It is a well documented FACT that many vehicles benefit from an after-market transmission cooler.

Look at RV and 4x4 forums, not to mention special application vehicles such as Forrest service, ambulance, law enforcement, etc, etc...

Most of our vehicles are high mileage, the thermal load rises from stacked wear factors, and in some cases have exceeded any reasonable factory cooling capacity.

Many owners of RV, 4x4, and special application vehicles have learned why a separate transmission oil cooler is needed the hard way.
transmission oil cooler - Google Search
Transmission Temperature Gauge



For durability.
Removing the thermal load of the transmission from the engine cooling system is a win - win upgrade...
Your source for RV, heavy duty off-road and overdrive transmissions



.

dedicated transmission cooler in 1995 E300D

Buying and Installing a Transmission Cooler W123

Buying and Installing a Transmission Cooler W123

Transmission Cooler


.

I like the idea of an external cooler for my 95 E300, I'm sure the transmission would benefit quite a bit in my application as I drive through the mountains regularly in the dog days of summer. I'm hoping he'll be able to rig something up in that thread, or at least figure out a part number for the Mercedes unit. I am not really worried about my engine temps as I have to try really hard to exceed 100c, if I even can that is, but a cooler trans should help improve its life-span. Still, I wonder what my average trans temps are in stop-and-go and mountain driving in the summer, I imagine it can't be too far from 200*...or more.

I'm thinking anybody who drives mountains in the summer in AZ, or CA in a TD or SDL with the 603 would certainly benefit from an external plate style (like the oil cooler) transmission cooler. as a matter of fact, installing one in the same location as the oil cooler, and adding a thermostatically controlled fan would be an interesting project. heck, I bet the 617 would enjoy better life of the transmission with this upgrade...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

1) How so? The lower temperature 'stat buys time. That's all it can do. The cooling system has a fixed capability of dumping BTU's. That capability goes up with engine temperature and, the higher engine temperatures make the driver uncomfortable.

I stand by my earlier comments regarding the inability to find a single member who overheated an OM603 with a functioning water pump.


2) They offer the lower temperature 'stat to buy time. Typically, the driver is not going to be climbing a hill for 30 minutes or more. Therefore, if the engine starts at a lower temperature, there is more time available before the engine reaches 110°C., the point at which the driver should be slowing the vehicle and/or dumping the air conditioning.

Hey guys thanks for the replies. You've helped me understand that what works in one part of the country & in different seasons may not work so well in other geographic climates.

For example here in Southern California I never really have to take the below freezing (or colder) type precautions others have while operating in the north and north east.

Similarly out in the summer Desert South West where afternoon temperatures soar into the stratosphere, night temps never drop below 100*F, < ½ hour hills turn into very, very long grades, dash exterior temps gauges read 125+ at asphalt intersection lights, and travel runs at 75mph+for hours on end, a different set of rules apply.

I’m going to take a couple of extra steps to keep things cooler. To avoid critical review I think I’ll call them “soft mods” where in combination should help. For example window tinting should minimize full blast A/C demand by keeping the interior parts cooler. Some very smart folks in AZ will tell‘ya “it helps the A/C”. Another soft mod used to help the A/C is to hard wire the electric cooling fan “on” just because it works and a fair trade off if ya got to buy a new fan now and again. Mine has been hard wired for ages. Additionally, going with a radiator dedicated to the motor and move the trans cooling job over to its own cooler (like some other MB's); put the MB tropical climate thermostat in for the season, and maybe go with a fan other than the stock metal 9 blade...who knows maybe remove the high milage badges to reduce drag...kidding.

Thanks again...rob

__________________

1986 300SDL 440,xxx

Hey it may not help cool your engine, but they definitely help make the car cool.

Do keep this thread updated if you do install an external trans cooler, I'm sure everyone would love to see the pics and results.