SOS Questions and Adjustment?

Hi. Trying to tune up my 1959 871. Making some progress with some good help here on this site and of course, reading the manual. But I have a couple questions:

1. As this tractor has been driven over the years, what causes the transmission bands to require adjustment? Do they tighten up over time? and this is what causes some selector speeds to lug? (such as R1..as I am experiencing). ?

2. I cant pick up from the manual a couple details:

2a. When it says to get the tractor up to operating temperature to adjust the bands? Does that mean leave the tractor running while making band adjustments?

2b. Uncoupling lever: I was able to move the uncoupling lever counter clockwise just a bit. But, when I started the tractor and put the tractor into 3rd speed, it wanted to drive forward. (I was in the process of adjusting Band 1 at the time.) I thought that if that lever was moved and unlocked, that the tractor would not be able to move forward while shifting into gear.

Advice and onions needed. Thank you in advance.
 
1. Bands have friction material on them that wear over time. If anything, they loosen up. The lugging you feel is normal in reverse, it's just the tranny fighting against itself because most of the clutch packs have some drag and want to go forward.

2a. Read the manual carefully on the band adjustment. On the later SOS trannies, some of the bands are adjusted with the engine off, and some with the engine running (I forget the exact details).

2b. You're lucky you didn't get run over. Make certain that the lever is fully in the disengaged position. The service manual should show what that looks like.
 
If the lever is in the fully disengaged position, there should be no safety concerns with putting the tranny in gear while standing next to the machine. I've done it many times myself.
 
(quoted from post at 07:35:56 05/20/19)
Uncoupling lever: I was able to move the uncoupling lever counter clockwise just a bit. But, when I started the tractor and put the tractor into 3rd speed, it wanted to drive forward. I thought that if that lever was moved and unlocked, that the tractor would not be able to move forward while shifting into gear.

It takes about half a turn to uncouple the disconnect.
Your sliding a splined collar off the end of a splined shaft, it takes a bit of effort to disconnect them sometimes.
Rocking the tractor back and forth helps.
Until you can freely roll the tractor back and forth the disconnect is still engaged.
If you can't move the tractor jack the left back tire off of the ground and rock it back and forth while rotating the disconnect.
 
The little leaver used to hold the splined coupler in mesh with the splined shaft is made so the opposite end, when installed with it on the rotating shaft locks it in the disconnected position. So place it in position and tighten the nut to prevent it from meshing back together.
Jim
 

There is a lot of drag on the clutch packs with the oil cold. Running the engine will not heat the transmission oil. You need to drive it for fifteen minutes or so if starting above 50 degrees, while shifting through a few of the gears.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top