Engine removal on 642

[tmq]

Thinking I might have to remove my engine to replace the head gasket. Has been using some coolant and can't find a leak. Thinking it might be the gasket. After I unhook everything does the ujoint simply slip back off the spline of the pump. And when reinstalling are the spline and ujoint simple to get lined up? Do they just slip back together like a tractor pto shaft.

 

[OldMachinist]

It should just slide off the shaft in theory but depending on how long it been since the last time the engine was out it may not slide easy. Getting it back on requires two people normally, one to reach in from the front end and another to push the engine in. Inspect the u-joint while you have it out and replace if there's any doubt about it's condition.

 

[Tazza]

It should just slide off the shaft in theory but depending on how long it been since the last time the engine was out it may not slide easy. Getting it back on requires two people normally, one to reach in from the front end and another to push the engine in. Inspect the u-joint while you have it out and replace if there's any doubt about it's condition.

Excellent advise. If the U-joints feel sloppy at all, they need to be replaced.
I have actually removed a head on a 743 without removing it. I did need to remove the covers for the oil cooler and the exhaust hose, you may be able to get by doing the same?
Removal of the engine isn't hard at all. Re-installing is pretty easy. Slip it mostly in place, get a helper to bar the engine forward SLOWLY. You need to lay on the pump with your hand through the blower housing and hold the coupling up. Get your helper to bump it slowly and keep your fingers from between the pump shaft and the coupler! If it doesn't quite line up, it will start though, get your helper to rotate the engine crank a little, it will then slide into place with ease. A little grease on the shaft will do wonders if you need to remove it again later.

 

[spring]

Excellent advise. If the U-joints feel sloppy at all, they need to be replaced.
I have actually removed a head on a 743 without removing it. I did need to remove the covers for the oil cooler and the exhaust hose, you may be able to get by doing the same?
Removal of the engine isn't hard at all. Re-installing is pretty easy. Slip it mostly in place, get a helper to bar the engine forward SLOWLY. You need to lay on the pump with your hand through the blower housing and hold the coupling up. Get your helper to bump it slowly and keep your fingers from between the pump shaft and the coupler! If it doesn't quite line up, it will start though, get your helper to rotate the engine crank a little, it will then slide into place with ease. A little grease on the shaft will do wonders if you need to remove it again later.

I have a 742, similar to yours and just did a head gasket 2 months ago. You don't need to remove the engine but you do need to take the intake, exhaust manifold, governor belt, governor bracket, thermostat housing and hoses off. It takes about 4 to 5 hours to do total. Make sure you change teh thermostat, and oil upon assembly.