Replacing clutch on 3500 HD diesel 94

dspabout · 08-23-2008, 08:48 PM

Hello
Any suggestion where I can find details on how to change the clutch on this 94 3500 manual diesel chevy?
With the engine off I can shift gears but when the engine is running cannot change other than a rough rear. Pedal feels ok, no leaking on line, master. We figured that the clutch is worn totally after driving with stuck rear breaks for about 5 miles.

Thanks

brad4eva · 08-23-2008, 10:57 PM

Get a Haynes book on the truck

leolkfrm · 08-24-2008, 01:48 PM

sounds like you destroyed the throwout or pressure plate, Will it power shift once you are moving?

dspabout · 08-25-2008, 06:00 AM

Its a manual transmition.

leolkfrm · 08-25-2008, 06:07 AM

Yes it is! Thats why I said pressure plate (holds the clutch plate against the flywheel) or throwout (located in the clutch fork) If it was a big truck it would be the clutch brake.

hotrodpc · 08-27-2008, 12:28 PM

Am I out of bounds here? But it would seem to me if you can drive it without it slipping, and just can not change gears, that it is not disengaging. If I recall, that is a hydro clutch. If it is not slipping, I would think the clutch disk and pressure plate are OK. It could still be a master or slave cylinder even though the pedal feels OK. I would have someone push the pedal to the floor for you, get underneath and watch the clutch fork to see the travel. If the fork is not traveling far enough, I would suspect slave cyl. Although, I do not recall if the slave is external or internal. Likley external on a 3500 would be my guess. BTW, use someone trustworthy, not a child or your ex wife, and chock the wheels before you get underneath it. You should be able to do that without the engine running if the clutch is not power assisted.

hotrodpc · 08-27-2008, 12:32 PM

Here may be a better way test disengagement. Park on hill with the truck in granny low or reverse and NO E brake on. Shut it off. With it in gear it should hold on the hill. Push the clutch in, if it does not roll back and it is still holding, then it is in your hydraulic system not disengaging your clutch at the pressure plate. Just another suggestion.

leolkfrm · 08-27-2008, 07:40 PM

Yep I would agree on the slave cyl bypassing fluid within itself, If it has one

hotrodpc · 08-27-2008, 08:26 PM

Yep, that is exaclty what I am thinking leo. And it would still give some pedal feel being it is still pushing the fork/throwout brng to the pressure plate. Just a weak piston seal and some of the fluid is bypassing the piston within the slave.
I have driven many work trucks back to the shop without a clutch pedal. It really isn't hard to drive a manual trans using the clutch only to start and stop, if you are gentle with it and can find the RPM range by ear and feel. It is just hard on the starter when you have to start it in gear taking off from a red light. Also remember you still have to push the clutch pedal down anyway to activate the clutch safety starter switch.

hotrodpc · 09-02-2008, 01:50 PM

So what was the issue here? Did you ever get it fixed? Maybe he did what I said not to do. He let his ex wife test the clutch while he was under it and she ran him over.

08-23-2008, 08:48 PM	#1
dspabout Junior Member Join Date: Aug 2008 Posts: 8	Replacing clutch on 3500 HD diesel 94 Hello Any suggestion where I can find details on how to change the clutch on this 94 3500 manual diesel chevy? With the engine off I can shift gears but when the engine is running cannot change other than a rough rear. Pedal feels ok, no leaking on line, master. We figured that the clutch is worn totally after driving with stuck rear breaks for about 5 miles. Thanks

08-23-2008, 10:57 PM	#2
brad4eva Senior Member Join Date: Apr 2008 Location: Tennessee Posts: 433	Get a Haynes book on the truck __________________ //B-rad

08-24-2008, 01:48 PM	#3
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	sounds like you destroyed the throwout or pressure plate, Will it power shift once you are moving? __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

08-25-2008, 06:07 AM	#5
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	Yes it is! Thats why I said pressure plate (holds the clutch plate against the flywheel) or throwout (located in the clutch fork) If it was a big truck it would be the clutch brake. __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

08-27-2008, 07:40 PM	#8
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	Yep I would agree on the slave cyl bypassing fluid within itself, If it has one __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

08-25-2008, 06:00 AM	#4
dspabout Junior Member Join Date: Aug 2008 Posts: 8	Its a manual transmition.

08-27-2008, 12:28 PM	#6
hotrodpc Senior Member Join Date: Jul 2008 Location: OKC, OK Posts: 3,145	Am I out of bounds here? But it would seem to me if you can drive it without it slipping, and just can not change gears, that it is not disengaging. If I recall, that is a hydro clutch. If it is not slipping, I would think the clutch disk and pressure plate are OK. It could still be a master or slave cylinder even though the pedal feels OK. I would have someone push the pedal to the floor for you, get underneath and watch the clutch fork to see the travel. If the fork is not traveling far enough, I would suspect slave cyl. Although, I do not recall if the slave is external or internal. Likley external on a 3500 would be my guess. BTW, use someone trustworthy, not a child or your ex wife, and chock the wheels before you get underneath it. You should be able to do that without the engine running if the clutch is not power assisted.

08-27-2008, 12:32 PM	#7
hotrodpc Senior Member Join Date: Jul 2008 Location: OKC, OK Posts: 3,145	Here may be a better way test disengagement. Park on hill with the truck in granny low or reverse and NO E brake on. Shut it off. With it in gear it should hold on the hill. Push the clutch in, if it does not roll back and it is still holding, then it is in your hydraulic system not disengaging your clutch at the pressure plate. Just another suggestion.

08-27-2008, 08:26 PM	#9
hotrodpc Senior Member Join Date: Jul 2008 Location: OKC, OK Posts: 3,145	Yep, that is exaclty what I am thinking leo. And it would still give some pedal feel being it is still pushing the fork/throwout brng to the pressure plate. Just a weak piston seal and some of the fluid is bypassing the piston within the slave. I have driven many work trucks back to the shop without a clutch pedal. It really isn't hard to drive a manual trans using the clutch only to start and stop, if you are gentle with it and can find the RPM range by ear and feel. It is just hard on the starter when you have to start it in gear taking off from a red light. Also remember you still have to push the clutch pedal down anyway to activate the clutch safety starter switch.

09-02-2008, 01:50 PM	#10
hotrodpc Senior Member Join Date: Jul 2008 Location: OKC, OK Posts: 3,145	So what was the issue here? Did you ever get it fixed? Maybe he did what I said not to do. He let his ex wife test the clutch while he was under it and she ran him over.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
94 3500 diesel manual with chevron tow wont shift got stuck on Rear	dspabout	Chevy Truck Forum	4	08-23-2008 11:44 AM
Dodge 3500 Diesel Dually	jw7128jw	Dodge Truck Forum	4	05-11-2008 03:46 PM
Thinking of buying 1993 3500 diesel - need help.	Catsailor	GMC Truck Forum	1	11-24-2007 05:46 PM
Replacing the Clutch	John_and_Donna	Chevy Truck Forum	2	08-20-2006 03:45 PM
replacing the fan clutch	teampenner	Chevy Truck Forum	0	07-17-2006 03:51 PM