Clutch question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

knight61 · 01-24-2014, 10:56 AM

My 71 C20 truck clutch is very hard to press in. Is this a matter of a heavy spring on the linkage, or is it because of a truck clutch? The guy I bought it from had recently put it a new clutch and a four speed transmission. If it is not a matter of a lighter spring, are there ways to lighten up the clutch petal. I use the truck to plow my driveway and a parking lot and it is murder on my leg. Thanks.
Walt

geezer#99 · 01-24-2014, 11:05 AM

Could be the style of clutch. A borg&beck (B and B) 3 finger style is harder to push in compared to the standard diaphragm style found in most chevy's. B and B were used in heavier trucks. Look on your clutch fork. There might be 2 places to connect the push rod. Put it on the outer most hole.

motorcritter · 01-24-2014, 06:36 PM

Check for wear/excessive play at the pivots on the Z-bar. It doesn't take much misalignment to lead to a heavy pedal.

John Pasinski · 01-25-2014, 06:17 AM

http://www.ramclutches.com/clutch%20u/cl_u_1.htm
I have a C30 402 (now 413) w/ a 12" Borg & Beck clutch. Yes; B & B assy's were generally installed in the larger work trucks. They have tenacious holding power. Anytime the clutch is changed, the flywheel (if it's still servicable) should be turned as well.
I started with this article. Any misalignment whatsoever will make a mess of everything including the flywheel surface. It sounds like that's the problem you have.
The clutch shouldn't be as difficult as you're saying. Clutches were the connection long before A/T's. As a matter of fact, you can always modify w/ an hydraulic clutch if you really want to tinker with it.

68gmsee · 01-25-2014, 10:02 AM

If able to, ask the previous owner if he had a heavy duty pressure plate/clutch installed in it.

When I bought my 69 it had a heavy duty pressure plate/clutch in it and was also hard to depress. Driving it in the city was a pain. I installed a lighter 1/2 ton clutch in it and it helped a lot.

What is the truck primarily going to be used for?

Obviously the heavy duty one is preferable for towing, racing or snow plowing as in your case but if it's light snow removal work, a lighter clutch will work just fine.

knight61 · 01-25-2014, 10:37 AM

John,
I use it for light personal plowing with a snowsport plow. But mostly are using this vehicle to haul equipment I am scrapping from a defunct family knitting mill.
Usually carry about a ton at a time, but have already had a two ton piece loaded, but that was a one time event. This truck is a 3/4 ton or stake body type with a 292 six. I am looking at going the hydraulic route. Saw some posts about it, does not look too difficult. Being a six cylinder, there is plenty of room to work under the hood. I have the truck about five years and do not think I could find the last owner too easy. But I will consider the new clutch option, might be easier then concocting a hydraulic setup.

burnin oil · 01-25-2014, 01:00 PM

As said check the linkages. I bet the rod that connecs to the zbar is worn. I run a HD diaphram clutch and it is not all that hard to push. My dual disc hydraulic clutch in my 5500 takes more effort. If the linkages are not worn it could be out of adjustment. Trying to over extent the pressure plate fingers takes alot of effort. All my clutchs take about the same effort as the brake pedal with power assist.

01-24-2014, 10:56 AM	#1
knight61 Registered User Join Date: Mar 2010 Location: Reading, PA Posts: 11	Clutch question My 71 C20 truck clutch is very hard to press in. Is this a matter of a heavy spring on the linkage, or is it because of a truck clutch? The guy I bought it from had recently put it a new clutch and a four speed transmission. If it is not a matter of a lighter spring, are there ways to lighten up the clutch petal. I use the truck to plow my driveway and a parking lot and it is murder on my leg. Thanks. Walt

01-24-2014, 11:05 AM	#2
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,731	Re: Clutch question Could be the style of clutch. A borg&beck (B and B) 3 finger style is harder to push in compared to the standard diaphragm style found in most chevy's. B and B were used in heavier trucks. Look on your clutch fork. There might be 2 places to connect the push rod. Put it on the outer most hole.

01-24-2014, 06:36 PM	#3
motorcritter Registered User Join Date: Mar 2012 Location: Boulder, CO Posts: 350	Re: Clutch question Check for wear/excessive play at the pivots on the Z-bar. It doesn't take much misalignment to lead to a heavy pedal. __________________ If 'that which does not kill me, makes me stronger', then I should be Superman by now!

01-25-2014, 06:17 AM	#4
John Pasinski Registered User Join Date: Aug 2007 Location: orlando Posts: 456	Re: Clutch question http://www.ramclutches.com/clutch%20u/cl_u_1.htm I have a C30 402 (now 413) w/ a 12" Borg & Beck clutch. Yes; B & B assy's were generally installed in the larger work trucks. They have tenacious holding power. Anytime the clutch is changed, the flywheel (if it's still servicable) should be turned as well. I started with this article. Any misalignment whatsoever will make a mess of everything including the flywheel surface. It sounds like that's the problem you have. The clutch shouldn't be as difficult as you're saying. Clutches were the connection long before A/T's. As a matter of fact, you can always modify w/ an hydraulic clutch if you really want to tinker with it. __________________ A man's thoughts devise his ways; but it's GOD that directs his steps.

01-25-2014, 10:02 AM	#5
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Clutch question If able to, ask the previous owner if he had a heavy duty pressure plate/clutch installed in it. When I bought my 69 it had a heavy duty pressure plate/clutch in it and was also hard to depress. Driving it in the city was a pain. I installed a lighter 1/2 ton clutch in it and it helped a lot. What is the truck primarily going to be used for? Obviously the heavy duty one is preferable for towing, racing or snow plowing as in your case but if it's light snow removal work, a lighter clutch will work just fine. __________________ 68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive...

01-25-2014, 10:37 AM	#6
knight61 Registered User Join Date: Mar 2010 Location: Reading, PA Posts: 11	Re: Clutch question John, I use it for light personal plowing with a snowsport plow. But mostly are using this vehicle to haul equipment I am scrapping from a defunct family knitting mill. Usually carry about a ton at a time, but have already had a two ton piece loaded, but that was a one time event. This truck is a 3/4 ton or stake body type with a 292 six. I am looking at going the hydraulic route. Saw some posts about it, does not look too difficult. Being a six cylinder, there is plenty of room to work under the hood. I have the truck about five years and do not think I could find the last owner too easy. But I will consider the new clutch option, might be easier then concocting a hydraulic setup.

01-25-2014, 01:00 PM	#7
burnin oil Registered User Join Date: Jan 2013 Location: Eastern TN Posts: 1,921	Re: Clutch question As said check the linkages. I bet the rod that connecs to the zbar is worn. I run a HD diaphram clutch and it is not all that hard to push. My dual disc hydraulic clutch in my 5500 takes more effort. If the linkages are not worn it could be out of adjustment. Trying to over extent the pressure plate fingers takes alot of effort. All my clutchs take about the same effort as the brake pedal with power assist.



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