After the coast clutches failed in my 4R100, I had a BTS installed by a really good local outfit that works with Brian. For reasons that don't make any sense now, I opted to keep my Tru-Cool cooler, rather than going to a 6.0 one. The transmission has been great for the two years I've had it, and still is. The guy that installed it mentioned that the BTS' tend to run a little hotter than the stock ones, and I've seen that. I don't baby this one like I did the stocker, and that may have something to do with it.

Anyway, I've seen something odd, and would like your opinions: The tranny temp doesn't seem consistent, and sometime seems way hotter than it should be. For example, on a cold morning last winter I drove thirty miles to a friend's house on highway and 65mph two lane roads. The tranny temp hit 180*, which I thought was really high. I made the same drive the next morning, with a slightly warmer ambient temperature, and the temp only hit 140*. This has occurred a few times since then, though less dramatically, and in situations that weren't as easy to replicate.

What might cause this? I'd be willing to spend a little to protect my investment, but don't want to just blindly through parts and money at it.

Thoughts?

Mark

 

I'm stoopud when it comes to trannies, all I've got for you is my experience with my HD4R100. I always get about 70 degrees above ambient temperature, which means the only way I'd see 180 degrees is if I'm on a hill towing, or I'm someplace unpleasant. I think Brian needs a call - and ask him about your transmission shop, while you're at it.

 

I would go with the 6.0 cooler. The 6.0 is still way bigger and more efficient than your stock cooler and true-cool cooler combined. When I got my truck it had the stock cooler and 2 B&M supercoolers. I removed the three coolers and replaced them with the 6.0 cooler only and my temps went down aprox 20 degrees. I personally would not trust anything other than the 6.0 cooler protecting my $4k+ transmission(if I could afford one). The 6.0 cooler is crazy expensive but so is your BTS! I would also give BTS a call.

 

Do you have a cold weather bypass system installed with your trans cooler?

 

When I got my BTS I had a tru cool and yes I noticed a 10-20* jump from stock temps, but after the 6.0 cooler install my temps are back to normal.
Hauling my 5'r in 90*+ temps I never see over 190*
I would check the gauge if you have fluctuations like what your seeing.

 

The warmest temps I have seen in my trans were in the middle of winter, -10°F ambient, 2 lane road towing a 4k trailer. Temps hit 190° that day. Towing my 10k 5th wheel this summer in 90+ heat I have only seen 180° on 2 lane roads. My trans was rebuilt locally with the full Tugger kit and a triple disc converter and I also have a TruCool and stock cooler.

 

https://www.ford-trucks.com/forums/8...pass-line.html

Cooler Plugged? Maybe the pressure by-pass is not allowing the cold thick oil to flow to the coolers during the winter?

 

I always have a hard time understanding why people would much rather do all the plumbing work and mounting for a tru cool, rather than go with a bigger, better, and drop in, 6.0 trans cooler. Yeah, you'll spend more money, but it's much easier to install and pays for itself in the long run...

Eliminate both the stock and tru cool trans coolers and get yourself a 26-row 6.0 trans cooler. It makes all the difference when it comes to temps. Be it driving around town or towing, it will keep things cool unless you severely overload the truck.

 

IMO, I would not eliminate the in radiator cooler, backing and at slow speeds (stop and go driving) it is the only cooler that is doing anything. There is a reason Ford went from air only cooling to an in tank cooler with air combination.

 

Thanks guys. I think I need to bite the bullet for the 6.0 cooler, and that's actually why I posted the question now: Additional cooling is good, but doesn't necessarily address the variability I'm seeing. I'm trying to find out from you guys what else I ought to do at the same time. Replace the bypass lines? Something else?

Also, is it worth doing a flush, even after only 12000 miles? How about installing an in-line filter (with its additional restriction)?

I don't think cold tranny fluid explains what I'm seeing, as the truck (Excursion) sits in a garage that never gets below 56*. The gauge/sensor could be faulty, but it doesn't display any other symptoms of that: Indicated temps don't change rapidly, they are not wildly off the charts for a given situation, etc.

Mark

 

It never hurts to do a flush....

The additional magnetic inline filter doesn't hurt or restrict the flow either. I've been running one since April 2006 and my trans is in awesome shape.

Here's from when I took the filter off and cut it open:




The magnet clean:


The filter:


The magnet covered in shavings and magnetic filth:








Needless to say it MORE than did it's job....

 

I'm now the proud owner of a $315 6.0 tranny cooler, or at least I will be when I pick it up tomorrow. Interesting process buying stuff from dealers...

Toreador_D, did you use a 3/8" filter? Is it on the return or supply line (with respect to the cooler)? I'm thinking of using 1/2" line like Woodnthings did, but I assume it must be reduced down to 3/8 at the hard lines, and that's where the filter goes, correct?

Mark

 

Mine is upfront just after the cooler, I don't remember which line it's on, but it is indeed a 3/8 filter I'm using.

I'll have to look to see which line it's on...