Transmission cooler for an AT 545

[Rivetboy]

This is being installed on our 1991 Bluebird tc 2000 28 foot.
The fan cooler is a Derale 50 K BTU (don't quote me on the BTU's)from Summit as all of the Aeroquip A/N hardware.
It is fun not to be working on the motor for awhile. although the engine needs wiring and intercooler and radiator installed plus fluids but it is close. Also, have decided to move the shifter console to the right of the steering wheel. There was a metal box on the right that came out and left a big hole for the shifter assembly. Friday it will be plumbing it up. The hangars that were used to mount the cooler to the frame rail were salvaged from the tail pipe hangars when the tailpipe exited through the bumper.

[Mr4btTahoe]

Derale makes some nice coolers as does Longs. I run a Longs Tru-Cool 40k Max rated for 40k gvwr. 45k btu rating without a fan. Have had great luck with them.

Very nice install btw.

[Tango]

Can't tell from the pix, does that unit have a fan? If so, will you be wiring it up to a thermostatic switch?

[Rivetboy]

Thanks what a fun project

[Rivetboy]

Yes it does will be using a 190 degree on 175 degree off switch located between the oil filter and the return port. Also, a temperature sensor for supply temperature and one for return temperature.
The oil thermostat valve also opens at 190 degrees.

[Tango]

Excellent. I still need to get my switch, plumb & wire mine. Nice job!

[Rivetboy]

Thanks for the kind words
I love Summit most of the time it is next day service for me

[Tango]

I like both Summit & Jegs but got my cooler from Earl's after a custom car builder recommended their goods.

[Rivetboy]

I am wondering if the 190 deg/175 deg split will be too much. It might turn on and never turn off. Might have to experiment with sensor location and range.
Where the heck is the PID loop on this thing?

[Mr4btTahoe]

Originally Posted by Rivetboy

I am wondering if the 190 deg/175 deg split will be too much. It might turn on and never turn off. Might have to experiment with sensor location and range.
Where the heck is the PID loop on this thing?

I dont think you'll have any issues with it if the cooler is not looped with the radiator cooler. My 40k keeps my built 4l80e under 140 in the middle of summer with no fan. I'd say the only time the fan will kick on will be pulling hills and such... but only time will tell.

[Rivetboy]

Its looped with the radiator cooler but through a 190 deg isolation valve thermostat.

[turf]

congrats on the trans cooler!!! i was very happy with the mine when i added one too.

i'd be sure to run a 190* thermostat. that should make sure you reach that temp for the bypass. last time i went to napa the they gave me an option of 180 or 190*.

the thermostat i put in was a 180* and my rig runs cooler. i dont have a bypass like yours so my temp is what it is. my trans temp gauge reads cool most of the time.

nice looking job!

[Rivetboy]

Thanks, I am excited to see what happens too!

[mikerob643]

Is a transmission cooler a pretty necessary thing on busses ? I'm just starting to outfit my bus and am now wondering if i need to add a aftermarket transmission cooler to my must have list ?

[Twigg]

Originally Posted by mikerob643

Is a transmission cooler a pretty necessary thing on busses ? I'm just starting to outfit my bus and am now wondering if i need to add a aftermarket transmission cooler to my must have list ?

With an AT545 in hill country, I'd want extra cooling.

For the others it's "nice to have".

Keeping the ATF below 200F extends its life and reduces wear on the transmission.

People's circumstances vary. Some of us live with very hot summers, and cooling systems benefit from a little extra help.

[mikerob643]

Originally Posted by Twigg

With an AT545 in hill country, I'd want extra cooling.

For the others it's "nice to have".

Keeping the ATF below 200F extends its life and reduces wear on the transmission.

People's circumstances vary. Some of us live with very hot summers, and cooling systems benefit from a little extra help.

Thanks for the info Twigg, I think I will definitely add one on. We are going to be in the mountains at least 80% of the time and anything i can do to stave off the dreaded tranny rebuild sounds great . When I decided on the exact cool ill post photos of the install !

[turf]

long grades up and dangerously fast descents are the death of the AT545. this transmission never locks up, which means as you climb the hill, the rpm's stay the same, but you start slowing down to just a crawl if the hill is steep enough or long enough.
the difference between the rpm's and the ground speed is slippage of the transmission. slippage creates heat, heat kills fluid and transmissions.

on my run just prior to adding a transmission cooler, i cracked my exhaust manifold, running to hot, up Monarch Pass in the colorado rockies.
the cooler was better than adding a turbo. i have power to climb hills, downshifting and acceleerating up hills....it made a huge difference.

[mikerob643]

Turf, its good to hear that the cooler made a big difference. Which one did you go with ? I am looking at them now and trying to decide which would work best for the Allison tranny

[mikerob643]

Originally Posted by Rivetboy

This is being installed on our 1991 Bluebird tc 2000 28 foot.
The fan cooler is a Derale 50 K BTU (don't quote me on the BTU's)from Summit as all of the Aeroquip A/N hardware.
It is fun not to be working on the motor for awhile. although the engine needs wiring and intercooler and radiator installed plus fluids but it is close. Also, have decided to move the shifter console to the right of the steering wheel. There was a metal box on the right that came out and left a big hole for the shifter assembly. Friday it will be plumbing it up. The hangars that were used to mount the cooler to the frame rail were salvaged from the tail pipe hangars when the tailpipe exited through the bumper.

I was wondering if you think it makes a difference to mount the transmission cooler under the bus right by the tranny like you have it or mount it upfront in front of the radiator like i have seen on other installs? I don't know if there would be a large difference in the cooling ability or not.
I am looking at installing a Deral 9000 series cooler without the fan so airflow might be more crucial for me.

[turf]

i got a used cooler from an online junkyard.

i think new would be just the same cost as i paid for used.

my cooler thread:
http://www.skoolie.net/forums/f33/ad...545-14363.html