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-   -   1972 C10 clutch fork and clutch linkage issues (https://67-72chevytrucks.com/vboard/showthread.php?t=708317)

steviemack 05-28-2016 10:52 AM

1972 C10 clutch fork and clutch linkage issues
 
Purchased a new clutch fork boot and clutch rod boot.

I know where the fork boot goes but where does the clutch rod boot go? The LMC diagram does not show where it goes. I also noticed that mine is missing the clutch fork return spring. Where does it go? It seems to be working just fine without it.

Also in looking at the clutch linkage diagram it appears that someone has taken the pushrod "wing" nut and placed it behing the clutch fork and then just put a regular nut on the end. Is this correct?

dave`12 07-15-2016 02:19 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
A little late, but I will try to help as I'm working on the same stuff:

The wing nut is correct, mine has one as well, though a photo of yours would help, as there is no nut between the fork and the wing nut. In fact, the fork is grooved to accept the wing nut, a regular nut would be wrong.

I'm trying to figure out how to but my spring back, will have a pic in my thread when I do. Here is a link to the thread. It has a good diagram of the linkage that should help you.
http://67-72chevytrucks.com/vboard/s...clutch+linkage

steviemack 10-16-2023 12:45 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
1 Attachment(s)
Quote:

Originally Posted by dave`12 (Post 7654212)
A little late, but I will try to help as I'm working on the same stuff:

The wing nut is correct, mine has one as well, though a photo of yours would help, as there is no nut between the fork and the wing nut. In fact, the fork is grooved to accept the wing nut, a regular nut would be wrong.

I'm trying to figure out how to but my spring back, will have a pic in my thread when I do. Here is a link to the thread. It has a good diagram of the linkage that should help you.
http://67-72chevytrucks.com/vboard/s...clutch+linkage

HELP: So this so called push/fork rod wing nut is not threaded. Does it go on the front side of the clutch fork or back side? Either way, it appears that the push rod will require a regular nut on the very end, correct?

72SB 10-16-2023 10:33 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
2 Attachment(s)
the wing part goes on front side of fork and nut on back side. Return spring goes to DS frame rail and clips in hole

Leave the rear nut lose so the fork does not bind on the wedged spacer on the front side of it

LockDoc 10-16-2023 11:00 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Quote:

Originally Posted by steviemack (Post 9250986)
HELP: So this so called push/fork rod wing nut is not threaded. Does it go on the front side of the clutch fork or back side? Either way, it appears that the push rod will require a regular nut on the very end, correct?


The rod at the clutch arm on some of them doesn't have threads. (unless it has been replaced) That wedge piece that everyone calls a "nut" isn't really a nut because it doesn't have any threads in it, it just slides onto the end of the rod. The long spring holds it all together. The spring goes from the end of the clutch arm to a hole in the bottom frame rail.

LockDoc

kwmech 10-16-2023 11:17 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
I think all the nut was for was to keep from losing the wedge if the linkage somehow came apart.

steviemack 10-16-2023 11:23 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Quote:

Originally Posted by 72SB (Post 9251103)
the wing part goes on front side of fork and nut on back side. Return spring goes to DS frame rail and clips in hole

Leave the rear nut lose so the fork does not bind on the wedged spacer on the front side of it

Awesome, thanks for the quick reply. One more question, so to reduce the play in the clutch, do you move the swivel piece forward thus shortening the amount of thread on the end or backwards towards the fork thus increasing the amount of thread on the end?

I moved the swivel forward and then I could not get it back in the hole to secure it with the carter pin. Therefore, I have to remove it from the fork and discovered this issue with the placement of the so called push rod wingnut.

kwmech 10-16-2023 11:29 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Linkage adjusts on the other end of the linkage with the 2 jam nuts. Further adj (if absolutely needed) can be made by putting a few washers under the wedge. Adjustment is made by controlling clutch pedal end play inside the cab.

Southcity 10-16-2023 12:17 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
where does the clutch rod boot go?

On/at the firewall where the clutch rod passes through to interior.

steviemack 10-16-2023 12:36 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Quote:

Originally Posted by kwmech (Post 9251127)
Linkage adjusts on the other end of the linkage with the 2 jam nuts. Further adj (if absolutely needed) can be made by putting a few washers under the wedge. Adjustment is made by controlling clutch pedal end play inside the cab.

Thank you. I am assuming you loosen the two jam nuts and move the swivel piece forward thus reducing the amount of threads on the front end. When you say putting a few washers under the wedge are you referring to in between the wing nut and clutch fork itself?

kwmech 10-16-2023 09:14 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Under the wedge up against the step in the rod. Forget about the nut on the end, it has nothing to do with adj... Wedge rides against the fork with the spring holding it together ---nothing in between the 2

steviemack 10-17-2023 09:23 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
1 Attachment(s)
Quote:

Originally Posted by kwmech (Post 9251264)
under the wedge up against the step in the rod. Forget about the nut on the end, it has nothing to do with adj... Wedge rides against the fork- nothing inbetween the 2

Thank you again. So you are saying to put a washer or two between the wedge and the flange/stop on the push rod. See picture. However, in order to do this it will require adjusting the swivel on the opposite end between the jam nuts in order to get the push rod back in. Correct?

Just getting the wedge back in the correct location has made a bit difference.

72SB 10-17-2023 11:13 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Quote:

Originally Posted by steviemack (Post 9251410)
Thank you again. So you are saying to put a washer or two between the wedge and the flange/stop on the push rod. See picture. However, in order to do this it will require adjusting the swivel on the opposite end between the jam nuts in order to get the push rod back in. Correct?

Just getting the wedge back in the correct location has made a bit difference.

OP, look at my pic in post 4. I have a 1/4" spacer between the ridge of rod and wedge. This is because without it there were not enough threads on end of rod to draw the rod/wedge against the fork. I bought the wedge because mine was missing, and it is shorter than what is shown in factory manual I also posted in #4. You don't want the wedge tight against fork, just enough so the wedge stays engaged to fork recess. You otherwise adjust the rod shorter or longer to make pedal clutch engagement closer or higher off the floor

pjmoreland 10-17-2023 12:11 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
1 Attachment(s)
Here's the pedal pushrod boot on the firewall.

steviemack 10-17-2023 03:37 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Quote:

Originally Posted by 72SB (Post 9251436)
OP, look at my pic in post 4. I have a 1/4" spacer between the ridge of rod and wedge. This is because without it there were not enough threads on end of rod to draw the rod/wedge against the fork. I bought the wedge because mine was missing, and it is shorter than what is shown in factory manual I also posted in #4. You don't want the wedge tight against fork, just enough so the wedge stays engaged to fork recess. You otherwise adjust the rod shorter or longer to make pedal clutch engagement closer or higher off the floor

Thanks. This is excellent information that I have been troubleshooting for years. Now I have noticed that when we had the clutch replaced 30 years ago that the POS shop failed to reinstall the transmission cross member. I am assuming this is pretty important?

kwmech 10-17-2023 04:25 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
A lot of the early trucks had the transmission suspended by the 4 bolts without a cross member underneath it. My 68 GMC was like that. That got changed when I installed an overdrive and converted to an SM465 trans. The original Rear engine mount was the bell housing. Clutch gets adjusted by the clutch pedal end play in the cab. Usually about 1-1/2''to 2'' of end play

steviemack 10-17-2023 04:38 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
so just because the tranmission tail has 2 open screw holes doesn't mean the cross member is missing? I'll have to take a picture.

kwmech 10-17-2023 05:10 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Yes a pic would show a lot

72SB 10-18-2023 11:01 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
My 72 3 OTT 250 6 cyl did not have an X member. The Saginaw 3 speed did have trans mount to X member holes.

steviemack 10-18-2023 01:58 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
2 Attachment(s)
Quote:

Originally Posted by kwmech (Post 9251529)
Yes a pic would show a lot

Here are two pictures. There does not appear to be any holes on the frame that would align with a cross member.

1970 CST Short Wide 10-18-2023 11:00 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Unless your going for original, Go hydraulic and eliminate all the bracketry. I’ve done 2
My LS and my sons 383 with Muncie 4 speed. Works perfect

steviemack 10-19-2023 09:08 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Pictures of your hydraulic setup?

But I am missing the cross member correct?

67 twins 10-19-2023 09:18 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Quote:

Originally Posted by steviemack (Post 9251970)
Pictures of your hydraulic setup?

But I am missing the cross member correct?

Take a picture of the front of the transmission and the bellhousing. If there are mounts on the bellhousing then it doesn't get a cross member at the back of the transmission. It's one or the other, not both.

steviemack 10-19-2023 10:39 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
will take a few pictures.

can you explain the two bolt holes in the transmission tail that could bolt to a cross member? Looks like I have the 4 speed saginaw.

kwmech 10-19-2023 11:22 AM

Re: 1972 C10 clutch fork and clutch linkage issues
 
Normal. Same transmission was used in other applications that required the cross member. Nothing to worry about. If you didn't have the bell housing mount the entire engine would be bouncing around creating a ton of other issues

HalfBrit 10-19-2023 02:47 PM

Re: 1972 C10 clutch fork and clutch linkage issues
 
One ($) of many options
https://www.summitracing.com/parts/i...RoCIxUQAvD_BwE


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