Aux. trans cooler? When?

Makes a aux. trans cooler in addition(seriell) to the stock cooler (intergrated in the raditor) sence on a stock 351M/C4 drive train, no race and no towing, no opperation in winter, but at higher speeds (85-90 mph for longer periods)?

Can the fluid be too cold and cause damage or unusually wear?

Thanks

If you use both the radiator cooler and an auxillary cooler you can't get it cold enough to damage the transmission. You should run your transmission between 120F and 180F. That is warm enough to get rid of any condensation without getting warm enough to hurt the tranny.
In my opinion the first thing that you should do to any new car with an automatic is add the biggest cooler you can mount in front of the radiator. If everyone did that most of the transmission shops whould go out of business in three years. Over 90% of all failures are due to overheating the transmission. With a big cooler you can drop the temperature up to 60F which will extend the life of your transmission to eight times what you could expect from the stock configuration. It is the best thing you can do to make a transmission last longer. Add to that oil changes and band adjustments every 20000 miles and your transmission will outlast your engine.

I second that. I could not say it better.

thanks a lot, forgot to say, it a 77 Ford Ranchero GT.

Will install the aux. Cooler. Thanks again

Any time we can keep another Ford on the road is thanks enough.
Happy motoring......