Clutch question, 1980 Jimmy

Got a 1980 Jimmy every so often the clutch refuses to work. By that i mean that the shift fork seems to wrk its way out of the bell housing. So for a
while I can use the clutch normally then one day i will walk out and nothing. Its a 350 motor (big suprise) with a Muncie 465 Trans. I have reached my wits end. its been apart and back together in my garage three times. What am i missing? The pedal travel seems strange but its been like that ever since i got the truck. By that i mean it is stiff and slow sometimes and the clutch seems to not have a firm lock up on the full rise of the pedal. I'm wondering if I am missing somthing that was not there to start with or perhaps i am doing wrong. I have tried to lube the pivot point under the dash and have adjusted the hell out of this with no real improvement. Does anybody have an idea or even a series of pictures of a correct set up? from the under car view thanks all mark W. snipped-for-privacy@nospaminfostations.com i will be out of the area but will look this NG up when i get back if you have any questions thank you all again
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Hi,     I'm assuming that you have a mechanical clutch. Is the trans a Muncie or a New Process? First, all shafts have a retaining device such as a bolt, screw, or detent (spring, ball bearing, and screw to keep it in place.) Is the fork shaft from the trans going into the clutch? This seems strange. Are we talking about the shift fork or the clutch fork? If a bolt or screw is coming out or loose you may want to use blue lock tight on the threads. Also try torquing any suspected bolts down. A good book for torquing specs is the Proto tool catalog. They have a complete reference towards the back.     If your clutch is not grabbing all the way your linkage is probably to tight. You should have about 1" of play at the pedal before you feel pressure. If it is a hydraulic system you need to bleed it.     Back tracking lets assume that your clutch fork (presses your throw out bearing.) comes loose or out of place. The fork is attached by a pivot and retaining spring (spring clip or other holding device). The retainer might even be a flat spring clip with a cutout to embrace the pivot. This is behind the fork. The Clutch fork should be securely attached to the pivot. The retainer clamps around the pivot. If the spring is not there or broken off than that is your problem. A loose clutch fork can do some strange things. When you remove the trans try grease lubing the input shaft at the bellhousing, but not to much. only a light coat as you don't want it to get in your clutch disc. I'd be willing to bet that it is the retaining spring on your clutch fork. You might have to put in a new clutch fork (if the spring retainer is missing). Sometimes they are rivrted on the fork back. Another sympton is lack of leverage at the clutch (hard to press down). Try going to a dealer and asking them and look at what a new one entails. Good luck to you. Jessie
Marko wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
thank you for your help, it is the clutch fork 9goes ito bell housing and encompasses the shaft pulls clutch in and out. It seems to be working its way out i will look for the spring that holds it in when i next take it apart. any suggestions about the stiff pedal. pedal is so stiff that even with no clutch in the truck the underdash spring will not pull it back.? thank you marko
i will be out of the area but will look this

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.