Transmission Woes

[dwhite84]

I just purchased my 1969 K20 with an SM465 transmission and 350 small block. Intend to make her a resto-mod long term but right now I just want to keep her running and do small upgrades as I can afford them.

Today I went to move the truck and the clutch pedal went all the way to the floor. I looked under the truck and the lower fork push rod (I've seen a few names for it... but the adjustable rod to the fork) was no longer connected and the push rod swivel nut was laying on the ground. There is literally no room left to adjust the rod - which makes me think a clutch replacement may be in order (although it was shifting great the 50 or so miles I've put on it).

But now the gears are spinning in my head... and thought I'd ask the group some questions (please note money is fairly tight at the moment for me):

• If I am going to pull the transmission to replace the clutch, should I also rebuild the transfer case and transmission?
• I intend to upgrade to an NV4500 - I don't expect to ever do heavy hauling or towing - would I be better off getting an NV4500 from a junkyard and rebuilding?
• If I go the NV4500 route, what transfer case and year range should I be looking for (I understand I need one with the mechanical speed). Also, what should I expect to pay for a Junkyard find?

I appreciate any thoughts! Thank you!

[LockDoc]

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Here is my NV4500 install to replace my SM465. It would be different as far as the 4x4 but everything up front would be the same.

http://67-72chevytrucks.com/vboard/s...d.php?t=673588

I used all of the stock bell housing and clutch components.....

LockDoc

[geezer#99]

Might be better to figure out why the rod fell out.
Is the fork spring from the fork to the frame still there?
Is the zbar still in place correctly?
Is the motor mount still good? Broken mount allows the motor to twist enough to let the rod drop out.

[Ol Blue K20]

I want to see pics of the truck....

[dwhite84]

Originally Posted by geezer#99

Might be better to figure out why the rod fell out.
Is the fork spring from the fork to the frame still there?
Is the zbar still in place correctly?
Is the motor mount still good? Broken mount allows the motor to twist enough to let the rod drop out.

Everything looked correct on the linkage but I'll snap some pictures over the next few days for a second opinion. I didn't think to check the motor mounts closely but I will do that.

Is your assumption nothing is wrong with the clutch or transmission? That would certainly be a relief as it wasn't a project I wanted to tackle right now.

[geezer#99]

Yup!
Best to look it over.
Saves a lot of work and mulla sometimes.

[dwhite84]

Originally Posted by Ol Blue K20

I want to see pics of the truck....

Some pictures of the truck in this thread. Will take some pictures of the linkage: http://67-72chevytrucks.com/vboard/s...d.php?t=796924

[dwhite84]

Here are some pictures of the clutch linkage

[geezer#99]

Is that your clutch fork in the first pic?

I see you don’t have anymore adjustment on the rod.

Did you find a long spring from the fork forward to the frame?

[richard2717]

You are missing a pc in the 1st picture

[richard2717]

This should be on the end of the rod

.

[geezer#99]

I think he has that. He found it under the truck.

It appears someone used the wrong length throw out bearing and had to weld a higher mount to get the clutch to adjust. That’s the bad info as the trans needs to come out to fix the fork and maybe replace the tob.
Short term cure would be make a new clutch rod that’s longer that will help with adjustment and stay togethor until he’s ready to spend the money to fix it right.

[richard2717]

Originally Posted by geezer#99

I think he has that. He found it under the truck.

It appears someone used the wrong length throw out bearing and had to weld a higher mount to get the clutch to adjust. That’s the bad info as the trans needs to come out to fix the fork and maybe replace the tob.
Short term cure would be make a new clutch rod that’s longer that will help with adjustment and stay togethor until he’s ready to spend the money to fix it right.

Geez I missed that part . I would get a coupling nut and a short pc of threaded rod for the other end and extend the factory rod. It would require taking a lot of the adjustment back out of this end. Local hardware store should have that stuff cheap. Make sure the spring gets put back on to keep it together.

[geezer#99]

That might work if he has enough room.
Or slip a pipe nipple over the fork end to extend it. Not the best solution but doable. Pipe is easy to cut to get it close.

[dwhite84]

Originally Posted by richard2717

This should be on the end of the rod

.

I have it. Luckily it was under the truck on my driveway.

Also now that you mention it, no spring either. Not sure how I overlooked that. If I use a longer rod is that spring going to be critical?

I've done a lot of work with threaded rod and unistrut in the past so I know exactly where that stuff is at.

I appreciate all the feedback. I guess the transmission might end up being the first big project on this truck instead of replacing the front axle to get disc brakes :-)

[dwhite84]

Originally Posted by geezer#99

I think he has that. He found it under the truck.

It appears someone used the wrong length throw out bearing and had to weld a higher mount to get the clutch to adjust. That’s the bad info as the trans needs to come out to fix the fork and maybe replace the tob.
Short term cure would be make a new clutch rod that’s longer that will help with adjustment and stay togethor until he’s ready to spend the money to fix it right.

When you say "weld a higher mount" I'm not sure I'm following where you think that modification happened. I want to keep my eye out for it.

Attached is another picture of the fork.

This community is great. I really appreciate the feedback.

[richard2717]

No spring being there probably what helped it come apart. I have an extra here I can send you for shipping costs if u need one

[geezer#99]

Originally Posted by dwhite84

When you say "weld a higher mount" I'm not sure I'm following where you think that modification happened. I want to keep my eye out for it.

Attached is another picture of the fork.

This community is great. I really appreciate the feedback.

Looks like someone modded the end of the fork.
Should look more like the end on this one.

https://www.4speedconversions.com/3765372.html

Keep that link somewhere. You might need a new fork in the future.

[Ol Blue K20]

Thanks for the link to the pics. Ilike the truck.....aa lottt

[LockDoc]

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Here is a good picture of the clutch linkage spring..... I think this is on a 6 cylinder but it should be the same.

LockDoc

[dwhite84]

Originally Posted by LockDoc

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Here is a good picture of the clutch linkage spring..... I think this is on a 6 cylinder but it should be the same.

LockDoc

That is super helpful. Also, I don't have a nut between the rod and the nut to the fork. Maybe that is part of the issue as well. Thank you!

[LockDoc]

Originally Posted by dwhite84

That is super helpful. Also, I don't have a nut between the rod and the nut to the fork. Maybe that is part of the issue as well. Thank you!

No problem.

You may have overlooked it but Richard said he had a spring in post #17.

Even though it looks like it, there is no nut between the wedge and the clutch rod. That is just part of the wedge.

LockDoc