Ring and Pinion on 8640

[newgenjdcollector]

Bought a decent 8640 with a ring and pinion issue. My original idea instead of tearing into it was to swap out the rear end completely. I acquired a second rear end for the job, but after seeing it upon arrival, I am less optimistic. Both axle seals are leaking and I cannot shift the ABCD range by hand. Seems odd to me. The rear end on the tractor now doesn't have any leaks and I can shift the gears easily. Now I'm wondering if I should just put good parts into it instead of using the donor one. I just don't know what's involved with changing a ring and pinion. Anybody have a general procedure of what's involved?

Right now I have the wheels and fenders off and the fluids are drained. When I pulled the screen it was about 30% covered with shavings. In the bottom of the case I found a small diameter pin, maybe 2 or so inches long. Any idea on what that is?

 

[tim s]

When axle seals are leaking it's almost always because outer wheel bearings are bad and the axle has been moving in and out a bit, which takes out the inner seal,,the range lever not moving could be because things are in a bit of a bind,,I would need a pic of the pin to get a better idea of what that was. The bottom shaft repair is a bit ornery but on the larger transmission you have a little more room to work,, I could walk you through it when your ready to do it....

 

[newgenjdcollector]

Ok I'll get a pic of that pin for you.

 

[4520BW]

At least it's an articulate tracor so you
don't have s cab in the way! I had to put
a D range synchronizer in my 8430.
(Dad like to.shift on the fly)

 

[newgenjdcollector]

So here are some pics. First one is the pin I found in the bottom of the case. I did get the trans cover off but haven't pulled the rockshaft yet. Just need the best way to get at the ring and pinion. Holding off on splitting it till I know what's involved with the ring and pinion.

 

[tim s]

That is a rear pinion roller out of the bearing..

 

[newgenjdcollector]

Tim, I did manage to get the trans cover off and prying around on the gears. The large gear in the center toward the rear of the trans doesn't seem to be meshing with other gears. It free spins or just lightly grinds against a smaller gear on the LH side. Wondering if a bearing failed and let that gear drop out of mesh. But really I don't know.