That would be my guess. Mine was at 120,000 miles. Coolers only work if the fluid makes it through them.

 

That's the one I have.

 

Sorry I was asking Whitesford & Muckster, they said they are running Tru Cools. I have a 6.0 cooler myself, but I just threw a Tru Cool 4739 on my Chevy work van.

 

One thing I didn't like about the Tru cool was the inverted flare fittings they give you are not even 1/4" ID. I went to a hydraulic shop and picked up a couple that were bigger by 1.5mm hoping to increase the flow, can't see running 3/8 line then choking it down to 1/4" at the cooler.

 

It sure will! If the trans is slipping it will get HOT and fail completely, probably within 1-2 miles. You're not running down the road with trans slippage because it won't live like that. It just dies.

 

Now that's getting pretty hot. It's 50°F hotter than you said before.

Do you have a cooler in the radiator plus one or two air to oil coolers? Along with the external filter you may have too much restriction in the cooler circuit. That will cause the bypass to open and you'll get little or no flow to the coolers.

No, that's not high. The trans was designed to operate at about 170-180°F.

 

Mark,

A bit of a thread hy-jack here.........

When my TC went out a few years ago it clogged the radiator cooler. After replaceing the TC the radiator cooler was bypassed and I only ran the 6.0L cooler while living in Southwest, OK.

Now that I live in South Dakota I ran into the opposite problem - getting the transmission warm . the -20F degree days were nasty. In March my Used Oil Analysis of the transmission fluid showed some high wear metals so I took it to the shop and they dropped the pan for a fluid flush & inspection. To make a long story short - there were metal fragments in the pan and after the dissassembly the main support bearing was the culprit. Caught it early enough before it trashed anything else.

After the repairs the shop recommended hooking up the radiator cooler to a hot flush machine in order to clean it out and get it hooked back up in series like it was before. All seems to be good the last 3 months and pulling the camper & boat on some short hauls.

My question is......

How effective are these hot flush machines in this application? I was always under the assumption that once a radiator cooler is clogged it was bypassed . According to my trans temp gauge the transmission seems to warm up quicker during the cold spells and keep it around 80-90 degrees above OAT when towing the 5th wheel. All seems to be good - just wanted your advice/opinion before pulling the camper on some big trips again.

Best regards,

Rich

 

Thats the same tru cool as I have, the 40 k one.

 

I always understood that a rule of thumb was 100 degrees plus ambient temperature. I never see over 200. Thats setting in traffic for extended periods of time on a nice hot & humid day here in Louisiana. Usually i range from 150-180 unloaded. I'm hoping that my stock setup will get me by til i upgrade to a BTS. Are aftermarket coolers advised with a BTS?

 

I dont have the radiator cooler, i dont think anyway. I just have the one air to oil one, and I plumbed the tru cool inline with that one.

 

Just lining up some links for you in case.. I just had the same thing out of the blue ( except of course for the ridiculous length of time between change ) and the temps stayed way high. The thing I took it for granted for so long I never really noticed the gauge after a while, so all of a sudden seeing it move caught my eye. The truck used to run no hotter the 150 here in miami in the summer, and I was pushing 175 - 190 after I did the fluid change and filter. I did have a flush problem when I changed the filter and fluid, which I then retested to be the stuck bypass valve, and replaced that last night. Thanks in advance to all those who posted the links before me.


Fluid Change (again):
Changing ATF Fluid in a E4OD and 4R100 transmission .: Articles


This is where I tested my valve
Diesel site bypass valve :
http://www.dieselsite.com/index.asp?...ROD&ProdID=172



From springerpop for bypass valve rebuild:

Sonnax makes one:
http://www.sonnax.com/instructions/36605-02K-IN.pdf

Available here:
http://www.transmissionpartsusa.com/...0502K&CartID=1
for $8.71

 

You should have the oil-to-water trans cooler in the bottom radiator tank. My '01 F250 has one and your truck is the same a Rick's (miller_feed). He has it also.

 

FWIW, Brian installed a 6.0 cooler on mine when he put in the tranny.

 

was that included in the price?

 

Brian was good with my Tru-Cool cooler. He just wants you to have that or the 6.0 cooler.