MTFCA Forum

a couple years ago I asked if anyone had been in the situation of only being able to go in reverse, no forward low or high. no one ever had that problem. I didn't want to tear the engine apart, so it sat on the back burner for a bit. I wondered if the pinion gear could be spinning loose going forward and tightening up in reverse, I took the rear end out today, BINGO. my theory was correct. the nut had spun off and the pinion gear was loose.
I am ordering a new drive shaft tomorrow.

maybe this will help someone in the future!

Rick Nelson

Not so fast Rickey. First, the drive shaft, in forward mode spins in a direction that would cause a tightening, not loosening of the nut.
Secondly there is a woodruff key & taper that holds the pinion gear in place. When the nut runs loose, the key gets sheared.
I can believe there is enough burr to partially hold in the low demands & lower gearing of reverse as opposed to forward demands.
Anyway thats what my reasoning tells me. I could be wrong.

I too can see no reason for the car to drive in reverse and not forward. If the gears are in mesh to drive backwards, they are in mesh to do the same forwards. Your search may not yet be over.

Allan from down under.

Jack the car up on both rear wheels in neutral and press your reverse pedal and see if the wheels turn in reverse. If you have the linkage adjusted correctly you should get a good neutral. After you check if your wheels are turning in reverse put the car in neutral then use the low speed pedal and see if the wheels turn froward and then go into high gear.

Allan wrote: ↑

Sun May 18, 2025 7:37 pm

I too can see no reason for the car to drive in reverse and not forward. If the gears are in mesh to drive backwards, they are in mesh to do the same forwards. Your search may not yet be over.

Allan from down under.

Allan, Is it possible that the woodruff key sheared/messed up do to the pinion nut coming loose. Thus allowing the driveshaft to spin in the pinion gear in forward motion, but having enough of a burr to let it catch in the gear while in reverse. Years ago I had a very similar thing happen with an outboard motor lower unit on a boat I had. Just a thought...

Since the rear is already out, start it up and run the gears watching the output shaft. Piece of mind.

Remember to bolt up the ball cap first.

the key was out and in the bottom of the housing, and the spool bearing fell apart, the ring and pinion gears are chewed up a bit. i am not changing my diagnosis yet. I will keep you posted.

Rick Nelsom

Let's give Rick the benefit of the doubt here. After all, he has the actual parts in front of him and all we have are guesses.

If he does not wish to take advantage of the rear being pulled to check out the ball cap and such while he is at it, so be it.

Please point out where I disputed his diagnosis.

Maybe you want to install another front end and ditch that rear axle.

i think that is what the guy did here.

big2bird wrote: ↑

Mon May 19, 2025 12:27 pm

If he does not wish to take advantage of the rear being pulled to check out the ball cap and such while he is at it, so be it.

Please point out where I disputed his diagnosis.

Please point out where I referred directly to you...

On the first T I got, I was driving along and all of a sudden went into neutral. Couldn't go forward or backward. I was able to push into a parking lot and called someone to bring a truck and trailer and pulled the car home. I found that the drive shaft had broken about 6 inches in front of the rear axle. Someone had removed an in line transmission and welded the front end of one drive shaft to the rear end of another. The weld was just around the outside. Not even welded in the center of the shaft. I was able to replace the drive shaft and fix it. The short end with the threads makes a good knock off puller for the rear wheels. Just back to nut out far enough to fit the thread on the drive shaft and jack up the opposite wheel. Then strike the end of the shaft with a heavy hammer.
Norm

I guess it's back to the future.

Since you have already found the problem, this will not apply in your case. But in case someone else might have a similar problem, I can think of something which could cause this problem. If the parking brake rods are too long, the brake handle will pull the rods forward till the clevis hits the hogs head. . This will prevent the clutch engagement to high gear. And if the low bands are also worn out or the low cam and notch are worn out, you will not be able to go into low.
Norm

thanks, everyone. in my defense I have been driving this car since 2010, I bought the rear end and driveshaft form someone who was supposed to be a professional restorer, he said everything was good. when it broke down, and got it home, of Corse I did the normal trouble shooting. I removed the inspection cover and found nothing strange that you could see. And when no one had an answer, I thought of the only parts I did not restore was the rear end. I am not saying I found the answer, but in this case, it seems like the best place to start. Ya know you wouldn't tear an engine down just to find out it was out of gas.


Rick Nelson