Auto Trans fails on steep climb

Has anyone else experienced this before and if so, how did you remedy it?

My 1990 Xj with an auto trans has now on a few occasions suffered a power loss on a very steep climb.

Twice in Moab on a steep climb all of a sudden forward motion stopped while the engine maintained it's rpm. I backed down using gravity, power returned and I tried again only to arrive at the same problem. I checked the trans fluid and it was just a tiny bit below the full mark. want ahead and added about a pint, which made it over the filled line and managed to climb up.

Here is the climb after I over filled the trans:



Most recently on the Last Chance Canyon trip:

http://www.naxja.org/forum/showthread.php?t=1058063

I again was crawling up a rock and the same thing happened. My trans was at the full level at that time. Should I just plan on running over the full level or do I need to start designing some kind a new trans pan?

Thanks in advance for your help,

Fred
Explorer 1

Just a little below the full line wouldn't be the problem. Know that "overfilling" is not good for the tranny and can complete some frothing and incomplete lubrication. You should "never" have to be above the full line on the dipstick.

Is the fluid RED in color, which it should be? Also should not smell BURNT.

The throttle position sensor is something I would test. It is directly involved with transmission shifting characteristics. Your vintage (87-90) also needs proper adjustment and both testing and adjustment need a manual and a meter.

Good luck!

what happens is your tranny is sucking air when you get on a steep climb, you may need a bigger pan

Redsand said:

what happens is your tranny is sucking air when you get on a steep climb, you may need a bigger pan

Click to expand...

That's my vote. If you're nosing up on that rock, you are probably sucking air. At that steep an angle, watch that your engine doesn't suck air also.

birchlakeXJ said:

Just a little below the full line wouldn't be the problem. Know that "overfilling" is not good for the tranny and can complete some frothing and incomplete lubrication. You should "never" have to be above the full line on the dipstick.

Is the fluid RED in color, which it should be? Also should not smell BURNT.

The throttle position sensor is something I would test. It is directly involved with transmission shifting characteristics. Your vintage (87-90) also needs proper adjustment and both testing and adjustment need a manual and a meter.

Good luck!

Click to expand...

Thanks. I keep my trans serviced regularly, have two coolers and a trans. temp gauge. Fluid is always bright red so I don't think the condition of the fluid is the problem.

The engine doesn't miss or slow down on a steep crawl, the power just stops to the wheels.

I'm tending to go along with the need for a custom pan and maybe a custon fluid pickup from the pan filter.

Looks like I may need to fire up the TIG machine and practice my skill on thin sheet metal or aluminum.

Thanks,
Fred
Explorer 1