642 drive motor removal

[langoley]

Ok,I have a problem. I lost power/drive on the left side of my 642.I was just pushing some lumber debris when I heared a "pop" and lost all pull on the left side. I have another machine for parts but it is a later serial # machine with the spline motors.The motor came out of the late model machine easily after removing the outer bolts. Now for the prroblem,how do I get the earlier style motors out? I removed the mounting nuts but the pump is still attached to the gear set.After pulling the top covers I see that both sides have a "nut"on the inside of each shaft that is approx.1 3/4",and once I get it out do I have to replace the entire center "gear set" with the motor?

 

[Tazza]

I remember hearing that some were bolted through like the one you are having issues with. I think you may need to change the gearbox too if the motor is indeed the problem. You will then have the newer style setup. While in there, you may want to do both sides, then the same drive motors will be used so it should travel at the same speed.
I assume they are two different style drive motors? if they are the same, you could find the broken part and possibly swap them over to create minimal work for you?
As you have noticed, the newer style has a gear that looks like a dog bone, this allows it to wobble inside the housing. It also makes for easy removal, 4 bolts and slide it out.

 

[langoley]

I remember hearing that some were bolted through like the one you are having issues with. I think you may need to change the gearbox too if the motor is indeed the problem. You will then have the newer style setup. While in there, you may want to do both sides, then the same drive motors will be used so it should travel at the same speed.
I assume they are two different style drive motors? if they are the same, you could find the broken part and possibly swap them over to create minimal work for you?
As you have noticed, the newer style has a gear that looks like a dog bone, this allows it to wobble inside the housing. It also makes for easy removal, 4 bolts and slide it out.

This 642 doesn't have a "gear box" like a 743. The motor just bolts directly to the chaincsase.And yes on the older one it has bolts that go through but the newer one has studs and external nuts. As close as I can figure the old one is a taper shaft with the nut on the end.

 

[SkidRoe]

This 642 doesn't have a "gear box" like a 743. The motor just bolts directly to the chaincsase.And yes on the older one it has bolts that go through but the newer one has studs and external nuts. As close as I can figure the old one is a taper shaft with the nut on the end.

Are the motors identical other than the output shaft? If so, "Frankenstien" is an option... assuming the shaft in your bad motor is still salvageable.

 

[langoley]

Are the motors identical other than the output shaft? If so, "Frankenstien" is an option... assuming the shaft in your bad motor is still salvageable.

I got the motor off by taking the front axle gear off,but i never did get the gear off the motor.I think I am just going to replace both motors and center drive gears(sprockets) as I know they are good from the newer machine.

 

[Cyclone Ranger]

I got the motor off by taking the front axle gear off,but i never did get the gear off the motor.I think I am just going to replace both motors and center drive gears(sprockets) as I know they are good from the newer machine.

I recently pulled the sprokets off of my tapered shaft motors using a large 3 jaw puller and a torch. When the first sprocket broke loose it jumped 6 ft in the air. There was no chance of getting these sprockets off in the chain case. To get the motors out I broke the rear chains and used master links to put them back in. It's not hard to see why they went to a splined shaft design.