1985 John Deere 640

[jimmyyaple]

Hey, guys I got a 1985 John Deere 640 with power shift transmission. I just bought it. When the fluid is cold it shifts fine. When fluid warms up gears 1-4 slip under pressure 5-8 is fine all reverses are fine. The guy I bought it off of just had trans rebuilt. Any ideas where to start? Thank you.

 

[jimmyyaple]

This is receipt from trans

 

[Diesel Dave]

Hey, guys I got a 1985 John Deere 640 with power shift transmission. I just bought it. When the fluid is cold it shifts fine. When fluid warms up gears 1-4 slip under pressure 5-8 is fine all reverses are fine. The guy I bought it off of just had trans rebuilt. Any ideas where to start? Thank you.

Repair invoice is from Feb 2022 .
I think a full transmission pressure test would be the place to start.
If you’re thinking of tackling this job yourself I would recommend getting service manual TM1124 .

 

[jimmyyaple]

Ok I will get one, did you by chance look at the invoice I attached to this thread?

 

[Diesel Dave]

Ok I will get one, did you by chance look at the invoice I attached to this thread?

I did

 

[Diesel Dave]

Not a whole whack of transmission hard parts.
-Pump,
-13 clutch disks
- clutch/brake housing
-1 pinion

 

[Steve Austin]

Every skidder i worked on that had that fine metal from the return circuit from differentials where it returns to the transmission case had the clutch oil manifold worn out.
I do not see it on parts list (AR90848).
Some supported models had returns screens where return lines entered the transmission case.
I suspect yours Skidder does not have these screens.
The filter was bypassed because it was clogging up constantly unfortunately this contaminates the whole hydraulic system.

 

[Steve Austin]

Just a word of caution i see where it was noted that front diff was dry and rear diff had fine metal.
The metal is most likely from the brake pads being worn out and now metal to metal. I f the problem with the source of metal is not corrected on both differentials this will continue to contaminate the whole system hydraulics and transmission.