Tranny cooler in the Minnesota winters....

[mrtosh]

I just bought a '98 XJ. My third XJ, but my first AW4. I'm looking to put a B&M aux. cooler in but am wondering if it's ok to have one in the winters we get here(sometimes 30-50* below 0). I've heard you can still run it through the radiator and get some heat exchange, but my question is is it best to plumb it: tranny-cooler-radiator-tranny or: tranny-radiator-cooler-tranny? Remember I'm looking for all the cooling purposes of a aux cooler, but still want it to be safe to run in cold temps...

Thanks in advance guys,

Sean

 

[codyj86]

I only run my trans cooler in the summer months. i switch it sometime in spring and fall. it's not difficult to switch, two hoses....

 

[snow580]

Hey my Minnesota neighbor!
The way I've always been told to is tranny> rad.cooler> aux. cooler> tranny.
I guess I see no reason too disconnect the aux. cooler in the winter time.
Hope this helps!

 

[xjtrailrider]

After the cooler, route the lines back through the radiator then to the tranny. That will put some heat back into the fluid before it reaches the tranny.

Block off your grill in the winter time. My 90 runs "too" cool due to the closed system being so efficient so even in our mild winters I have to block off the grill, as a side benifit I've noticed my tranny runs slightly warmer(via B&M tranny temp guage)and warms up faster. I just remove the grill and zip tie some cardboard to the inside of it and re-install it. That silver insulation stuff you can buy in rolls at Lowes or Home Depot will work as well.

 

[FransWhiteXJ]

You could also install an in-line thermostat, which only opens when the fluid reaches a preset temperature.

Fran

 

[badron]

Cover 3/4 of the rad by 30 deg F.. You most likely have block heater(s) and a covered rad will help keep the engine warm and the E bill down. The engine will warm faster on cold starts and stay warm longer after key off. Covering the rad and trany cooler will help in many ways.

 

[boomhauer]

No worries running it in the winter, i actually recommend it, especially if you like to play in the white stuff. -B

 

[Muad'Dib]

tranny-cooler-radiator-tranny

Thats the way it should be done.

Tranny output to
New Cooler to
Heat exchanger in radiator back to
Tranny.

 

[broqenjeep]

tranny temp at least 170 otherwise to cold and can be harder on the transmission than to hot (210) mine goes to the radiator then the aux and back

 

[mrtosh]

tranny-cooler-radiator-tranny

Thats the way it should be done.

Tranny output to
New Cooler to
Heat exchanger in radiator back to
Tranny.

Soo routing it this way is still going to keep it cooler? Probably not as cool as tranny first, then aux cooler, right? As long as it can keep it cooler yet not allow it to get too cold in the winter....

 

[boomhauer]

tranny temp at least 170 otherwise to cold and can be harder on the transmission than to hot (210) mine goes to the radiator then the aux and back

Please explain how that could be? I know heat kills the AW4. I run a trans temp gauge on the hot and return lines. The trans will always warm up. Winter has never been a factor and we had 40+ days this winter with -30c. Put your cooler on and don't look back. -B

 

[Standard]

I've had no issues with my tranny/tranny cooler.

On a side note, covering the grill should have no real effect on coolant temp as long as your thermostat is in good working condition. If you're having issues with over-cooling it's probably because the thermostat spring is getting weak and not closing all the way, letting coolant bypass. My '99 only takes about 5 minutes to fully warm up even on the below zero days.

 

[Muad'Dib]

Soo routing it this way is still going to keep it cooler? Probably not as cool as tranny first, then aux cooler, right? As long as it can keep it cooler yet not allow it to get too cold in the winter....

The bottom line is yes... there is a lot involved here however. Sure it could run cooler (i think ideal operating temp of the tranny is 180F) if the exchanger was bypassed altogether.... however in your situation, you want to keep that fluid warm during the colder months, so this routing is ideal.

My personal opinion is its better to run the tranny too hot then too cold. Although with a good tranny cooler, it will never get too hot. Mine runs about 180-200 depending on the conditions... and i DO run the return through the heat exchanger.