave or the new clutch needs more throw then the original.



I would work the slave back and forth several times. You will need to make sure the line is the highest part of the slave and make sure you bottom it out completely every time you cycle it. Leave the master alone, unbolt the slave and push the rod against the tire or something. Sometimes they are hard to push.



Nick

 

[GCroyle]

Mark,



I pay for my own membership but because I work for a clutch company and I consider it to be incorrect for me to comment on any other clutch brand once a name has been mentioned.



Good luck.



Gary

 

[MStearns]

Gary, I understand, no problems.



Nick, tried working the slave as you said with no change but I think I figured out the issue. I checked the distance between the mounting surface for the slave and the edge of the bellhousing (one of the few measurements I failed to check when swapping in the G56) and there is a 1/2 inch difference between the NV4500 and the G56.



So I am going to go ahead and lengthen the pushrod. I'll probably add a full 1/2 inch and then grinder her down until I get it to engage like I want

 

[MStearns]

It's better Not exactly like it used to be but definately better. It's difficult to measure, but adding the 1/2 inch to the push rod gained me approximately ~1/2 inch of pedal in the cab, maybe a little more or less. Regardless I don't have to crush the pedal into the firewall anymore. Utilizing my patented "When does the truck start to roll down the driveway test":-laf the clutch starts to disengage about an inch off of the floor now which is much better than only a 1/4 - 1/2 inch off of the floor so I'll take it!

 

[NIsaacs]

Okay, that makes sense, if the mounting surface is a half inch farther away.



You might check your push rod for the master cylinder where it attaches to the clutch pedal. They can wear bad and shorten your throw.



Scoot your seat forward



Nick

 

[MStearns]

At 6'4" I'm usually looking to get my seat as far back as I can

 

[fest3er]

At 6'4" I'm usually looking to get my seat as far back as I can

Take it out and sit in the back seat. :-laf