Shifting issue on my 1972 C700
 

Hi all, i just bought a '72 C700. its pretty cool to me since it has a fabco 4x4 conversion. I'm currently trying to figure out why I can't find reverse. It seems to go into all the forward gears fine, but i can't find reverse. I'm thinking the linkage could be the problem. Right now its stuck in mud. So, i'd like to move it a few feet onto a hard surface. Is there a way for me to disconnect the linkage and manually shift the transmission into reverse? It is my understanding it has the clark 5 speed transmission. The black shifter knob shows reverse lower left, 1st upper right. I can't get the shifter to move to left any more. So its possible i'm only getting to 2nd and 3rd. Any help on this is appreciated! gary

Remove the shift lever from the top of the transmission. Look in the hole to see if all the shift rails a lined up in neutral. If not make if so and put the stick back in.

On some clarks reverse is far right and up, and second/third is as far left as they go. The fact that you would never expect that suggests that the transmission may be fine. That is something to hope for anyway. If you've had it in low gear then maybe that's not it. You could at least try lower right.

if there is any kind of reverse lockout, that would produce the same problem. I never saw one that way.

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I don't think i can get access to the top of the transmission. This is a dump truck - but the hydraulics for the dump are missing - so I can't move the flatbed. Is there another way to access it?

I think maybe you are right about the shift pattern. Its frustrating since the shifter knob shows reverse bottom left. I usually rely on the knobs. So, for a '72 Clark is there a certain shift pattern I can assume? I tried most locations to left and right and everything seems to go forward at different efforts.

I had a tow truck pull it out of the mud. so for now I'm not in a hurry, but I definately want to get this cool truck road ready.

i noticed the image says before a certain vin number. my vin is C70EVN33292. So is that image still the right one for my application?

It is now...

I don't know. I looked under the cab at what I thought the shifter - it looked like a couple of u-joints. I don't see u-joints in that photo. I appreciate all the help.

I believe you're looking at the steering shaft, as it contains two u-joints.

See 3815 in pic:

I think you are right. I was looking at the steering joint. Once the rain stops here i'll go out and look at the correct linkage. thanks!

I gave it another try to shift it. This time I put some tape on the dashboard and on the bench seat, and each time I was able to put it into a gear I marked either the dashboard or the seat. Based on this, I was able to get into (4) gears only. I'm assuming I found 2, 3, 4 and 5. I tried slamming it to the left a few times and then up, and when I let out the clutch it made a grinding sound. The previous owner did mention to me (and showed me) that the flex hose for the clutch slave cylinder was leaking. I did visually see the leak. Is it possible that if there is air in the line or not enough hydraulic fluid that I could not be able to shift into 1 and R ?

On a side note, i checked the Letter L shown on the data plate for transmission. According to the demo pdf for '72 ford trucks L stands for an Allison AT540. And, one of the large factory stickers on the dashboard says AT540 - and it gives an explanation for each shifted gear. But, since I know the vehicle has a clutch, and a manual shifter I can only assume that when FABCO did the 4x4 conversion they must have swapped in the Clark 5 speed. Does that make sense?

The clutch does not affect whether or not you can go into gates to the left and right, not at all. If the clutch was not releasing, it would have been noisy before you let the clutch out.

The shift linkage on a C series Ford was the worse thing about the whole truck. A Rube Goldberg contraption that needs to be adjusted and lubricated often. These trucks were MUCH better with Allison automatics. That having been said, if I were you I would get a service manual and follow the adjustment procedure. Lube everything, check carefully for loose and worn parts. And yes, the shift linkage has 2 u-joints in it! (7A134 and 7B170)

Seriously, Ford should have copied the shift linkage on the Chevy tilt-cabs. Much better setup.