1995 F350 crew cab dually 7.3L Turbo Diesel

I would like to install the biggest and badest transmission cooler system in my F350. Do any of you have any suggestions and any good products?

 

The largest I have seen is the OEM cooler on 99 F-series. It is a standalone air to oil cooler used without a radiator cooler.

 

The advice I was given by two shops over 30 years apart and from reading Trailer Life magazine is that you don't want the biggest baddest cooler unless you really NEED the capacity. The reason was that you can over cool the tranny.

I don't think you will damage a cold tranny, unless you live at the North Pole, but the tranny will not shift as efficiently and there might be a little extra wear.

Modern computer controlled trannys had a control that makes them shift a few hundred(500?) RPM higher to warm them up. If you have a super jumbo cooler, they may never get to operating temperature.

The advice I have gotten and read is that you should choose a cooler that is slightly larger than the expected gross weight of the truck and trailer and load. For example if your truck GVWR is 8,000 and the trailer's is 8,000, you should get 16,000 to maybe 20,000, not the 32,000 rated cooler.

My 94 E4OD on a 460 Gas which I use to tow an 8,000# trailer stays normally around 180 to 190 degrees during hard steady towing. It has hit maybe 210 during 70mph+ uphill 100 degree towing a time or two and it did spike once to about 230 right after a hard hot tow and backing in reverse up a slight long hill, ie no real airflow cooling. My truck has the factory auxilliary cooler which is about 12x8x1 and I think is a stacked plate type cooler. The tranny shop said that cooler is enough for my towing needs. I get a little nervous about the few temperature spikes I have seen and might got for either a small extra cooler in line with the current setup(more leak points possible) or replace the current aux cooler with the next size up, but not the super mongo size.

Still it is far worse to over heat than to over cool so if you do get a cooler, it is safer to err on the slightly larger size.

The stacked plate types are supposed to be more efficient and are smaller for the same capacity and cost more. The old style tube types are less expensive and have worked well for decades.

I have used Hayden and Rapid Cool and liked them both. There are probably other fine brands out there.

Good Luck,

Jim Henderson

 

For biggest and baddest you can use an A/C condensor.
They cover just about the whole front of the radiator and work very well.
If you use an old one make sure it is really clean.

 

Hey Jim, I would be happy if mine would run 210. My 460 with a C6 runs in the 240 range all of the time while pulling a 6000lb 5th wheel. I have tried all kinds of coolers and in all configurations. My latest one is a stacked 32k with a Hayden pusher on it. I also run the stock cooler in series with it to try to help. I went up the Baker grade on the way to Vegas last week. The ambient temp was 106 and the tranny pegged the temp guage at 340 3/4 of the way up the grade. I have a temp sending unit mounted in the tranny pan and the guage is a medium quality. This has been a constant problem since the vehicle was new. I have to change the tranny fluid every 12k because it is burnt. It has been this way for over 200k. The only thing I can attribute to it is the 3.07 rear end. Maybe it is making the tranny work to hard.

 

I did this a few months ago on my 85 F-250 460/C6. I was going to remove the A/C condenser to save weight, but thought it looks like a tranny cooler so why not use it as one. I run it after the stock radiator cooler. My tranny still reaches operating temp of 190* it just takes longer to get there. It's also made a notable improvement in towing temps.

 

You woudn't be saving that much weight by removing it.
You can install a pusher fan to help with the temp.

 

Jumped up moses. I'd be looking at ways to keep the temperature lower.
Much much lower.
If the pan fluid temperature is that high the fluid going into the cooler must be well over 400*.
Fry eggs at that temp.

 

A note to consider. The radiator contains the factory tranny cooler. If the tranny gets hot it will heat up the engine and vice versa. A big cooler in front of the radiator can block the radiator and an AC compressor adds to the mix so it's kind of a catch 22. I have seen engines burned up because the tranny temp was running hot.
I have an auxillary tranny coller mounter vertically under the passenger seat with a scoop. I would add an elect. fan if I needed it.

 

Wow, I didn't know a tranny could live that long at those temps. Most of those ATF life versus temperature would show your are really running hot. The Permacool website... http://www.perma-cool.com/Catalog/Cat_page02.html shows that at your 240 cruise the life is 25K or less. At 315 they show the fluid life is less than 2K with mechanical problems occuring, they don't even show 340. Have you ever had to rebuild the tranny? The way the chart reads it would seem that the seals etc should have cooked long ago.

I would probably use a synthetic ATF with your tranny, but that might only be saving the fluid and preventing varnish while still causing problems with seals, clutches etc since the heat is still there.

I would suspect you are right about the low # gearing causing your tranny to work too hard. Most tow vehicles are up in the 3.73 and up gear ratios. 3.07 is city gearing and for mileage(yeah right). I guess this is one of those cases where the biggest mongo cooler you can find is the answer. Maybe you should consider dual coolers? I usually like to avoid more fittings on oil lines since that means more failure points and leaks. But with your rig, those temps are outta site. I haven't had a temp guage on many of my vehicles so I don't know if the temps you see are common. BTW my 460 E4OD 4X4 supercab long bed tows my 8,000# trailer just fine with the temps I mentioned, but it does has a 4.10 rear end which I think helps towing a lot. My engine tachs at about 2,000 to 2,500 RPM at about 55 to maybe 70+ while towing. So this tells me the tranny probably isn't turning that fast so less heat. Your truck probably has the tranny turning fast to make up for the low gears is my guess.

Good Luck,

Jim Henderson

 

I used a B&M Super Cooler on my E4OD. It is a stacked plate design and I chose the "race" version because it uses 1/2" NPT fittings so you can use steel lines all the way. I never liked rubber hoses and clamps, personal preference. It the same cooler that they sell for there engine oil cooler. You can also purchase a remote filter kit.
No problems, no leaks, when I monitored my temp last winter (no load) it was 130-140.
I am very happy with the product.

 

240* ALL THE TIME!! And I panicked a little when I saw my newly installed (test port) gauge crawling above 220* on a recent 2200 mile round-trip to southern Colorado. Twenty plus mph head and cross winds, up hill (800 to 7400'), 93-102* ambient as measured by a grill mounted temp sensor.

I want my tranny to outlast my truck. Even with the OEM HD towing package cooler, freshly rodded out with a pipe cleaner(s), my temps didn't drop once they crept up which told me unless I ... don't make hot weather trips ... travel only at night/early am ... give up pulling my ~7000 lb mid-profile 5th wheel ... drop $30,000 + on a new tow vehicle ... I'm going to have to add a bigger cooler to my old horse.

I agree on the 3.0 gears being part of the problem. I worked where we towed combines on gnecks (14-15,000 #) and the only truck we had C6 tranny problems with had 3.08's. Clyde has 3.55's which handle it well under most conditions but throw in above mentioned factors plus add the effects of altitude and I could use 4.10's also ... but I hate to do it for bi-annual trips. If we did it more often it would be a sure thing. My last set of tires (245/70-16's) effectively changed my ratio to ~3.70 from the OEM stock 235/85's but I really didn't notice that much difference after I went back.

If you've played with different coolers it might be a good idea to play with different axle ratios, especially if you do that much towing.

Roger

Clyde S Dale, my chestnut brown & tan 5th wheel workhorse is a
1984 F250HD XLT RCLB 4X2 8600 GVW
460 C6 3.55's
67,500 original miles (and counting)

 

If you have space under the tranny try a deeper tranny pan. Dont go for the cheap chromed ones cuz there a SOB to get em to seal right. My tranny hasnt gone past 180 since i put in a deeper pan w/25,000lbs tranny cooler.

 

Hey guys, I forgot to mention that I also have the large capacity pan with the cooling tubes going through it. I forgot about it until fordbronco69 mentioned it. The 28K stacked cooler is mounted under the vehicle and I reversed the Hayden fan, on the way back from Vegas, so that it pulled air thru it instead of pushing. It seemed to run a little cooler. It never went over 240 going up the Halloran summit, but the ambient temps wern't as high as the trip to Vegas. I have an extra 18K cooler that I think I am going to mount under the front of the radiator in series with the other coolers and see if it will cool the darn thing down a little more.