Is this transmission cooling setup normal/acceptable

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alpinecrick

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Is it reasonable to assume any oil thermostat's flow rate (open or closed) can be judged by it's connection sizes?
ATF coolers are rare in the UK but engine ones are easier sourced. An engine one with 3/8'' connections - suitable for a 4L80E with 3/8'' OD hard lines?

Good question. Are some manfacturers simply using the same thermostat with larger nipples or are the internal passsage sizes different.......

With a 4L60E size trans the 3/8 lines are apparently sufficient flow so I wouldn't worry. Just don't use a trans cooler for a engine oil cooler............
 

alpinecrick

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All this hand wringing about transfluid warming up when heat is what destroys many,if not most transmissions. Noting will warm up the trans faster than a trans fluid thermostat,and without the risk of coolant contamination of trans fluid... Which is always a possibility when using the cooler built into the vehicle's radiator of which I'm not a fan.

That's like saying keeping the engine coolant under a 100 degrees is good for the engine. All the systems are designed to operate within a temp range.

Cold hydraulic fluid puts a lot of pressure on pumps, valves, seals, etc.

Warning up the trans fluid is a good thing.

I know it happens but I've yet to see the heat exchanger in the radiator on one of these trucks fail. The seam in the plastic tank or wranging on the radiator hose outlet/inlet while trying to remove the hose is what usually fails first.
 

HotWheelsBurban

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That's like saying keeping the engine coolant under a 100 degrees is good for the engine. All the systems are designed to operate within a temp range.

Cold hydraulic fluid puts a lot of pressure on pumps, valves, seals, etc.

Warning up the trans fluid is a good thing.

I know it happens but I've yet to see the heat exchanger in the radiator on one of these trucks fail. The seam in the plastic tank or wranging on the radiator hose outlet/inlet while trying to remove the hose is what usually fails first.
Granted, it's not a Chevy, but it's put together similarly to the radiator system the GM LS motors have. The internal radiator transmission fluid warmer is leaking on my 01 F150. The modular Ford engine uses a pressurized fill tank ( degas bottle is their term) with the " radiator " cap on it. Transmission fluid was disappearing and no leaks were detected under the truck. It's a 4x4 and lifted a little so I can get under it w/o a jack. I was changing out a loose clamp on the bottom of the tank and discovered the coolant and transmission fluid have been mixed.
This truck was on a ranch for the last few years, and not driven much. Then,a month ago, the guy I got it from drove it from south Texas to Houston (~200 miles)(full throttle probably, that's the way he drives) without checking the fluids. His mom had just had the truck "serviced" and state inspection done. Is it possible that it could have been seeping for a while, and the problem didn't get bad until the truck was driven more in Houston traffic? The radiator is built like the GM ones, plastic tanks and aluminum core.
Transmission fluid and orange coolant make chocolate milk just like with motor oil.
 

Pinger

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Good question. Are some manfacturers simply using the same thermostat with larger nipples or are the internal passsage sizes different.......

With a 4L60E size trans the 3/8 lines are apparently sufficient flow so I wouldn't worry. Just don't use a trans cooler for a engine oil cooler............

On the basis that trans oil flow is unlikely to be less than engine oil flow and, the pipe sizes should be an indication of what can be handled internally - I've just ordered a cooler. Supposedly an engine one but can't see why it wont work with my trans. Barb fittings so an easy cut hoses and fit job. Fed up of my trans being so lumpy when cold - I'm hoping a change of ATF will help that also. Cooler being stone cold the other day after 15-20 miles was the clincher. I'll probably fit the cooler first - see what difference it makes on its own.

So, time to start researching ATF drain and re-fill. Am I right in thinking that I can drain the TC by having a cooler line free and run the engine until fluid stops coming out?
 

Pinger

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Granted, it's not a Chevy, but it's put together similarly to the radiator system the GM LS motors have. The internal radiator transmission fluid warmer is leaking on my 01 F150. The modular Ford engine uses a pressurized fill tank ( degas bottle is their term) with the " radiator " cap on it. Transmission fluid was disappearing and no leaks were detected under the truck. It's a 4x4 and lifted a little so I can get under it w/o a jack. I was changing out a loose clamp on the bottom of the tank and discovered the coolant and transmission fluid have been mixed.
.

That's what makes that failure so lethal - no warning puddles underneath.
 

alpinecrick

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Granted, it's not a Chevy, but it's put together similarly to the radiator system the GM LS motors have. The internal radiator transmission fluid warmer is leaking on my 01 F150. The modular Ford engine uses a pressurized fill tank ( degas bottle is their term) with the " radiator " cap on it. Transmission fluid was disappearing and no leaks were detected under the truck. It's a 4x4 and lifted a little so I can get under it w/o a jack. I was changing out a loose clamp on the bottom of the tank and discovered the coolant and transmission fluid have been mixed.
This truck was on a ranch for the last few years, and not driven much. Then,a month ago, the guy I got it from drove it from south Texas to Houston (~200 miles)(full throttle probably, that's the way he drives) without checking the fluids. His mom had just had the truck "serviced" and state inspection done. Is it possible that it could have been seeping for a while, and the problem didn't get bad until the truck was driven more in Houston traffic? The radiator is built like the GM ones, plastic tanks and aluminum core.
Transmission fluid and orange coolant make chocolate milk just like with motor oil.

Keeping the fluids clean also makes the parts last longer.....dirty coolant, dirty ATF probably contribute to earlier failure of parts.
 

Pinger

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How much does the radiator really warm up the fluid before the aux.cooler in front cools it back down?

Not at all until the coolant thermostat has opened.
Until then, the ATF is warming stationary water in the coolant radiator. It only makes sense to tie coolant and ATF together if the coolant isn't inhibited by its own thermostat.
When I was considering a liquid to liquid exchanger, plumbing it into the heater circuit was my plan. Glad I don't have to now - I already have an LPG reducer there and maybe another one as well shortly. Anything more in that circuit and I'd be freezing in the winter.
 

alpinecrick

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How much does the radiator really warm up the fluid before the aux.cooler in front cools it back down?

As I have mentioned, the stacked plate factory cooler has a passive bypass feature in the external cooler that sends the majority of the cold fluid back to the trans without passing through the entire cooler. Once the fluid has warmed and the viscosity has changed, the majority of the warm/hot fluid flows through the cooler. Consequently, the TQ, pump, etc, sitting there spinning even when in Park is making heat.

The stacked plate design is the only cooler I'm aware of that is capable of the passive bypass. Plate & fin and tube & fin need a separate, mechanical bypass/thermostat.
 

alpinecrick

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Not at all until the coolant thermostat has opened.
Until then, the ATF is warming stationary water in the coolant radiator. It only makes sense to tie coolant and ATF together if the coolant isn't inhibited by its own thermostat.
When I was considering a liquid to liquid exchanger, plumbing it into the heater circuit was my plan. Glad I don't have to now - I already have an LPG reducer there and maybe another one as well shortly. Anything more in that circuit and I'd be freezing in the winter.

Pinger,
Keep in mind most thermostats have a "steam hole" that does allow some coolant flow. plus whatever coolant gets around the not-perfect valve.
 
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