Additional Trans Cooler.

[03Merc]

What are the pros n cons of adding another transmission cooler in-line with the factory one?


2004 MM Build #1618 & DTR #537

[ctrlraven]

Pros - cooler trans temps and adds a few more quarts of fluid to the total capacity.

Cons - Living in FL you wouldn't have to worry about it keeping the temps too cool and it costs a few bucks more when replacing all of the fluid.

I've had mine installed for like 5 years now, have never seen my trans temp get higher than 174 and that was in stop-n-go traffic with the ac on and above 95 degrees ambient air temp.

[fastblackmerc]

Cooler fluid = longer transmission life.

[juno]

No cons. Do it.

[ledahettice]

you want a giant tranny cooler,grab a AC condenser off of a smaller car and use that,works so good even mudbog trucks will not get hot!

[RF Overlord]

No cons. Do it.The only time it would be a con would be in dead of winter in northern states where the factory thermostatic bypass would normally allow the fluid to warm up quicker, only to have the aux cooler cool it right back down again. In Florida, there are no cons.

[lifespeed]

Our factory transmission coolers are decent-sized. When I went to have a large stacked-plate cooler installed the mechanic reminded me of this, questioning the need for a second cooler.

I went ahead and put in the largest stacked-plate cooler I could fit, with proper aluminum brackets instead of the silly plastic zip-ties through the radiator. Transmission temps never get over 170F even towing a trailer up a hill, which was the reason I put it in there. Typical temps are in the 140F to 150F range. The transmission still works great at 130K miles and the fluid is cherry red.

If you aren't planning on towing I would first get a quality OBDII Bluetooth dongle and the Torque app for your phone and monitor transmission temperatures. It is not clear to me a second cooler is required for ordinary driving when not towing a heavy load.

[03Merc]

Our factory transmission coolers are decent-sized. When I went to have a large stacked-plate cooler installed the mechanic reminded me of this, questioning the need for a second cooler.

I went ahead and put in the largest stacked-plate cooler I could fit, with proper aluminum brackets instead of the silly plastic zip-ties through the radiator. Transmission temps never get over 170F even towing a trailer up a hill, which was the reason I put it in there. Typical temps are in the 140F to 150F range. The transmission still works great at 130K miles and the fluid is cherry red.

If you aren't planning on towing I would first get a quality OBDII Bluetooth dongle and the Torque app for your phone and monitor transmission temperatures. It is not clear to me a second cooler is required for ordinary driving when not towing a heavy load.


I have the App Dash Command but it doesn't monitor Trans temp. Is there an app that does?


2004 MM Build #1618 & DTR #537

[03Merc]

Cooler fluid = longer transmission life.


Go from the trans to the new cooler first then to the original back to the trans?


2004 MM Build #1618 & DTR #537

[lifespeed]

I have the App Dash Command but it doesn't monitor Trans temp. Is there an app that does?


If you aren't planning on towing I would first get a quality OBDII Bluetooth dongle and the Torque app for your phone and monitor transmission temperatures. It is not clear to me a second cooler is required for ordinary driving when not towing a heavy load.
_____________________

[lifespeed]

Go from the trans to the new cooler first then to the original back to the trans?

Factory cooler first, as it has a quasi-thermostatic bypass for cold temps.

[03Merc]

Factory cooler first, as it has a quasi-thermostatic bypass for cold temps.


But if I run thru the new one first that ensures it will always be working. The factory one only turns on when it needs to correct?


2004 MM Build #1618 & DTR #537

[03Merc]

Pros - cooler trans temps and adds a few more quarts of fluid to the total capacity.

Cons - Living in FL you wouldn't have to worry about it keeping the temps too cool and it costs a few bucks more when replacing all of the fluid.

I've had mine installed for like 5 years now, have never seen my trans temp get higher than 174 and that was in stop-n-go traffic with the ac on and above 95 degrees ambient air temp.


You went from the new one to the factory or thru the factory one first?


2004 MM Build #1618 & DTR #537

[RF Overlord]

But if I run thru the new one first that ensures it will always be working. The factory one only turns on when it needs to correct?
You're sort-of correct.

The factory cooler has a built-in thermostatically-controlled bypass. This means the cooler is bypassed when ATF temp is low. As the fluid warms up, the cooler is brought into the picture. Installing the aux cooler before the factory cooler just means it will take longer for the factory cooler's bypass to open.

[03Merc]

You're sort-of correct.



The factory cooler has a built-in thermostatically-controlled bypass. This means the cooler is bypassed when ATF temp is low and as it warms up, the cooler is brought into the picture. Installing the aux cooler before the factory cooler just means it will take longer for the factory cooler's bypass to open.


Exactly what I was thinking, I hooked it all up My way and it seems to be fine. I don't have a gauge so I don't know what it was originally temp wise but down here in South Florida I thought it was necessary to add another cooler. I will get a gauge hooked up next. Any suggestions on doing that?

http://images.tapatalk-cdn.com/15/08/09/71b84ceed99c80ee0ddfd9ab945a48 0b.jpg


2004 MM Build #1618 & DTR #537

[lifespeed]

Over-cooling the transmission fluid is not helpful. It needs to squeeze out from between the clutch plates during shifts, hence the factory design to allow some basic control over temperature. And aftermarket true thermostats are available as cooler accessories, but they are expensive.

For you in Florida it will make no difference. But for general use I wouldn't advocate defeating the factory cooler bypass.

To complicate things further, you may have a temperature bypass in your aftermarket cooler. It is basically just a viscosity-based bypass path, primitive but effective.

[RF Overlord]

I will get a gauge hooked up next. Any suggestions on doing that?I used this (http://www.autometer.com/temperature-manifold-adapter-for-5-16-od-tubing.html).

You can also drill & tap the pan, but putting the manifold in the line from the transmission to the cooler will give more accurate readings.

[justbob]

There is a test port on the drivers side front that I use. Your temps will read a little higher do to it reading the temps right after the converter.


Builder Of Badassery

[03Merc]

I went pretty hard on the car today with a lot of highway driving in 95+ degree weather. It never went over 197 degrees.


2004 MM Build #1618 & DTR #537