My setup: I had my E4OD tranny rebuilt "bullet proof". Two add on tranny coolers were installed in front of the a/c condensor, radiator tranny cooling eleminated (shop will not warranty tranny when using radiator as internal leak could put water into tranny). Truck has the extra capacity radiator for cooling. Stock clutch fan.

My issue: The tranny normally runs very cool, can drive all day and tranny temp will not exceed 140*. I have never had an overheat issue with the engine, even when pulling heavy loads up hill. But, the tranny temp will rise, and will exceed 200* when pulling heavy loads up hill at slow speeds. The engine temp will barely rise, so I don't think the fan clutch is engaging for added cooling at the slow speeds. If I get up to hwy speeds, or down hill, the tranny temp will drop again (more air flowing through the coolers).

Solution? Is it possible to replace my clutch fan with a 6.0 electric clutch fan and wire it to a tranny temp switch to engage when the tranny temp rises?
I've found what looks like the wiring diagram for the electric, but it looks like it's not a simple power input to lock up the clutch. These are apparently computer controlled. Any way around that?

Thanks.

 

I added a 6.0 fan and dissaster struck (it hit the radiator). That tranny temp is practacly normal, if your concern about it add a 6.0 transcooler and plumb back to your radiator.

 

Using the radiator cooling is a must, I don't think your shop knows what its talking about. Also running two coolers together restricts flow. Never heard of a extra cooling radiator. If the engine temp barely rises then you fan clutch is working fine. Its been tested a few times on here using electric fans and they just don't work as well as our stock setup. Lock up the clutch?? You mean a temp control to activate the electric fans? The clutch is activated by oil inside of it.


Edit: Like adam said, get a 6.0 trans cooler.

 

I don't want to harp on what was said here but this does not make any sense to me why a trans shop would do that. That in my opinion is worse than a stock cooler unless I read wrong, but apparently it must be working ok if you are not pushing over 200. Hopefully they did not rake you over the coals for the bullet proof build either.

I am by no means a tranny guy, but from experience you see a lot of what does and does not work. Mark K. over on the SD section was a transmission design engineer for FORD for nearly 20 years i believe. If there is any answer to be true, it would be one of his. Might be worth shooting him a PM and explaining your situation and components you currently have.

The best cheap mod for your 7.3 is to run a 6.0 cooler 26 row or 31...the 26 is the newer design and should be preferred.

I'm not sure what you are towing in regards to heavy. But we have multiple fleet 7.3 trucks that pull double tandems and range anywhere from 22-28k gvw and can not push the trans over 200 degrees. Around town they are around 145. 200 is not going to hurt a thing!

 

I would ditch that whole cooling setup and plumb back to the radiator with a 26 row 6.0 cooler. Then go slap the trans guy.

 

 

Solution? I don't even see the problem. Getting over 200F on a hard, slow pull is absolutely normal.

I wouldn't do that. The trans guy is partially right. I wouldn't warranty a new trans that used the same cooler as the old trans, either. Junk from the old trans is in the old cooler, both and air to oil and the cooler in the radiator. There is NO effective way to get all of the junk out of the coolers. Sooner or later something is going to come loose and end up in the new trans, possibly causing a failure.

The best solution to have the best trans cooling is to replace the radiator with one that has a trans cooler, and to replace both coolers you now have with a cooler from a 6.0L truck.

 

I can relate to that Mark, I blew up a trans and the transmission guy said to buy a new radiator. He said that he couldn't get it flushed good enough, even flushing both ways it was full of junk. I wasn't very happy but bought a new radiator.

 

Mark,

I have another of those questions you've probably answered 500 times. Is there any advantage to installing an external transmission fluid filter? One of the alleged guru's told me it's a waste of time and money since the transmission already has an internal filter. He said that any wear material in the fluid is going to be magnetic and a magnet in the pan is better than a filter. Any thoughts on this?

Thanks

 

Most of the wear material is clutch friction material. It isn't magnetic. A filter is a good thing as long as it doesn't increase restriction enough to cause a problem. And no, I don't know how much is too much.

 

I just installed a new Mishimoto radiator and TruCool cooler. To protect them, I installed a B&M filter kit that uses a screw-on filter. The new filter gets oil directly from the tranny on the way to the coolers. Hopefully, if my tranny crashes, the new filter will catch all the debris. For 50 bucks or so, plus a $5 filter once in a while, it seems like a good investment.

 

I think it is a good investment, as long as the flow resistance isn't high enough to open the cooler bypass valve. If it is high enough, you'll see the trans temp creeping up.

 

Mark, are you saying the tranny has an internal cooler bypass valve that routes the oil back to the tranny if the line going to the radiator/cooler has a restriction that exceeds a certain level? That's interesting to know.

 

Yes, that's exactly what I'm saying. It's actually on the outside of the trans. It's the tube between the two cooler lines on the side of the trans. I don't remember what year it was added. I know all 4R100s had it, I don't know about the E4OD.

 

I don't think it's on the E4OD. Mine just has the two lines coming out of the side.