So we identified part of the problem with the ac in the elky as insufficient flow to the condensor. This Is caused by a massive trans cooler that Is almost the same size as the rafiator.
I was always told to stuff the biggest trans cooler I possibly could to make an automatic live longer and healthier. So that's the reason for the giant. Trans fluid only goes to this cooler. None goes through the radiator.
Its a stock tbi 350 and 700r4 from an 89 chevy truck. From the factory, the trans fluid was only cooled by the radiator.
The elky is used for light duty hauling, daily driven, some autocross and hooning. I live in north Carolina, and the truck gets parked when it gets to snowing. If it's just berkeleying cold, I'll still drive it if I need a truck.
Most it tows is a riding mower on a small wood utility trailer, thoughE36 M3boxes and a dolly aaren't out of the question.
So how much cooler do I actually need? How much do I want?
Ive got a smaller stacked plate cooler from an ambulance i can use if need be, or plumb it back to the radiator lime stock.
So, teach me please.
The factory radiator cooler should be fine for what you are doing. The other option is route through the radiator to dump most of the heat, then the external cooler. It might help the A/C some. That's how I usually plumb them and I've never noticed a loss of A/C capacity.
I have used Mocal coolers when it really mattered. I have always just called them and there tech dep has been helpful.
Toyman01 wrote:
The factory radiator cooler should be fine for what you are doing. The other option is route through the radiator to dump most of the heat, then the external cooler. It might help the A/C some. That's how I usually plumb them and I've never noticed a loss of A/C capacity.
I agree that the factory set up should be fine. Any reason it is not running through the radiator cooler?
A side discussion - I have always run my cooler circuit trans>Cooler>radiator>trans. The idea was that you did not want your trans mission to run too cold and the radiator after the cooler helped regulate that.
The setup you described is terrible for the trans (assuming no thermostat), too cold is almost worse than too hot, as water buildup will never cook off. Also increased drag from higher viscosity. Unless you are using a thermostat equipped cooler, it should always go trans out>aux cooler>radiator oil-water cooler>trans in, this way the ATF is always at coolant temp, which is about where it should be.
For your purposes, it sounds like the smallest of aux coolers is all you need, if any.
So, here's a question: what temp should fluid be at? I've always heard 230 is the limit, and 180 is just right. Is that correct?
Tom Suddard wrote:
So, here's a question: what temp should fluid be at? I've always heard 230 is the limit, and 180 is just right. Is that correct?
170-180F. Anytime you get above about 220F, every 10 degrees cuts life expectancy by half. But that is based on normal atf and the expectation of servicing the fluid every 40k-ish.
Trans shop I deal with ALWAYS deletes the cooler in the rad from the system and puts a larger cooler in frount of the rad. They told me it is to prevent trans damage from a motor over heat. In early explorers with the 4.0 the intake gasket would fail. This lowered the coolant level to the point that the trans cooler was exposed and not providing enough cooling for the trans but it would keep the motor cool. This would kill the trans in short order. It is also why explorers with the 5.0 got the reputation of having better transmissions when in fact it was really a problem with the motor not the trans on the 4.0 l motors.
Tom,
The temps noted above are what I was told. 170-180 deg operating temp. Anything over 200 is bad. Get to 220 and you are doing damage quickly.
With the advent of synthetic trans fluid a transmission may be able to survive a bit more heat but I have been told that modern transmissions having tight tolerances. The fluid may be able to take it and not gum up but the added heat may actually cause the metal to expand closing off the space where the fluid flows in the tighter tolerance of the modern trans. This is similar to why modern motors require 5-20 or even 0-20 motor oil.
The factory cooler should work just fine.
I towed my race car all over the NE with my KJ for 75K mile. In all kinds of weather.
No not all was towing.
So, since I used the factory cooler for a power steering cooler previously, how do I clean the residue out prior to running atf through it?
Now granted, probably overkill on the trans cooler but if you're satisfied with it and want to keep it, why not just swap locations and make sure the AC condenser is in ahead of the cooler and rad.
for what is worth.. my Disco comes with a separate cooler for the transmission stock. It is only about 6 inches high and runs the width of the radiator. I am pretty sure the disco is rated to tow more than an Elky
Dusterbd13 wrote:
So, since I used the factory cooler for a power steering cooler previously, how do I clean the residue out prior to running atf through it?
Do you know what vehicle it came from? Most PS systems use ATF.
Dusterbd13 wrote:
So, since I used the factory cooler for a power steering cooler previously, how do I clean the residue out prior to running atf through it?
PS fluid is close enough to ATF for it not be an issue, as long as it's clean in there you're good to go. If not there are products just for flushing out coolers and lines in cases where a transmission failed and filled them with junk.
wlkelley3 wrote:
Now granted, probably overkill on the trans cooler but if you're satisfied with it and want to keep it, why not just swap locations and make sure the AC condenser is in ahead of the cooler and rad.
that is a good point.. AC robs power and you need all the power you can get while towing.. so why not swap them around?
Over cooling is not good. The ATF needs to get hot, just like engine oil.
I actually on one truck I had thought of getting a roughly 12x12 inch cooler and mounting it up under the bed and putting a temp sensor on the input side and a 12 inch flat fan on top of it spaced off the bottom of the bed to get enough air flow. Then I would put some sort of grill or screening un frount of it for rock protection. Never got around to it and sold the truck.
In reply to Dusterbd13:
Think if the cost of an overhaul on your transmission, then the cost of a new cooler (the giant cooler I use on my trucks only costs $150.00 and it's the biggest one that Tru-Cool makes).
Don't re-use transmission coolers, too much potential for crap running through your trans.
As stated before, too cold fluid is more dangerous than 220* fluid. The best way is through rad to external cooler then back to the tran . Thats how factorys do it with towing package trucks, temp warms up as quickly as possibly but is slightly cooler than coolant temp, temp stays more consistent, ect.
Someone asked how to clean a cooler, DONT THROW ONE AWAY! Well unless you tosted a trans and want the insurance for an expensive new one. But autoparts stores sell trans cooler flush, a foaming aerosol with a hose that cleans it out real good. I can't remember the brand I used but its a smallish can (coke can size) about $10.
