Either GM took their chances and lucked out or Ford was paranoid and didn't want issues.
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It will be interesting to see what SkiSkiJason comes back with on the form of heat exchanger embedded in the rad. If it is a single tube as he suspects, it would seem to be not worth the bother.

 

Being third owner, I am not sure. The holes are there but no lines leading to or from.

 

I truly believe it was the former. Those manual transmission Duramaxes are rare as hens' teeth because GM pushed the "Allison" so hard....and truly DID have a winner with it. After The LLY was over, there was no need for a manual as there wasn't a light duty transmission capable of living behind the LBZ. Also, with the FULLY selectable Tapshift on the 2004.5-up Allison transmission option, there really wasn't much need for a transmission requiring a problematic dual-mass flywheel anymore -I have A TON of flywheel bolts for them collected; TTY bolts.The gear ratios of the Allison were actually usable and made sense much like a manual, so why worry about a clutch or the vertical drivetrain speaker coming through the floor?

I mean, why have a manual in a "truck" that has more in common with an El Camino anyway?

 

My 9/98 was a Lariat CC and had know cooler in the radiator. And I bought mine new as well. I added it later.

 

Bonanza35, you have an automatic transmission, which did not come with an OTW cooler, but came with an OTA cooler.

The manual transmission trucks did not come with an OTA cooler, but came with an OTW cooler in the radiator.

 

My e99 (3/98) auto had no cooler in the radiator either.
During my engine swap last week I added a new napa radiator with the cooler provision, now I can utilize that along with my mishimoto 6.0 cooler

 

Okay, thank you on that. Failed to read it right, my fault.

 

I would be hesitant about capping off the lines. The fluid is moved by an oil pump of sorts, (not familiar with the details of the design), but where does the ATF go upon returning to the transmission? The sump? Or the gear shafts to help provide better lubrication for the entire transmission than just relying upon "splash lube"?

 

Technically I will "plug and connect" instead of "cut and cap". Plug the 2 openings in the rad - hopefully with the 6AN I think they might be. And then connect the 2 cooler lines to preserve the loop.

 

This should be an OEM radiator from a 2001 F250/4R100.

Not sure where I thought I saw a much more simple heat exchanger in one of these radiators. Aftermarket? ZF6 truck?? Dream???

 

I am wondering if the straight/single tube might be specific to the man trans. I can see where the focus might be on warming it a bit when it is super cold, while not having so much surface to heat it up from a hot radiator.

Question:do manual transmission temps get as high as auto trans under same conditions? I'm think auto runs hotter.

 

Auto makes a lot more heat than a gearbox. When I first brought my truck home and was rolling around underneath it, I was surprised to see cooler lines on my ZF6. Usually gearboxes don't even have them.

 

Looks the same, as expected.

 

And your thinking is correct.

An automatic transmission has a fluid drive coupling. The fluid itself in an automatic does more than merely lubricate and cool. Rather, the fluid transmits force within the torque converter. Moreover, the fluid in the torque converter resolves the difference between the torque of the engine and the resistance to being turned presented by the otherwise stagnate drivetrain of a weighted down truck. The fluid is also the clutch. All of these extra responsibilities of a fluid in an automatic shear the fluid, and heat it up more than the lubrication and cooling duties of a fluid in a manual transmission.

 

A couple of weeks ago, it seems my embedded manual trans cooler in the rad sprung a leak - thus the root beer float. This was noticed 6 miles after a syncro and bearing replacement on the ZF6. Im guessing that once everything was all cleaned internally, the pump was able to go wild and exposed a 20 year embedded heat exchanger?

As soon as it was noticed, I drained and tapwater+dish soaped it a couple of times, before I had to go on the road for work. Thermostat still in and idling only (with the clutch pedal pushed down) to warm things up. A noteworthy amount of ATF came out that wasnt really emulsified. Of the nominal 6qt that the system holds, I would say 2 qt came out through the rad, while about 4 qts was taken from the trans on initial drain.

After I drained the transmission, it was filled it with 3 qts of cheap ATF, idled with clutch out for 1 minute then drained that.

2 weeks later and I am back to cleaning this mess up. A couple of things to note:

1. In both the initial drain of transmission, the 3 qt drain, and the dregs that came out the plug after sitting for 2 weeks, there was no noticeable coolant in the transmission. The fluid was crystal clear (remember it only had 6 miles on it) through and through. There wasnt a bubble of water in the container I drained it into, nor did I notice anything when I poured the stuff into my waste oil container. How can this be?

2. See photo. This is after the 2nd tapwater with dish soap fill and 15 miles of driving today, 4th total so far including the initial triage (I plugged the rad and capped the lines, I will update a previous post on those details). The first was the same. My initial triage a couple of weeks ago did not look like this at all. The froth in the degas bottle is still prevalent. Aside from the smell of soap, I can still smell ATF.

3. When I went to plug/cap, not one bit of fluid came out the radiator cooling line connection. It is true that I had left the rad drained while I was gone. But when I first triaged the system, I plugged the ports with a small rag (didnt have anything with the right thread) - by no means a tight seal. In fact the first fill/drain, I think I forgot to do that and still nothing came out.

So what is bugging me are:

* why isnt there coolant indicators in the fluid drained directly from the transmission?
* Why isnt anything leaking out of the embedded heat exchanger?
* After 4 full fill/drain sequences - with soap - why does what comes out gray and deeply cloudy still? I do not think it is emulsified ATF. You can see small beads on top of the water. There is no seperation after sitting for 30 minutes (aside from the drops).