Craftsman Gear Shift Stuck After Stopping

[TiIngot]

Craftsman Tractor Model - 917.252510 - 42" Deck - 16HP Briggs
Transmission Dana Transaxle Model - 4360.79

This thing is about 30 years old. The engine was blown when I received it (no oil), and previous owner has no history to help. It came with the house. Just completed an engine swap with a 15.5HP Briggs, used the original motor dual belt pully and did a brake repair. Also used the drive belt that came with the mower. It remained installed and was only removed from the engine pully during the swap.

Now the first test drive. The gear shift moves easily when not running. The gear shift moves easily after starting the engine throughout its entire gear range with the clutch in.

Release the clutch/brake and it drives. Push brake and it stops. There is no sound or smell indicating the drive belt is under heavy tension when stopped. But the gearshift is frozen in whatever gear it was driving in, forward or reverse. The only way to shift gears or put it in neutral is to stop the engine. Then the gear shift can be moved.

At this point I cannot find a mechanical reason for the gear shift to lock up after the tractor moves in any gear. The clutch releases the belt tension, and the tractor stops and the drive belt stops moving, but the gearshift remains locked until the engine is shut off.

My first inclination is somehow, even though the belt is not moving there is tension on it that somehow locks the gear train in the transaxle until the engine is shut off.

Looking for suggestions please.

Lee

Ps: This is a winter hobby. In three years, I have rehabilitated nine tractors and sold none. They are given away to others. This one is earmarked for the neighborhood swim club if I can make it safe to use.

 

[StarTech]

Make sure the pulley v groove is not damaged. Even a slight bent place can cause belt drag.

 

[grumpyunk]

When you apply the brake and lock it in position, you are putting a load on the geartrain through to the drive axle and wheels. The brake disk just locks a shaft linked to the output shaft and thus the drive axle/wheels. I think with no basis that there is some wear internally that is causing a bit of binding on the gear selection shaft. The selector shaft rotates and moves forks back and forth to connect input to output via dog clutches. The forks wear over time as do the 'keys' used to lock the gear to the shaft. I have the same thing, but find that allowing a bit of clutch, just a bit, will make the gearshift move again. Taking the transmission apart, cleaning, and replacing the grease may alleviate the situation.
The grease used has Bentonite mixed in as a solidifying agent as the lubricant only has to deal with slow turning parts and needs it to stick to the gears. I think.

 

[ILENGINE]

If the drive belt is not disengaging fully when the brake is depressed will cause the exact issue that you are talking about . Can shift freely without the engine running but will not shift with the engine running.

 

[TiIngot]

Thank you to those that replied. Things are very hectic this time of year and I’m taking a break from the garage for now. I don’t know why but the brake was shimmed with washers on the adjustment nut and not working at all when I got it. The first thing I’m planning on doing is disengage the brake and see if that does anything.

I will update this thread when I get back at it.

 

[TiIngot]

OK I lied!! It warmed up a little today, so I made it out to the garage. I released the center brake adjustment nut and the mower shifted OK. I tightened the nut some and it still shifted OK but had no brakes. Kept tightening the nut to the point where I have a very little brake pressure and can get the shift lever to move with a little giggling/pressure combined with letting the clutch in and out some but the brake is not very good.

Is there something I am missing? What about the rod adjustment on the spring? I have heard when the parking brake is set the spring should be compressed to 1.5 inches. If it is a little more or less that 1.5" how will that affect the shift lever movement vs brake action, if at all?

The way things are now, I have a little brake action. But if I was on a downhill grass slope, I am not sure if I have enough.