[Duke]

While going up the ledge shown above at a relatively slow steady crawl my front end got light and lifted off the ground. I've been told my front tires were about 2' from the ground although it didn't feel that high. There are no pictures as everyone was running for cover as the general thought was I was going over.

The odd thing was that for those few seconds I had no tranny control. When I touched the gas to try to provide some throttle input the motor reved, but nothing happened. I had no forward or backward power from the tranny. Luckily the truck settled down on its own accord and as soon as everything was at reasonable angles (all wheels back on the rock face) I had control again.

My JK is a '07 Rubi with an auto. I have wheeled two other auto equipped vehicles (and several manuals) in similar terrain and never experienced any sensation like this.

My initial guess was that tranny fluid pickup was exposed and sucking air. Does that make sense? Or maybe since the JK is computer controlled, it was taking over? Thoughts?

 

[Gib]

I'd bet your first guess was right on. I remember that TJ's had this problem with some of their automatic transmissions. The cure for it was a deeper pan and extended pickup. More fluid in general in order to alleviate the problem. You could try to put in an extra quart or so and see what happens.

 

[Guest]

I have no idea as to whether this makes any sense or not, but is it possible that some of the electronics in the ESP system sensed that you were near rollover and kicked in?

 

[PhilD]

I have no idea as to whether this makes any sense or not, but is it possible that some of the electronics in the ESP system sensed that you were near rollover and kicked in?

Could be, but I don't think so, the vehicle came forward and then lost power, leaving the front wheels in the air as it almost jumped backwards. It looked like it just lost the tranny for a moment. I would have thought if it was the electronics it wouldn't have allowed the engine to rev like it.

 

[Gib]

If you had it in low, the ESP wouldn't cut power anyway. I'm pretty sure you sucked air for a second. Put an extra quart or so of fluid in it then try that spot again.

 

[jdrogers]

I'd bet your first guess was right on. I remember that TJ's had this problem with some of their automatic transmissions. The cure for it was a deeper pan and extended pickup. More fluid in general in order to alleviate the problem. You could try to put in an extra quart or so and see what happens.

When the 42RLE first came out in the 2003 TJs there was a problem but it's been fixed with a redesigned pan/filter assembly.

It is NOT a good idea to overfill the transmission. This causes several issues (fluid foaming, etc.) and the service manual warns against doing it.