d7e,powershift transmission

Scott, if the trans oil is not over full now, throw in another 5 gallons.
The pump pickup may be drawing air as you make a shift and try to back up hill.
If that doesn't work look for a suction line leak.
Later Bob

thx Bob,will check it over tommorow,Scott

Scott. You've got me curious now. Did you have your nose up at more than a 45 degree angle when you were climbing out of that hole and did it take you more than 30 seconds at that angle to get out. If this is the case, your trans oil traveled back to the bevel gear compartment and like Bob said you broke suction. Not a big deal if you're in a hole but a real big deal if you're on the side of a hill or mountain and its a long ways to the bottom. You won't believe how fast you'll get to the bottom, backwards, trying to shove the brake pedals through the firewall before suction returns and the tracks lock up. Now that folks on this BB are buying and rebuilding the old powershifts, its something to keep in mind if they don't have an old operator to teach them about hazards that were common knowledge 40 years ago.

If you get in this situation and you're not sure what to do, back up the slope.

Good point.
Both the transmission pump and steering clutch control/brake pump suction come off the front of the transmission case.

Correction:
On digging a little deeper, yes the connections are at the front of the case but both have suction pipes (with strainers in them) that pass through the transmission to take suction from the bevel gear case sump. With that arrangement it would seem worse to back up a grade or be going downhill than going forward up hill.

yes it was at a 45%, but it will do it pushing and backing up, iv had them do it on 8h were it would do this every once in awhile, but only pushing, not backing up,tranny is up to the full mark, would another 5 gallons help? thx Scott

yes it was at a 45%, but it will do it pushing and backing up, iv had them do it on 8h were it would do this every once in awhile, but only pushing, not backing up,tranny is up to the full mark, would another 5 gallons help? thx Scott

If your nose is up and your oil is in the bevel gear compartment, an extra 5 gallons will raise the oil level enough to keep it from breaking suction "most" of the time. It sounds like you have a different problem if it does the same thing in reverse. Time to follow Bob's advice and start looking for places you could be sucking air. If you start working in the hills, use Bob's trick and overfill your transmission 5 gallons to add a margin of safety. You'd be surprised how fast a rock can move your nose closer to vertical when you're already maxed out on a slope which triggers a natural tendency to slow down and gives her time to break suction.

I'm told Peterson Caterpillar used a hose to extend the suction line back towards the bevel gear compartment to eliminate this problem but I've never seen any of their handiwork first hand. Hint. Hint. Maybe someone has some info or first hand experience with this solution.

Got interrupted in the middle of typing this post. Sounds like OM is getting you going.

serial number is 6841, will try the extra oil first,thx guys, will post the results in a few days when i work it again, thx Scott

That late a s/n uses the single hydraulic pump for trans and steering clutch control.

Pressure check is 300 - 330 psi with engine at high idle and trans in neutral.

Test port is the plug on top of the pump.