Re: Transmission Temperature Gauage
I don't own a Sprinter, but I do own a PW Lexor which is built on the Chevy Express chassis. I tow regularly, usually a 6X12 V nose with a motorcycle (and what won't "fit" in the "B") and made some mods before towing.
I've done three things.
1. I added an ATF guage to the "A" pillar. The "sender" is mounted at the exit line from the tranny to the ATF cooler in front of the radiator. I also added - to the same pillar - an oil temperature gauge, since neither Chevy, nor my ScanGauge II, report that info. With the installation on the "A" pillar, it is real easy to keep an eye on the temps.
2. I replaced the "factory" tranny pan with a "finned" larger aluminum pan. It allows me to increase the ATF capacity by three quarts.
3. I added an aux ATF cooler, with thermostatically controlled aux electric fan, in front of the conventional ATF cooler.
On flat ground, with outside temps around 90 degrees, my ATF fluid is about 165 to 170 degrees. When I've been climbing, while towing, the ATF temp will occasionally approach 200 degrees.
As I understand it, as long as I stay below about 210 degrees, I'm not hurting my tranny - and that's my objective.
I do realize that others may well think a somewhat higher ATF temp is "OK", but, at several thousand bucks a pop to replace a tranny, I'd much rather be safe than sorry.