CK5
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Clutch fork throw measurement *fixed*

I also stayed at a Holiday Inn express last night.:D

ya thats cool but tom bodett will leave the light on for ya .

i used a cheepo chine clutch and flywheel for a few years. plowed snow / played offroad / beat it up few times / even had burnt smell out of it bad 1 time. pulled it when i went auto and looked great and only 2-3 tiny burn spots on flywheel.
 
When I had my '72 K5,I swapped a SM465 into it after the TH350 gave grief,and I went thru 2 Borg-Warner 3 fingered pressure plates in less than a month,in normal city/highway driving..both had one finger fail,and the clutch refused to release...the first time it failed I was at a red light,and a red corvette was in front of me..had my foot holding the clutch pedal to the floor,in second gear,waiting for the light to turn green,when suddenly the truck lurched forward and bumped the vette!..:eek:..thought the guy was going to kill me,but no real damage was done to his car,so he just vented his displeasure and I tried explaining how the clutch must have failed,showed him with the truck in gear and the pedal depressed,it still wanted to move when I cranked it over..........................................................................................................................................................................................................I busted a$$ that weekend installing another B-W rebuilt,had to drive 80 miles to my parents house to do it,rent a tranny jack,and have it buttoned up to drive back to work monday AM...wasn't 3 weeks later when that pressure plate did the same thing,but not as suddenly...at first I had a hard time getting it in gear without clashing,then it eventually dragged so bad I could smell it burning at red lights,and adjusting it made no difference............................................................................................I ended up using a USED 11" centerforce clutch setup a friend had in a camaro that he totaled,that had only 1500 miles on it...never had any troubles with it..I was going to go with a 12" diaphram pressure plate so I could re-use the disc I already had,but I got the whole 11" setup for 50 bucks,so I went with that instead.....................................................................................................I must say the difference in pedal pressure was so great between the 3 finger PP and the Centerforce,that it felt like I'd put a hydraulic clutch in ,I practically dented the floor pan the first time I went to put the pedal down!...we had several of those B-W 3 finger pressure plates go bad in a short time at the parts store I worked at,swore I'd never use another rebuilt Borg-Warner clutch again..........................................................................................................................................................................................................Far as I remeber,they listed 3 different throwout bearings...the N1488 one was the shortest,it was used with most 3 fingered pressure plates...the N1716 one was the "medium" length one used on raised digaphram pressure plates,and there was another number I cant recall that was the longest one,used on flat digaphram pressure plates,mostly on 6 cylinder applications--I think they all had the same outer diameter where the contact the pressure plate but I could be wrong...I only know this because I had to take the Tremec 3 speed out of my 75 2wd Blazer 3 times,before i got the right throwout bearing in it!--the "kit" I bought came with the wrong one,and I couldnt adjust the free play right with the bearing the BCA book listed for the truck...but I had put a Vega saginaw 4 speed in it,maybe that was why I had the problem..
 
I can check the throw on mine as soon as I get home.
I'm on the ship right now but I should be home by 6PM Pacific

Thank you kind sir.
This has been my sit and stare view for the day-

IMAG0135.jpg


I can tell you that method is overrated, my clutch still hasn't disengaged.
I'm in humble mode and ready to hear any possibilities I may not be considering.
 
Clutch won't disengage so not to many options.

Wrong throw out bearing.
Bent clutch fork.
Pivot ball is broken or otherwise damaged.
Slave cylinder rod is too short or improperly adjusted. (if adjustable.)
Air in the line.
Line is fubar and swelling or leaking or both.
Master cylinder is leaking internally.
Low fluid.
Push rod to the pedal is bent. (had this one once, in Moab actually.)

That's all I can think of.
 
Clutch won't disengage so not to many options.

Wrong throw out bearing.
Bent clutch fork.
Pivot ball is broken or otherwise damaged.
Slave cylinder rod is too short or improperly adjusted. (if adjustable.)
Air in the line.
Line is fubar and swelling or leaking or both.
Master cylinder is leaking internally.
Low fluid.
Push rod to the pedal is bent. (had this one once, in Moab actually.)

That's all I can think of.

Your list is perfect! I have gone thru all of them... 3-4 times. T O bearings, which I have 2 are the only thing im uncertain of. Having said that, I find zero options in my searching for those. The hydro system I got was complete, 465/208 (didn't use those) Bell/fork/pivot ball (so unscathed it seems obvious it came from a low mile rig) and TO bearing which I have an identical new one. Made a rod 1/2' longer (not adjustable) to try as well. Bench bled the master/slave (slave is new), pedal is firm (consistent 3/4" throw, ZERO spongy feel etc...). My fork shows no signs of being bent, its design seems like it would be obvious? I will wait for readymix's measurement before I yank anymore teeth out of my mouth, the throw im getting must mean something? If his is different I will explore the bent fork theory, or start looking at my actual CF clutch (which I pulled from a running (my) rig as having under 500 miles on it. Wow, sorry for a the ( ).
Thank you Kurt, I really appreciate the options you've listed.
 
I will add that this CF clutch came off my 396. I purcashed a new Zoom flywheel for my 350 and mic'd them both. There was only a 1/16" difference so "I" think its safe to say that's not an issue fwiw.
 
Yeah, the clutch fork you'd probably notice with the stamped steel design. They're pretty tough to. I doubt that's it, just throwing it out there as a possibility.

Don't discount the master leaking internally. Had this issue and boy was it mind boggling as to the issue. Also had a line that sucked air but showed no visible fluid leakage.

You'll figure it out. Sounds like you've taken a step back from it, probably a good idea. Good time to tinker with something else and let it roll around in the back of your mind for a few minutes.
 
I will add that this CF clutch came off my 396. I purcashed a new Zoom flywheel for my 350 and mic'd them both. There was only a 1/16" difference so "I" think its safe to say that's not an issue fwiw.

1/16" = .0625" and is a HUGE number when dealing with a hydraulic clutch. I'm pretty sure I no longer have my AERA flywheel/clutch book from when i owned my shop but I remember it saying that you could not machine the flywheel on a hydraulic clutch more than something like .020" or you would end up with the clutch not dis-engaging.
 
Yeah, the clutch fork you'd probably notice with the stamped steel design. They're pretty tough to. I doubt that's it, just throwing it out there as a possibility.

Don't discount the master leaking internally. Had this issue and boy was it mind boggling as to the issue. Also had a line that sucked air but showed no visible fluid leakage.

You'll figure it out. Sounds like you've taken a step back from it, probably a good idea. Good time to tinker with something else and let it roll around in the back of your mind for a few minutes.

Ya know, the only thing I haven't addressed is the master. Kinda got locked in on the consistent 3/4" throw it gives me.
Thanks again, im sweeping/cleaning shop... cracked a cold one and the sun is shining here in the PNW :D
 
1/16" = .0625" and is a HUGE number when dealing with a hydraulic clutch. I'm pretty sure I no longer have my AERA flywheel/clutch book from when i owned my shop but I remember it saying that you could not machine the flywheel on a hydraulic clutch more than something like .020" or you would end up with the clutch not dis-engaging.

What? Seriously? What? My new flywheel is the thickerer of the 2... Im hitting the river for some Salmon, the run is getting thru the indian nets right now :D
 
Im certainly no machinist but... wouldn't this 1/2" longer rod more than make up for an out of spec (1/16th) flywheel?
IMAG0137.jpg

Thanks again for everyones help/insite... off to RIP SOME LIPS!
 
I don't remember the ratio on the fork. A 1/2" longer would surely seem to be enough and possibly to much.
 
1 tiny air bubble killed me for hr's till i removed the whole system from truck and bench blead it all upside down with another guy to get that bubble out . then perfect . :D
 

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