"normal" AW4 temperture

I recently put a tranny temp gauge in my ’91 4.0 auto with factory 2 row radiator and internal tranny cooler. I put the sensor in the “in” line for the tranny cooler (top hole on cooler, hi pressure side from tranny) so I can see how hot the fluid is coming out of my tranny. My gauge reads from 100* to 250* with 180* being in the middle. In 2 wheel hi running around town my tranny stays right around 180*. When I put it in 4 hi and start playing in the snow it will quickly jump up to 220*. This kind of alarmed me since the gauge only goes to 250* and I would assume that is the max temperature. Does anyone know what the “normal” operating temperature is for an AW4?

180 is pretty much ideal operating temp. if I remember my research correctly. was always under the impression (an assumption) above 240-260 or so the oil starts cooking a bit, color will change. What your measureing is just an indicator, right at the clutches, things can get a lot hotter.
Chev sometimes pumped the hot oil (against the flow) from the bottom, to the top of the radiator heat exchanger, never did figure out why, could be more effiecient that way, could also have something to do with the plastic radiator ends. Engineers had there reasons. Maybe it just helped get everything up to operating temp. quicker.

Wiley Coyote said:

I recently put a tranny temp gauge in my ’91 4.0 auto with factory 2 row radiator and internal tranny cooler. I put the sensor in the “in” line for the tranny cooler (top hole on cooler, hi pressure side from tranny) so I can see how hot the fluid is coming out of my tranny. My gauge reads from 100* to 250* with 180* being in the middle. In 2 wheel hi running around town my tranny stays right around 180*. When I put it in 4 hi and start playing in the snow it will quickly jump up to 220*. This kind of alarmed me since the gauge only goes to 250* and I would assume that is the max temperature. Does anyone know what the “normal” operating temperature is for an AW4?

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To quote my buddy who runs a very reputable tranny repair shop (didn't know there was such a thing, right?) you want your fluid temps to stay between 180 and 200 to keep the tranny happy and the fluid from breaking down. If you happen to get it into the 240 range for a time, you should change the fluid asap thereafter. This is best case scenario.
On the flip side, most folks really neglect servicing their auto trannys and he says that he rarely see's AW4's in for repair, and then usually after they have a couple 100K miles on them, so the unit is built well.

I installed my trans temp sensor in the right front corner of the pan and have occasionally read temps in the 220-230 range after some hard pulls in the sand and snowy climbs and that's with the intank cooler and an oversized aux tranny cooler inline.
Deeper pan and aux cooler will help keep the temps down.

First time posting. Thanks for the good info.
I recently took the interior out to do some cage work and noticed how hot it gets, you could cook a steak on the floor board, around the tranny. I have noticed a lot of heat before while creaping along in 4 lo with the carpet in but since I'm new to the rig figured it was normal. Is this normal? Would an additional tranny cooler fix this? Is this a bad sign? I have not looked closely at the AW4 but some auto's have existing locations for a temp. sendor. From the location previously described I guess the AW4 does not. A deeper pan was mentioned is there one available?

Sean

seanman said:

First time posting. Thanks for the good info.
I recently took the interior out to do some cage work and noticed how hot it gets, you could cook a steak on the floor board, around the tranny. I have noticed a lot of heat before while creaping along in 4 lo with the carpet in but since I'm new to the rig figured it was normal. Is this normal? Would an additional tranny cooler fix this? Is this a bad sign? I have not looked closely at the AW4 but some auto's have existing locations for a temp. sendor. From the location previously described I guess the AW4 does not. A deeper pan was mentioned is there one available?

Sean

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A deeper pan is available, with the help of your welder. Take teh pan off of the junk tranny in your side yard, cut the topp off of one pan, and teh bottom off of the other one, and then weld the two remaining pieces together.

Search for username "GoJeep", that crazy Aussie has done just that.

CRASH

I'll put that on my to do list. Or maybe URF will be free one evening and produce one.

Sean