MagikDraggin

Ok, so if I do bypass the tranny cooler in the radiator and use only an external cooler.....and winter comes where it gets really cold, what happens to the tranny with the cold fluid?

I mean, it's going to be cold anyway while sitting overnight, isn't it?

So it takes a little longer to heat up.....what are the major issues here that I should be concerned about, if any?....other than maybe eventually getting the fluid hot enough to burn off any condensation?

Dirty Howie

I think your question will get more action and may already be answered here:

http://forums.corvetteforum.com/show....php?t=1436233

If you are in a cold climate you can get a cooler with a fan which is thermally operated. Or you can cover it when its cold.

Most of us that are bypassing or considering bypassing are generating way above normal temps


DH

hotwheels57

A simple vinyl "bra" over the cooler will reduce the cooling effect. There are also thermostat valves...I think B&M RACING sells them for their stacked plated coolers.

yankeevetteconvert

[QUOTE=MagikDraggin]Ok, so if I do bypass the tranny cooler in the radiator and use only an external cooler.....and winter comes where it gets really cold, what happens to the tranny with the cold fluid?

I mean, it's going to be cold anyway while sitting overnight, isn't it?

So it takes a little longer to heat up.....what are the major issues here that I should be concerned about, if any?....other than maybe eventually getting the fluid hot enough to burn off any condensation?[/QUOT

I run this setup on my 02 vert. I put 50k on my trans. with no problems. It saw plenty of cold weather here in MI.I just put in a RPM level 4 trans. because I plan on running a little more power in the future and they had a great sale going on last month(free install). My old trans saw plenty of track time(1/4 only) and was running great when I replaced it.I would not worry about the cold weather.

MagikDraggin

Honestly, that's the way I see it.

No matter if you run the coolant through the radiator or bypass the radiator altogether, on a really ccccold morning where its below freezing, that's going to be the temperature of the tranny fluid anway, so what's the big deal about having the radiator "preheat" the tranny fluid?

That was the intent of the original question. Why does the tranny fluid "need" to be preheated? And what happens to it if it isn't preheated?

There's obviously something I'm missing here.

16Again

I don't know how much tranny fluid thickens up when the temps drop, that might be the reason for warming it. That said, I have always been told COOLER is better. HEAT is the enemy of your transmission.

MagikDraggin

Not being multi-viscosity, like our Mobile 1 motor oil is, I don't doubt it gets "thicker" when it's cold.

And when the Vette is first started up and driven off, after sitting all night at 15°F, the tranny does seem to function just fine, with that "thick" fluid. At least mine does.

According to some of the posts I've been reading here, the tranny fluid seems to heat right up just fine to well over 100°F in no time at all, with the radiator bypassed.

I have no reason to suspect it will not do the same in the colder winter climates....especially with a high-stall converter generating much of that heat by way of increased slippage/friction.

So far, I've not seem any comments that would suggest that there would be a problem with bypassing the radiator, so next chance I have, that's just what I'm gonna do.

Thanks for all the good input so far.

Dirty Howie

According to one of the top tranny builders you want at least 100*

The coolant is the fluid that heats up FIRST so it will take the chill off the tranny fluid

This cold temperature concern is another reason to support the use of synthetic ATF.

I will be bypassing the radiator and swithching to Amsoil ATF


DH

MagikDraggin

No disrespect, but this is like pulling teeth here, trying to get some kind of straight answer as to just what this "temperature concern" actually is and how it manifests itself.

The vette runs and operates just fine until the tranny temps finally get up to 100°F. So what happens if the tranny temps never get to 100°F?

It starts off cold, it runs X number of miles cold the way it is now. Just what IS this mysterious problem that everyone is talking about but never actually spelling out?

Dirty Howie

Actually as a DDS it would be much easier for me to pull your teeth than to explain this to you

But I will do my best. There is a cummulative affect on certain parts which lead to an ultimate failure. You will not see or necessarily even feel this happening. Its like when my tranny gave out. It didn't happen at the track when the temps were 260 and the CEL came on....it was months later.

So I assume just as in the engine there is a sweet spot for temps to prolong engine life.....too cold or too hot causes problems. Same for the tranny. But for the exact reason.....impact on clutches, seals etc. I don't really know. But when the experts say keep it over 100 I beleive them and obviously its not hard to get temps over 100 so the issue seems mute to me


DH

MagikDraggin

With what teeth I still have left, that's good enough for me. I agree with your final assessment as well, that it doesn't take long for the tranny temps to get up to and over 100 degs, winter OR summer. Tnx for the response and explanation.

Vette_Fan

With that in mind now - This cold temp thing may bother ppl who live in the colder climate. But for ppl like us in CA - SF bay area, does this apply to us also? I mean if we do a radiator bypass, in the winter, will there be a problem. It does get quite cold here, but nothing like snow or freezing? Just wondering...

davekp78

Another related issue: My stock '01 A4 won't lock up until the collant warms up to around 142 degrees. Maybe this is to overcome any issues with too cool ATF?

yankeevetteconvert

Read my post above. 50k on trans.with no problems.Plenty of cold winter miles.As stated in other post the fluid does warm up on its own when its unlocked.