trans temp ?

[mkoch1]

I need to set the temp at which my trans pump kicks on and starts pushing fluid through the trans cooler. Can any one tell me what a "normal" operating temp is and what temp I should turn on the pump? Trans is a g50/50 LSD 5 speed.

mark

[jschwartz]

Mark,
You may want to check with the manufacturer of the lubricant you're gonna use. I'd say you want to turn it on about 250 deg F.
Jeff S

[osborni]

One thing I've wondered about trans or engine coolers. Wouldn't you want them to turn on at a lower temp so that you don't thermally shock whatever they are cooling?

Say the max oil service temp is 280 Deg F and you turn the cooler on at 250 Deg F, you could run ambient (or close to) temp lubricant through the tranny or engine when it should really see 250 deg F oil.

Shouldn't you turn it on at more like 180 or so so the temperature delta isn't as high?

The time to get all the fluid up to temp should be the same since it has the same thermal mass either way, you just reduce the thermal shock of turning on the cooler at a higher temp the first time.

Shouldn't there also be an override so you can open up the bypass earlier to get warmer fluid in the cooler sooner if you know that the cooler will have an intermittent cycle?

I guess it depends on the duty cycle of the cooler and the engine or tranny should be up to full temp with all coolers running or at least running intermitently prior to really loading it up. Thermally shocking a piston wrist pin or syncro would generally be bad at load - unless the effect is so small or the oil has plenty of time to get up to temp interally prior to hitting a critical part.