727 Tranny Quest, What is happening?

[80wag]

Ok, 90 model GW with a rebuilt 727. Back in april, tranny overheated on the trail and slipped away, had to leave it for a few hours, came back drove it back home. Now, after installing additional tranny cooler in front of radiator after the rad cooler did another trail run yesterday.

My rig runs a stock cooling system, it gets up around 220-230 putting around on the trail. Going up some steeper stuff it gets close to the top and just quits pulling, it won't spin the tires, just feels like the tranny is starting to slip.

Question is, Could my tranny damage already occured from the last time? Around town it drives fine. I have drained and replaced fluid twice. What causes this to happen when the temp goes up? I am contemplating a TH400 or another rebuild. Also planning on alt. upgrade then taurus fan conversion.

Appreciate your input, suggestions and comments.
Mario in Fort WOrth

[j20brett]

Heat is the #1 killer of auto trannies. Plain and simple. And it is very possible that you killed it that first time. I will assume you at least changed the fluid after you got it that hot. Reroute your cooler lines to do away with the radiator cooler and add a fan to the external cooler and you should be fine.

[80wag]

Thanks for the input, just out of curiousity, how does your rig do with the cs144/taurus fan conv. ? Are you running a stock radiator? So on a summer day with your rig on the trail does your setup keep your rig at 210 or below without a problem? Thanks Mario

[j20brett]

I love the cs144. Ive only got the fan hooked up with low speed right now, and idling with the fan on i never get close to 195. It made it to the middle of the gauge once so far and that was on an extended climb which requireed lots of throttle. Radiator is stock and was just recently cleaned out. It pulls a rediculous amount of air...way more than the mech fan could. Havent tested it on a summer day yet, but i will in 2 weeks when i go wheelin again. I dont forsee any problems with it, and ill have the high speed working by then alos if it does start to warm up.

[Chevelleguy]

I have a 3 core replacement from O'Reilly's, the CS144 and the Taurus fan and mine stays cool too. Never had a problem with overheating even wheeling at Gilmer or Oklahoma with the A/C on.

[80wag]

Good to here from both of you, I am going in that direction for sure. My radiator was replaced before my rebuild, it runs about 195 but on the trails it creeps up to around 220, no more I hope after the upgrades. Thanks again. Mario

[mattmopar440]

Larger deep ALM pan and Synthetic fluid electric fans should do it