Heating the transmission with engine coolant

[Baltothewolf]

Originally Posted by aerohead

At automotive refinishing supply houses they sell viscosimeters which could be used in testing.
Samples of gear oil,in baby food jars can be placed in the refrigerator and freezer,and also heated in an electric double-boiler.
With a good cooking thermometer you can test the pour-point viscosity of the oil at different temps and get a feel for what heating will do.
One thing we know,is that whatever equilibrium temperature we achieve in the winter, will be nothing compared to a summer day at Furnace Creek,Death Valley,California,where gear oil would be plenty happy.
At one point,VW as going to use the Schacht',eutechtic (sp?) salt thermal storage system for warm cold-starts.It's a very sound engineering concept.

It gets 115 here in the High Desert(Apple Valley). Ahh I miss those days... Now it's freaking cold, dropped into the 50's last night wtf desert! Give me my summer back!

[Cobb]

Ill trade with you, Ill take your 50 degrees 24x7 and give you 90 degrees and 100% humidity.

Originally Posted by Baltothewolf

It gets 115 here in the High Desert(Apple Valley). Ahh I miss those days... Now it's freaking cold, dropped into the 50's last night wtf desert! Give me my summer back!

[Gasoline Fumes]

I think the ideal way to go is with a pump and external heat exchanger. Trans/diff pumps exist, but they aren't cheap. There must be a cheaper alternative out there.
Pumps - Mocal Differential Cooler Pump
http://www.summitracing.com/search/p...l-cooler-pumps

Combine a pump with a plate heat exchanger.
Plate heat exchanger - Wikipedia, the free encyclopedia

You could also add a filter. And even use the pump to change the fluid!


What about using a fluid thinner than recommended and just adding a trans cooler to keep viscosity up on long trips and/or hot weather? Same result of ideal and consistent viscosity without the warmup wait?

[darcane]

Originally Posted by Daox

I have no idea what my temps actually are. Throwing a sensor on the trans would definitely be step one. I found some info online from truck guys measuring trans temps, but it really wasn't all that useful. They didn't measure warm up times or anything like that, and they're mostly automatics which I assume heat up much faster and farther than a manual trans.

What about ambient air temps in winter? That should be the same as your oil temp when you first turn on the car in the morning.

[darcane]

Originally Posted by aerohead

At automotive refinishing supply houses they sell viscosimeters which could be used in testing.
Samples of gear oil,in baby food jars can be placed in the refrigerator and freezer,and also heated in an electric double-boiler.
With a good cooking thermometer you can test the pour-point viscosity of the oil at different temps and get a feel for what heating will do.
One thing we know,is that whatever equilibrium temperature we achieve in the winter, will be nothing compared to a summer day at Furnace Creek,Death Valley,California,where gear oil would be plenty happy.
At one point,VW as going to use the Schacht',eutechtic (sp?) salt thermal storage system for warm cold-starts.It's a very sound engineering concept.

One of my engineering lab experiments in college was doing just this. We left samples of a variety of oils (engine oil and gear lube, synthetic and conventional. I forget the viscosity ratings, but they were chosen to be representative of commonly used oils) outside overnight (-40 to -50 F) and measured their viscosities while gradually heating them.

The difference between synthetic and conventional oils was eye-opening. At extreme cold temps, the conventional oils were very thick: a spoon would stay standing up in the engine oil, the gear lube was too thick to measure and was more like tar than oil. Both synthetics were basically the same as they are at room temperature, but just more viscous.

While not quite as extreme, I assume Daox's winters get rather cold in Wisconsin. If so, synthetic oil should provide a large improvement.

[2000mc]

75w90 comparisions http://www.grattaoil.com/wh/A-Study-...Gear-Lubes.pdf

I saw there is also FE 75w90 but i don't think they're for transmissions

[Daox]

I definitely agree going to synthetic makes a big difference. I did this in my 97 Paseo I had been driving a few years ago. I did the trans oil change in the middle of winter and the difference was night and day when shifting. I couldn't get an actual mpg increase from it as A B A testing would be difficult though.

[oil pan 4]

Originally Posted by Gasoline Fumes

I think the ideal way to go is with a pump and external heat exchanger. Trans/diff pumps exist, but they aren't cheap. There must be a cheaper alternative out there.
Pumps - Mocal Differential Cooler Pump
http://www.summitracing.com/search/p...l-cooler-pumps

A standard chemical rated surflow diaphragm pump would likely work just as well.

[Daox]

Why would you want to use an additional electric pump (and thus another load on the engine), when you could just use the coolant pump that is already on the car?

Also, does anyone have any ideas on where I could repurpose (for $ reasons) or find a 12V solenoid valve that might work for this application?

[oil pan 4]

Any water rated solenoid would work.
Viton or buna rubber seals would be better.