Originally Posted by TryNkeepUp

So in trying to solve my "too hot" trans temps during the summer, I added a B & M Transmission cooler to my 99 A4. Worked like a charm, but now with these colder temps in the northeast, it's a chore to get the transmission up to 120 some days.....highest temp I've seen since the ambients dropped below 70 is 140 on the trans. So my question is.......how cold is TOO COLD for the transmission to be running? TIA!!

Originally Posted by lucky131969

Just curious....what cold weather transmission temps did you observe before installing the trans cooler?

Originally Posted by Dave Sweatt

How did you plumb in the 2nd cooler? Best practise is to run through the B&M 1st, then from the exit of it to the inlet of the one in the radiator. Acts as kind of a re-warmer in cold weather.

Originally Posted by Dave Sweatt

ahhh-soooo, just my WAG anyway.
Good luck!

Originally Posted by aleadfoot

You dont need to worry about the cold temp but start thinking about tranny rebuild next year. High temps like 240 and the power you are making will cause that A4 to need a spa treatment Better to know it is coming and be prepared. Watching the A4 temps is good to do. Hot(+220) is not good. When did you last change the A4 fluid ? How many miles and burnouts on the trans..Best of Luck

Originally Posted by 427435

It's grapes and grapefruit, but I have a transmission temperature gauge on my MH (V10 Ford and 4 speed auto). It has a good size cooler but it's also over 25,000 lbs GCVW. Temps get to 200-210 climbing the Rockies, but run as low as 140 on the flat interstate.

You're probably OK with temps under 160, but covering (or partially covering) the transmission oil cooler wouldn't be a bad idea. Less issues with condensed water in the fluid that way. Even though my MH runs under 150 at times, most days it will get to 180-190 and keep condensation to a minimum.

Originally Posted by Alex1217

For what it's worth, I've seen 120-140 tranny temps this winter, I also have a tranny cooler mounted up front. Don't forget, transmission fluid is designed to work in temperatures as low as -5 degrees and still keep it's viscosity. The viscosity of the fluid or lack thereof is what can kill the tranny, since at 230+, the oil begins to breakdown, you risk damaging your tranny. On the other end of the spectrum, although you're not at your sweetspot, tranny temps of 130 shouldn't do any prolonged damage as long as you don't floor it as soon as you leave the driveway.

The 4L60E trannies were tested in subzero temps by GM for prolonged periods of time. They were designed to handle cold temps.

Originally Posted by TryNkeepUp

Now why didn't I just call you in the first place

Originally Posted by amsoil

Subject: How Cold Temperatures Affect Automatic Transmission Efficiencies

http://www.performanceoiltechnology....ing_fleets.htm

OBJECTIVE:
Demonstrate that AMSOIL Synthetic Universal ATF has excellent low temperature properties, including low Brookfield Viscosity and pour point, and provides higher automatic transmission efficiencies at low temperatures than conventional automatic transmission fluid.

ISSUE:
The use of conventional automatic transmission fluid at low temperatures means slow transmission shifting, sluggish operation and frustration.

TECHNICAL DISCUSSION:
Automatic transmission fluid is a vital component in an automatic transmission. Fiber plates contact metal plates, bearings contact bearing races, gears contact gears and automatic transmission fluid comes in contact and lubricates them all. Transmission fluid viscosity has a tremendous effect on the mechanical efficiency of an automatic transmission. During transfer of power in the transmission, over 40 percent of total energy losses are due to the transmission pumping automatic transmission fluid to the working components of the transmission. Tests (Reference 1) relating to torque losses associated with pumping automatic transmission fluid at different temperatures have shown that a temperature increase of 150°F can increase the mechanical efficiency of an automatic transmission by as much as 37.5 percent. This means increases in mechanical efficiencies are directly caused by thinner oil (lower viscosity). When ambient temperatures drop, the fluid gets thicker and transmission efficiencies decrease, greatly reducing effective useful power and efficiency of the transmission.

This efficiency decrease in cold temperatures is often referred to as sluggish operation, and it demands more energy from the engine to actuate all the parts that come into contact with the automatic transmission fluid. Synthetic oils that are not affected by temperature reductions as much as conventional oils have better low temperature pumpability and mechanical efficiency. Improved efficiency provides better fuel economy.

AMSOIL Synthetic Universal Automatic Transmission Fluid has a lower pour point and is pumpable at much lower temperatures than conventional automatic transmission fluids, as demonstrated by the Brookfield Viscosity Test. AMSOIL Synthetic Universal ATF is capable of providing greater transmission efficiencies and better fuel economy at low temperatures than conventional automatic transmission fluids.

RECOMMENDATION:
In order to obtain maximum cold temperature benefits, thoroughly drain and flush conventional automatic transmission fluid from the transmission and replace with AMSOIL Synthetic Universal Automatic Transmission Fluid (ATF).

Originally Posted by Wicked Weasel @ ECS

the best bet is that your tranny temps should be around your normal operating engine temps.

here is more info from Amsoil

Originally Posted by GeorgeZNJ

I don't have any technical advice to offer, buy I'll come over and warm you up anytime Deb.