The Stovebolt Site Forums The Shop Area Engine Shop Help!!! Tranny Jamming

New to the board here... I think I checked all the previous posts but haven't found an answer to my problem. For the sake of introduction, I have a 1954 Chevy 1/2T 3100 P/U, 235 engine, And it has given me 7 years of good daily service (the first two years were pure hell!!!). "She" and I are celebrating our 9th anniversary today. Yay. Now the problem: Most recently I drove it from Phoenix to Los Angeles and this is when the trouble began.

Leaked a lot of oil between Phx and LA (you can probably follow the oil slick I left behind me), and once I got to LA I noticed that 1st gear was starting to act differently. When releasing the clutch in 1st there's a lot of clutch chatter/rattle that causes the whole truck to vibrate. Also, the gear shifter has begun to jam up when shifting between 1st and 2nd. I have gone in and readjusted the transmission linkage to specs and it is still jamming up. I also took some of the extra play out of the linkage with the addition of washers and still no reduction in the jamming up. Adjusted the clitch pedal free travel as well.

I have noticed that when the problem occurs, it is because the shifter gate in the gear box is not lined up properly, and this appears to be because the detent in 1st gear seems a little weak. The shifter either does not pull the gate fully into the neutral position or it slips out. Not sure which.

Also, could my choice in grease have anything to do with it? I've been using the same type of grease in the gear box for years (a black molybdenum grease I think), replacing it as it gets forced out (any way of sealing that up too?)

I should also add that the week before I went on this journey the large pin/bolt that holds the ilnkage together fell out and the gears dropped (thankfully into third and I was able to drive carefully to my destination). I doubt that had any major effect on all this. But I thought I'd mention it anyway.

The gears have occasionally jammed up in the past, but now it's happening every time I am behind the wheel, sometimes several times during one trip. And this is LA... not a great place to be having this kind of trouble so frequently. Sorry for the long question... just wanted to give as much info as possible. Anyone have any ideas I can try?

I know this sounds stupid, and I'm sorry if it does. But I didn't see it in the body of your message.

Is the oil level in the transmission back to normal? When you pull out the plug on the side, the level should be to the bottom of the hole.

Okay, next question, what did you use to refill it with? I was advised to use 90 weight gear oil.

Finally, I find that using a tube of BG gear lube is some of the best medicine for an old transmission. Try it, the stuff is fantastic.

The transmission case is plenty full... in fact it's the only part that seems to be retaining its oil. Using 85 or 90 weight ln there.

I don't think I have ever heard of BG Gear Lube, but I'll check it out. Every type of grease I've used in the gear box has gotten squished out the lower end by the gearshifting action, but the black stuff has proven to be less prone to excessive leakage. Will the BG stuff stay in there?

OK... back to this problem.

This may be long, as I want to explain the problem in detail...

I got a gear shifter box (what GM called the lower control shaft and housing assembly) from another stovebolter which he took out of his '54 Chevy truck, so I could replace the one in my '54 truck as it had been leaking excessive amounts of grease where the end of the lower shaft protrudes through the housing. I compared the two parts and found they are the same size. So I took the "new" one, cleaned it up, and went to install it.

With everything put where it should be, I'm not getting sufficient clearance at the gearshift lever to shift gears.

Here's how it looks: Starting just under the steering wheel, the gearshift lever bracket is mounted in the holes provided in the steering column (no wiggle room there) and the clearance between the lever and the bracket is as called for in the specs.

Moving on down, the upper and lower control shafts are attached with the clamp by a pair of bolts that run through the bolt holes and the concave grooves in the shafts. Not much wiggle room there.

On the other side of the firewall, the gearshift assembly housing is mounted to the steering column with the little protrusion (I'll call it a "button") in the bottom sitting in the long hole in the column as it should be. It is resting at the lower end of that hole. It could slide up the steering column about an inch, but even at the bottom, with everything above it to spec, the gearshift lever is positioned too close to the steering wheel. Adjusting the box higher on the column would only push the lever closer to the wheel.

In this setup, there isn't enough play in the gearshift lever to allow me to pull the tab up into the 1st/Rev gate in the gearshift box.

There is a small round hole in the column an inch or so below the long hole. If I move the gearshift box so the button sits in that secondary hole, the upper and lower shaft bracket cannot be bolted properly, and the 1st/Rev outer lever that connects the gate to the 1st/Rev transmission rod doesn't clear the manifold. (Admittedly, the "new" box came with a slightly longer 1st/Rev outer lever, and I may have to use the old one as a last resort.) Plus, a section of the oblong hole is exposed and could allow dirt and unwanted crud to get inside the steering column.

This means that as of now I have to find an arbitrary place on the steering column to mount the box, and as there is no hole for the button to drop into, there is no up/down or side/side stability. This was part of the problem I was having with the old box too.

Short of the steering column having shrunk in length over the years, this just isn't making any sense. Separately, all the pieces fit as they should, but together the control shaft is just too long.

So I guess one of the things I am wondering is if GM made the lower shaft assembly in two different lengths for these trucks.

Has anyone else run into this problem? If so, how did you solve it? I don't want to continue with the gearshift control box attached to the column in this manner because it gets out of alignment and causes all sorts of shifting problems.

HELP!!!

I guess it's also worth asking whether GM made their steering colums different between the models or even between the years... ie: is the '54 steering column different than the '53 or the '56? I had a mechanic who replaced the steering column for me years ago. Could he have used the wrong one and that's what's causing this problem with things fitting properly?

The steering column is incorporated into the steering gear box, so if the "column" was changed, it was an assembly that was changed.
The AD (47-55/1st) steering box is not the same as the TF 55/2nd-56. The 57-59 is 4" shorter than the 55-56. It could be that you have a unit from a 4 speed truck that was not set up for a column shift.
You could also have a mixture of shifter parts that are not compatable. Try to look at one that works correctly and see if you can see any differences.
Fred

From the sounds of your first post it appears that you have an oil soaked clutch. This can and will cause most of your complaints, especially when the oil gets baked after driving it continually that way. That's where I would start looking,
Scott

Hi Fred,

Yep, the whole steering gear box and column was replaced. I don't recall at the time that it was a different size, but then I can't be 100% sure. However I didn't notice that the steering wheel was any closer or further from the dash. I think I would have clued into that at the time it was done.

Also, the unit that is in there was set up for a column shifter as it had the threaded bolt holes for the gearshift lever retainer. And it has the oblong hole for the shifter mechanism. It just seems that either the hole is further up the column than it should be or that the lower shaft is longer than it should be. One of the two must be true or the thing would fit as it was intended.

With the steering column/assembly info you provided I am inclined to believe that it is not that the steering column is too short, but rather the lower gear shaft is too long... perhaps designed for a larger truck (like a 1-ton?)

Has anyone seen any differences in these parts that might account for the improper fit?

From the sounds of it your original shifter box is worn out and the replacement one is incorrect.
Send me an email.
Fred

mandrew,

The 3-speed shifter mechanism changed in 1954. The rods mounted on the steering are different lengths and I think that most, if not all, linkage rods are different lengths (from earlier years).

Tim

Also, check your front and rear motor mounts. It's possible the engine has moved.

Moved??? And left no forwarding address? ;-)

If your engine and trans moves while you are taking off, and your shifter levers aren't, it will cause all kinds of problems.
Scott