Got it back with good news.

I'm happy to report that the Doorman Part # 265-811 pan which is really cheap, FITS.

Proof, under a 2003 Chevy Blazer since I've been incapable of finding a picture of this pan installed on any other 'blazer' that isn't a 'trailblazer'.



On the line item for its install they also listed a 14 quart fluid flush which is odd since they originally were going to charge me $200 for a flush and $200 for dropping the pan alone, guess I got what I wanted anyways...?

As for the Dexcool saga, they seem to have installed the new radiator cap I left with the rest of the parts but forgot to tell them about, line items show an exchange and flush, when asked they said they were using the BG machine and thus their chemicals too I'm sure. Hopefully its cleaned up well enough!

Next up is the diff fluid, going with Mobile 1 there, any objections...?

How do I go about doing the front diff fluid exchange too? I've searched about but see nothing really explaining it in non-simplistic "pull the drain plugs" means, I need to know where the plugs are and how to get to them and what I need to remove if anything to get there, as well as any tools I might need since I'm oh so poorly tool deprived and rather buy it ahead of time.

After that, trans cooler, but I still need to know if the top or bottom on the heat exchanger built into the radiator for the trans fluid is the outlet?! I really want to put my aux cooler AFTER the built in cooler.

 

The upper transmission cooler line on the radiator comes from the transmission. The lower line, (return) is where you install the add-on cooler. Provided the add-on cooler has a enough cooling capacity, totally bypassing the OEM cooler in the radiator will reduce fluid temperature even more.

 

I'm really tempted to do that, its the 13,000BTU unit Supercooler from B&M, but I also don't want to lose the 'warm up' ability of the built in heat exchanger for cold weather, sorta varies between 110F and freezing here :P

My goal, since the coolant temp seems to stay at 190-200F all the time (its been warm here, 103F today) is to try and have that as -20/30F for the trans, 180F~160F

Trying to make things as reliable, easy to service, and efficient as possible without straying too far from "OEM" style arrangements.

 

I have installed several Imperial, (Hayden) #243012 coolers and eliminated the OEM cooler. Trans fluid operating temperature remains ~60F above ambient. With a 110F ambient, trans fluid would be right where you're looking for it to be. If you're concerned about fluid temp being too low in the Winter, switch the hoses in the Fall so that the fluid passes through the OEM cooler first. Ambient temps around here this past Winter were below zero many times and I never had a problem with either one of my own. http://www.haydenauto.com/upload/Hay...il-coolers.pdf

 

Oh man that is gonna make it much more of a PITA, that connection down there looks much more... difficult to get to!

Also, checked under the cap... results are "meh?" everything still has a light coating of brown with shiny bits showing here and there on the trans cooler through the radiator cap, oddly enough they didn't seem to fully fill it though, no coolant visible under the cap, going to fill it today, all in all... not impressed with the coolant flush, in general, Dexcool is the devil.

What are the hard lines that go into the drivers side of the radiator BTW? Seems odd to bring something in on the HOT side!?

 

The lines on the left side are for the engine oil cooler. The engine oil cooler is similar to the transmission cooler... they are each mounted in a radiator side tank. The engine coolant flow in the radiator is horizontal. Hot coolant from the engine goes in the radiator through the upper hose. As it falls, it cools, and is sent back to the engine through the lower hose. The oil cooler and trans cooler are simply coils of tubing submerged in engine coolant. It's an el cheapo way of doing it, and not very efficient. Hot at the top, cool at the bottom. You can see the trans cooler when you remove the radiator cap. If you leave the OEM trans cooler connected, and install the add-on cooler in the lower line, you won't get the full benefit of the add-on cooler. The OEM cooler will actually heat the fluid to a higher temperature than if you eliminate it and use only the add-on cooler... defeats the purpose of the add-on cooler I monitored the TFT sensor, (transmission fluid temperature) on a 600 mile trip, before and after installing the cooler. With 75F ambient, using just the OEM cooler, TFT runs ~180F. Using just the add-on cooler, TFT runs ~135F. I would imagine that using both coolers in series, TFT would be ~160F ...just a guess though, never checked it.

 

I am suddenly keenly interested in if the TFT reports over OBD-II, or just stops at reporting to the PCM?

If it doesn't, how did you tie into it?

Also!

Here's what I see under the cap after the flush now.



Flash makes the orange fluid look like rusty water, but, its not, its pretty 'OK' I guess.



Meh? Eh? OK? I've never had a vehicle with Dexcool, but I've had quite a few with 10-20+ year old green factory fills and shiny perfect cooling systems when checked, so this is a new 'problem' for me and I'm not sure if I'm just overreacting?

 

Streaming live data from the TFT is viewed with a scan tool capable of accessing the transmission. The entry level scan tools can't access it. BTW, you can see the trans cooler in your image.

The main difference with ethylene glycol, (green) and Dexcool, (orange) is ethylene glycol does not protect aluminum against corrosion, (Dexcool does). It is also extremely abrasive to help "scrub" the surfaces in the cooling system, (Dexcool is nonabrasive). Older vehicles had very little, if any, aluminum so ethylene glycol worked fine. Over time it breaks down and needs to be flushed every year. Newer vehicles use aluminum for the radiator core, heater core and lower intake manifold. Dexcool loses its ability to protect the aluminum so it needs to be flushed every 3 years or 36K miles. If it is neglected, the aluminum components will corrode, guaranteed. It will cause radiator leaks, heater core leaks and lower intake manifold gaskets to leak due to the corrosion eating away at the manifold around the coolant ports. When that happens, the gasket can no longer seal the port, the gasket deteriorates, and it leaks, (very common on 4.3's). Using ethylene glycol in a vehicle with aluminum cooling system components will accelerate the corrosion process. The water pump seal has been redesigned in vehicles using Dexcool as well. The abrasive in ethylene glycol will destroy the seal. If Dexcool and ethylene glycol are mixed, the chemical reaction will turn the coolant to a brown mud... very time consuming and expensive to clean it out.

 

you obviously have the internet, just look for it on u tube. I have an 04 identical to yours and love it. am going to swap the 4.3 with a 5.3 ls. Good luck on your journey!