Do I need a transmission cooler?

[SSDDBRONCO]

I’m in the process of swapping to a 4r70w transmission. After reading several threads on cooler lines I’m questioning if I need to run a transmission cooler for the 4r70w or if I can just run the cooler lines directly to my radiator the way the previous C4 trans was ran before? I’d rather not have to run a trans cooler but if it’s highly recommended then what cooler should I use?

Thanks

 

[sanndmann3]

what kind of driving do you partake in? The in radiator trans cooler is pretty efficient but may not be enough if you have a lead foot... stacked plate coolers are the most efficient.

 

[SSDDBRONCO]

what kind of driving do you partake in? The in radiator trans cooler is pretty efficient but may not be enough if you have a lead foot... stacked plate coolers are the most efficient.

Well most of my driving is highway/street and to get to easy/mild off road trials. I am running 35’s so that might be another factor too.

 

[gnpenning]

Are you running the stock 3.50 gears or planning a gear change?

 

[blubuckaroo]

What you mean is, do I need an additional tranny cooler?"
That little heat exchanger in the radiator shouldn't be small. It should be considered the main cooler. Heat transfer from liquid to liquid is always better than liquid to air.

Should you add a cooler?
Maybe. depending on your use.

Will an additional cooler hurt?
No.

 

[SSDDBRONCO]

Are you running the stock 3.50 gears or planning a gear change?

Upgraded to 4.88 gears

 

[Broncobowsher]

I tried an in radiator cooler only. On the road it still ran warm. Still needed a mid-sized oil to air cooler.

4R70W, 4.88, stock convertor, 33s, super hot AZ summer day, flat road with a lot of cruising.

The progression started with a monster super duty cooler. Blocked too much airflow, engine ran warmer than in the past. Took that cooler out and the engine ran cooler but the transmission was a lot hotter. Put a normal sized stacked plate cooler in, both were good. Your results may vary.

 

[SSDDBRONCO]

What you mean is, do I need an additional tranny cooler?"
That little heat exchanger in the radiator shouldn't be small. It should be considered the main cooler. Heat transfer from liquid to liquid is always better than liquid to air.

Should you add a cooler?
Maybe. depending on your use.

Will an additional cooler hurt?
No.

Yes that’s what I meant an additional tranny cooler. I read on other threads that people were using stacked plate coolers like sandman mentioned about and was wondering if I should even need to run one of those. I never had issues with my C4 but I’m not sure if the 4r70w require more cooling.

 

[SSDDBRONCO]

I tried an in radiator cooler only. On the road it still ran warm. Still needed a mid-sized oil to air cooler.

4R70W, 4.88, stock convertor, 33s, super hot AZ summer day, flat road with a lot of cruising.

The progression started with a monster super duty cooler. Blocked too much airflow, engine ran warmer than in the past. Took that cooler out and the engine ran cooler but the transmission was a lot hotter. Put a normal sized stacked plate cooler in, both were good. Your results may vary.

Thanks for that info. Do you happen to have a part number for the stacked plate cooler you are using or something similar to it?

 

[904Bronco]

Uhm... 4R70W has 3/8' cooling lines. C4 and factory Rads have 5/16" cooling lines, so you could be looking at a restriction... Just something else to think about.

I used a #HDA-689 Tranny cooler from Summit Racing with AN fittings

 

[jckkys]

I have run an additional trans cooler for my C4 and made the mistake of mounting it in front of the radiator. It made the engine run hotter. Something you don't want in 110 degree Az. heat.

 

[bronco loco]

What is an ideal temperature for the 4R70W? mine runs at about 170-172F.

 

[Broncobowsher]

What is an ideal temperature for the 4R70W? mine runs at about 170-172F.

That's good.

There is no exact perfect temperature. Anything in that range is good.

And someone will post an old internet picture with transmission fluid live vs. temperature. Which gives the illusion of exact data, but it is still just a range. Too cold is also an issue that most don't think about, but can be an issue. Most modern transmission (in the past ~10 years) actually have fluid heaters in them. The idea is put some coolant heat into the transmission to get it up to temperature. That way the convertor can run locked more to keep things more efficient.

 

[bronco loco]

Thank you. I do have transmision and a power steering cooler.

 

[pbwcr]

It is normal to cool a trans with the radiator without question.
I guess you should know what the trans temp without a cooler.
For starters hook up the trans to the radiator cooler. Then find a trans cooler gauge. A simple one that has the sensor epoxied to the trans pan with a gauge you can temporarily put on the passenger seat will be adequate to see what is going on. Drive where you think the load is the highest. Like up a long grade on a hot day. Then you can decide if more cooling is needed.
Choices for a temp gauge are numerous and found with a google search.
== ==

I’m in the process of swapping to a 4r70w transmission. After reading several threads on cooler lines I’m questioning if I need to run a transmission cooler for the 4r70w or if I can just run the cooler lines directly to my radiator the way the previous C4 trans was ran before? I’d rather not have to run a trans cooler but if it’s highly recommended then what cooler should I use?

Thanks