Is an external tranny cooler needed

[John Griswold]

Ok, going to be running the 4R70W tranny with an Explorer 5.0. The radiator is a Ron Davis radiator from Wild Horses. The radiator has the inlet and outlet reversed for the Explorer swap. The trans cooler is on the driver side so it is on the cool side of the radiator. Should the radiator trans cooler be enough cooling for the 4R70W or is an additional cooler needed. I am set to plumb the trans lines to the radiator with 6an fittings but I don't see an easy way to get around to the front of the radiator and back for an added cooler.
The truck will just be driven around town with maybe some highway driving. The tires are only 31" x 10.5".
So is the extra cooler needed?
How effective are the remote coolers with their own little fan?
Thanks

 

[nickgp]

You will be fine with the cooler in the rad

 

[SteveL]

What about a frame rail cooler?

 

[John Griswold]

I've been trying to read up on cooler types and have not found anything saying how well the aluminum heat sink frame rail types effectively cool. Seems like in front of the radiator with a stacked plate type cooler is most efficient. Have not really found anything comparing the ones with their own fan to other types.

 

[Rustytruck]

For a stock engine driven on the street an in the radiator cooler should be enough for reasonable tranny life. If you do anything with extra stress it would be wise to upgrade your tranny cooler. It is one of the best modifications you can do.

 

[Rusty_S85]

your best bet is to use a temp gauge in your transmission pan and if temps start to go over 180 - 190 degrees then you should consider adding an auxiliary cooler after your radiator cooler.

Its what I will be doing if I need the extra cooling but I don't think I will.

 

[sanndmann3]

Can't beat a fluid to water cooler, I bet you will be fine just the way you are. I would try it out and add a stacked plate cooler if necessary later on.

 

[garberz]

I’d run an auxiliary cooler with that. Even from the factory, Ford uses the heat exchanger, and a good sized, stacked plate trans. cooler.

Mark

 

[Broncobowsher]

All applications of the 4R70W I can think of use 2 coolers. The 4R70W has a looser torque convertor than a C4, this make the convertor run hotter. So what works for a C4 isn't the same as what a 4R70W needs. This applies for stop and go driving.

The good thing about the 4R70W is the convertor lock up. At cruising speed the convertor will lock up. Locked up the 4R70W will run cooler. But only when the convertor is locked will it run cooler.

 

[Rustytruck]

You really need to make sure axle gearing stays in sync with tire size increases. Get too far out of snyc and you cook a tranny.

 

[blubuckaroo]

I normally go with the factory type heat exchanger. But, in your case, you've obviously already spent a lot of money, you would be well advised to install a good size air cooler.
The reason is, with all the $ you've spent, you probably expect it to last a long time.
But I've got to add this...
Heat isn't what kills your tranny. It's fluid that's worn out because of heat.
Replace your fluid at reasonable intervals. You'll avoid all this.

 

[John Griswold]

Thanks for all the input. I think I will take another look at adding a stacked plate cooler. It certainly won't hurt.

 

[pbwcr]

John,
Several of us have needed external cooler. However do not assume you need more than the stock radiator trans cooler setup. Your decision will be based on a quality trans cooler gauge readings where you usually drive. Put the gauge sender in the trans pan.