Transmission stuck in gear

[northerngmc]

I dedided to take the column out of my 69 GMC today. The truck has a 3 speed manual, column shift, aka 3 in the tree. The lever was getting very stiff to pull back to get into first or reverse.

The afternoon went well and we took the column out, pour varsol through it and watched all sorts of stuff come out, blew it out, wiped it off and sprayed it with graphite. It wants to go back and forth nicely now.

The problem came on reassemble. I went to reconnect the shifter rods and the front rod, which is connect to the back output on the transmission is stuck in the up position and the transmission seems to be stuck in gear. Not sure how it happened either but I was able to move the shifter rods up and down while I was reassembling.

So I tried crawling under and shifting by hand and I was unable to move either. I tried with the clutch in, and then had a friend rock the truck back and forth while laying under and trying to move the shifter rod.


Any suggestions?

Could it be stuck between gears or somehow if I moved both shifter rod in a way they shouldn't be able to be moved could it be stuck in two gears at once?

[JimKshortstep4x4]

It sounds like the shifter inside the transmission is stuck. If the tranny is worn it is possible that it can be in two gears. You may have to pull the cover to check it out.

Jim

[westofb]

I have seen them get stuck in two gears before...truck was not able to be driven or pushed, locked up the whole drivetrain. I would try moving both sets of linkages to get them centered....buddy had one that would get stuck like this in reverse and 2 gear. He finally sh*t canned the trans and put an auto in it!

[CSGAS]

Check the cheapest stuff first.

Make sure the linkage adjusters did not loosen. If they did, the tranny could be in 2nd or 3rd while you think you are in the gate, trying to pull 1st--and the tranny won't let you.

Make sure at the tranny that both selectors are in the center, neutral position. While you are down there, make sure all your clutch linkage is still in place--I'll get back to this at the end. Then loosen the adjusters on the column linkage, realign the linkage and retighten.

Check to make sure the mechanism that selects the plane (I call it a "tongue," I'm sure there is some misleading name for it) is actually moving between the 2-3 linkage and the 1-R linkage. Take note if the engagement tangs on the tongue are chipped at the corners from "speedshifting."

Pull the pin for the shifter arm and see if the ball at the inside end is still attached and resting in it's groove in the shift tube.

Disassemble the column from the wheel down past the shifter and see if the support washer has slipped sideways or past the dimples it rides on, to bind up the shift tube. This may be caused by the outer column shell spreading at the seam under pressure it should not see, from difficult shifting.

At each step you should clean and relubricate (I used lithium spray) anything that can handle it. If you find the bind, don't go to the next step. If the washer looks bent, straighten or replace it. The column shell can be closed up if it needs it, with a hammer, clamp or your choice of "fine adjustments" but remember that points to another problem if it is happening.

If you've gotten this far and either have not found the problem or have discovered signs of excessive force being applied during shifting, then ask yourself if you've heard any squealing while depressing the clutch pedal.

Letting adjustments go for the clutch or shifter linkage, or losing a part like the clutch rod spring (happened to mine) will wipe out the throwout bearing, pressure plate, and/or clutch. I saved it for last because this is expensive, more than seems reasonable for the cost of the parts and I don't want to cause hypochondria. Another symptom would be the clutch pedal slow to return. If your clutch is adjusted properly and the linkage taken up (the adjuster on the column base will ensure the tongue does not ever free itself from both plane mechanisms at the same time when properly set, it should always engage one at a time) you should not hear any throwout noise; minor noise that goes away at idle if you tap the clutch pedal is light wear, not a failure yet.

Most likely, one of the "disassemble, clean, relube, reassemble, and adjust" steps will cure your problem with little or no cost.

I wouldn't ever go to a floor shifter for a 3-speed after having a few 3-on-the-tree shifters. I gotta admit getting used to the first one was tricky, especially when I thought about it and tried to apply the "It's just an H-pattern sideways" advice. When I stopped thinking it became natural, and easier in tight turns than juggling a floor shifter. For short-track racing or if I had no working linkage handy, I might put a lever shifter through the floor; but the tree is as convenient as paddle shifters, to me.

[northerngmc]

Originally Posted by CSGAS

Check the cheapest stuff first.

Make sure the linkage adjusters did not loosen. If they did, the tranny could be in 2nd or 3rd while you think you are in the gate, trying to pull 1st--and the tranny won't let you.

Make sure at the tranny that both selectors are in the center, neutral position. While you are down there, make sure all your clutch linkage is still in place--I'll get back to this at the end. Then loosen the adjusters on the column linkage, realign the linkage and retighten.

Check to make sure the mechanism that selects the plane (I call it a "tongue," I'm sure there is some misleading name for it) is actually moving between the 2-3 linkage and the 1-R linkage. Take note if the engagement tangs on the tongue are chipped at the corners from "speedshifting."

Pull the pin for the shifter arm and see if the ball at the inside end is still attached and resting in it's groove in the shift tube.

Disassemble the column from the wheel down past the shifter and see if the support washer has slipped sideways or past the dimples it rides on, to bind up the shift tube. This may be caused by the outer column shell spreading at the seam under pressure it should not see, from difficult shifting.

At each step you should clean and relubricate (I used lithium spray) anything that can handle it. If you find the bind, don't go to the next step. If the washer looks bent, straighten or replace it. The column shell can be closed up if it needs it, with a hammer, clamp or your choice of "fine adjustments" but remember that points to another problem if it is happening.

If you've gotten this far and either have not found the problem or have discovered signs of excessive force being applied during shifting, then ask yourself if you've heard any squealing while depressing the clutch pedal.

Letting adjustments go for the clutch or shifter linkage, or losing a part like the clutch rod spring (happened to mine) will wipe out the throwout bearing, pressure plate, and/or clutch. I saved it for last because this is expensive, more than seems reasonable for the cost of the parts and I don't want to cause hypochondria. Another symptom would be the clutch pedal slow to return. If your clutch is adjusted properly and the linkage taken up (the adjuster on the column base will ensure the tongue does not ever free itself from both plane mechanisms at the same time when properly set, it should always engage one at a time) you should not hear any throwout noise; minor noise that goes away at idle if you tap the clutch pedal is light wear, not a failure yet.

Most likely, one of the "disassemble, clean, relube, reassemble, and adjust" steps will cure your problem with little or no cost.

I wouldn't ever go to a floor shifter for a 3-speed after having a few 3-on-the-tree shifters. I gotta admit getting used to the first one was tricky, especially when I thought about it and tried to apply the "It's just an H-pattern sideways" advice. When I stopped thinking it became natural, and easier in tight turns than juggling a floor shifter. For short-track racing or if I had no working linkage handy, I might put a lever shifter through the floor; but the tree is as convenient as paddle shifters, to me.

I think you did not fully understand my porblem.

I had the column right out of the truck, cleaned, lubed and reassembled. So your first statement about the linkage adjusters might be loose..... well I had them disconnected.

I have been under the truck and I am unable to move either of the shifter arms that come out of the side of the transmission. With the linkage disconnected.

[northerngmc]

Well I think I have it.

I totally disconnected the shifter rods at the column and went back under the truck. It still seemed stuck. My 9 year old son was hanging out and got bored about this time and went around the back of the truck and tried pushing it forward in an attempt to get out of the garage. Needless to say he got an earful for pushing on a vehicle while someone was under it. BUT then everything was free and moving again.

All that is left is to have lunch and take it for a test drive.