I don't see much benefit in OTW "cooling" - I think your money would be better spent installing large AT oil to air cooler like for example in F250 & F350 with 6.0 engine.

I did that couple of years ago on my 99 F350 and it was a very good fit.

 

Do you have any testing to back that up? I have plenty. The oil to water cooler.makes a HUGE difference.

 

I put both the water cooler and 6.0L trans cooler in my e99, works great together.

 

I am curious - are you monitoring the AT fluid temperature?
Are you pulling a heavy load?

 

arto_wa...

I monitored AT fluid temps using two different methods simultaneously... an NGS that I borrowed from Ford (I own my own now) and an independent gauge plumbed into the pressure port. This was back in 2001, when I had transmission fluid temp problems with the stock OTA cooler and no OTW cooler, as configured by Ford at the time.

Since the 6.0 cooler hadn't been invented yet, I changed OTA coolers to the V10 cooler, which as your photo aptly demonstrates, isn't nearly as dramatic of a difference in heat exchanger area as the 6.0 cooler.

Yet, the difference in my fluid temps before and after my cooling system overhaul was VERY dramatic, as measured and confirmed with two instruments that agreed with each other. I attribute the dramatic change to the fact that at the same time I added the formerly missing Oil to Water cooler.

Water is a more efficient heat transfer medium than air. As a different example, the Banks diesel race truck used an oil to water intercooler to lower the intake air temperature in order to increase air density to get more power per pump. Racing is all about lighter weight, but the cooling efficiency of water, as opposed to air, was worth carrying the extra weight of additional cooling water just to cool the compressed intake air. A larger air to air intercooler would have been a lot lighter weight, and less complicated too, but not as efficient at dropping the temps.

Back to cooling the 4R100... in the 14 years since adding the OTW cooler, and monitoring trans temps with a permanently mounted independent gauge, I have not seen the need to upgrade to a 6.0L cooler (from the V10 cooler I currently have installed). I would say it is definitely worth getting the oil to water trans cooler, and plumbing the cooling lines so that the hot fluid is routed through the OTW cooler first, then the OTA cooler, then back to the trans.

 

What Y2KW57 said. Here in California I never see over 165, usually 145.