The Stovebolt Site Forums The Parking Lot Big Bolts Broken shifter fork

Well, I got a problem. As you may know, the truck is a 1946 1-1/2 ton 216, transmission is a standard 4-speed forward one reverse with the reverse lockout lever and rod.

I broke a shifter fork in the gearbox the other day. Shifted from reverse into (what I thought) was second gear, but turned out to be granny low, and the transmission would not shift out of granny to anything else. Hmmmmm, the shifter lever in the cab seems to work fine but she's stuck in granny low, and placing the shifter lever in third or fourth position results in total transmission lockup.

Took out the floorboard, removed top off transmission, and low and behold the shifter fork on the center shaft is broke off.

Now I've never worked on a transmission before, so I'm looking for expert advise from transmission gurus.

Here's the questions:

Should I go for replacing the shifter fork, or replace the whole transmission?

If I replace the shifter fork, how do I insure that I get all three of the shifter forks in the right place in relation to the gears on the shafts when I put the buzzard back together?

Just looking at the gears and all, I don't see any wear or rounding of the teeth -- heck, the truck only has a little over 70 thousand miles on the tranny and driveline -- I would say it is barely broke in.

I would appreciate your input. This will also appear in the Transmission and Driveline corner of the garage.

In the (much newer) NV4500, you just kind of push the forks and sliders around when setting the top cover back down. It won't go together unless everything is lined up. A shop manual for your year probably has teardown/reassembly proceedures.

put in a new fork, no big deal just get the spring on the rails and detent balls in right place...and put everything in nuetral. all the gears will be in the middle. and all the forks in neutral...and put it back on... worst that can happen is like now ya got it in two gears at once and thats what locks it up..... if so just recheck for neutral on everything... its not that hard....

replied on other thread. wouldn't transplanting top plate and forks from another like transmission work? next question why did the fork break is there something else jamming in the transmission?

Good question, kb3csw.

Before reassembly, I'm going to get the mechanical stuff checked out, but I don't believe there is a problem beyond the broken fork.

As tough as these old trucks are, I think I did it. I know I can stand a little adjustment in the clutch linkage. When I mash the clutch pedal to the floor, it requires getting the pedal ALL THE WAY to the floor to get the clutch to disengage, and I got lazy.

Had any luck getting your repair done?

Oh,yeah! Been drivin' the truck and with the forks all right and the clutch adjusted just so Ol' Blue is shiftin' like a new truck!

A friend and I (not Mando this time) took the top off the transmission (that was easy), unscrewed the keeper bar off the fork rods, pulled the forks off the rods very carefully, paying particular attention to how everything came apart, and removed the remainder of the broken fork, saving the other two.

Care must be noted when removing everything because the detent springs and balls in the forks tend to spill out and go bouncing all over the place.

Reassembly is just the reverse of taking it all apart--right? Well, sorta. Unless you want to lay on yer back and reassemble the gear changing device, yew gotta pay partiklar attention to how to get the d%#@&cg balls and springs back in their little caves interr them forks while yew putt the rods back threw the forks and be sure to rotate the rods away from the detent balls when yer pushin' the rod back threw the fork so the whole thang don't go bowin' up on ya. Got it?

Next we re-assembled the whole shebang then realized we fergot the do it right (since the d&#@*@g thang is upside down!), so we disassembled it all agin, fixed it right and reassembled the booger once more.

It was easier to get the forks back in position on the gear drivers than I thought. Did a little adjustment on the clutch (now that's somethin' I sorta understand), and I was READY.

Some grease, I set down in the seat, a little run threw the gears jist to see if everything appeared to work before puttin' the floorboard back in, and got ready for the big moment. I worked up a little pucker here and there, kicked the gears into neutral, turned the key, put the clutch to the floor, mashed down on the starter and cranked 'er up--nice and smooth in neutral.

Ok, just to prove that everything was ok, I shut 'er down, shifted into second, and cranked 'er up again--nice and smooth.

Now time to run through the gears with the engine running. Nice and smooth. So I got brave and while in second, let the clutch out.

Off she went with me steerin' away, shiftin' gears jist like she was a new truck, and I haven't stopped yet.

If you see me goin' down the road, give me a big ol' "Howdy" wave and I'll pull over and give you a ride.

Heck, I'll even let you drive 'er!

thanks for the update and congradulations