Outer Limits 4x4 Board

Hi Guys,
Have a GU with 6.5 chev fitted and 4L80E trans. Trans works great under normal conditions. When towing up steep inclines she will overheat and the electronics shut the gear box down before damage is done. Also when I'm doing low 4wd stuff she will do the same...so obviously when she's working and under load. I've fitted another trans cooler and it has made it marginally better. It's a reasonably slow process before this happens. Any ideas how I can improve or fix this? For example can I fit a trans fan....Any sensible suggestions would really be appreciated. Ta.

have a chat to wholesale automatics.
they might do a valve body that will suit the engine and not work the box as hard.

how many trans coolers do u have and what size.

what trans oil are you running in it, and have you got a fan hook up to your tans-cooler. ive got two trans-cooler plus fan on mine with t700 in patrol best of luck

Thankyou.
I'm running Maxi lite trans oil as spec'ed for gearbox.
I had a second trans cooler fitted, original was the existing Patrol. Size of second one is approx 300mm (12") x (9"). Was fitted by supposedly gearbox experts. No fan to coolers only thru air.

does it sound\feel like the gearbox is sliiping under load.

im thinking the extra power is make the bands slip creating heat and overheating your box.

Maybe try as big of a cooler as you can and with a fan on it, the more passed the cooler has is better also, my auto cooler is a 16 pass core with a thermo on it

Doesn't feel like it is slipping. Pretty firm feel (lol).
Presumably I could get a thermo cooler from a reputable trans place? Problem may be space. Looks like I'll be having a look this weekend.

If you want a good cooler look up tru-cool max cooler by long I just imported one from US for my hilux surf, damn good unit.

Have you got the cooler lines running through the cooler tank in the radiator i would do this first-example why you can cool steel faster in a bucket of water that blowing it with air.
you will find this will be the biggest help to the problem,a big cooler and fan will help inconjuction with this.

Does the TCC clucth in the converter work this is the biggest reliever of heat.

Have you done a flow test on the cooling cicuit to make sure there is no blockages you need about 4lt a minute, if you have low flow the biggest cooler you can can get still will not help.

Good luck.

Hi Modified Toy,Some great advice thankyou. I'll give all you say a check. I know the TCC works as when it is locked heat will go down on gauge and I can see it on the electronic controller. May have to have a play with the Compushift controller as I think you can reduce the speed when the TCC locks which I think would also help in low range applications.