Engine and tranmission cooling issues!

[bmblauvelt]

I have a 1977 Bronco Ranger with a modified 302 V8. To combat cooling issues with the overheating issues, I have done the following:

- installed an aluminum racing radiator, and removed the transmission lines from the radiator cooling load
- added a seperate transmission tube and fin type oil cooler welded on to the frame below the engine (I have done serious off roading, and the only damage came when I totaled a Pontiac GrandAm when I rear ended it - oops)
- added a copper marine transmission cooler inline with my tube and fin cooler
- added an electric fan in front of the a/c condenser (this required changing the hood latch mechanism from stock to hood pins to buy the needed room up front)
- had the hood louvered - I think it is 8 on each side of the stock hood "bubble"
- changed to a high efficiency engine fan

So, with all this, I have had some improvement, but the tranmission still runs hotter than the recommended 175F maximum. When I am trailering my boat, or in hot weather without the boat in stop and go traffic with the auxilliary fan running the transmission still runs at over 250F. I already had to have my tranmission rebuilt once (and had it beefed up at the same time), for some serious $$$, and I like to prevent having to do that again. I understand that heat is the tranmissions biggest enemy, so I am looking at other ways to reduce the heat build up in it.

Any thoughts?

Brian

 

[Broncobowsher]

Sounds like the engine is doing well, so off to the transmission.

Where is the transmission gauge mounted? Is it in one of the cooler lines or the pan? If it is in the line coming out of the transmission then there may not be anything wrong. If it is in the pan then you need some help in the cooling department. If it is in the return to the transmission after the coolers then your coolers are not working at all.

As far as the cooler mounted on the frame, that isn’t right. What kind of airflow is it getting? Sounds like it is either getting hot air off the engine or no airflow. My guess is no airflow. At least move the cooler to in front of the radiator. Coolers don’t work unless they get a lot of good airflow through them.

Another question is what tire and gears are you running? If your highway driving RPM is too low and close to the converters stall speed then the trans will run hot no matter what. 3.50 gears and anything over 31” tires will cook the trans while towing. 4.10 gears shouldn’t pull anything over a 33” tire. Please don’t tell me they put in a high stall or performance converter. If they did that then there is no way you can make that trans run cool enough to tow with.

 

[Broncobowsher]

Also 175° is a great number in theory. And it is a very good number to aim for during normal operation. But an occasional climb to 200~210° during a long pull up a grade or for a short time towing is nothing to worry about. 250° is warmer then I would want to see as a pan temperature.
Over 200 for everyday use is warmer then I would want to see. That would mean that there is no reserve capacity for when you want to actually work it, such as towing a boat or powering up a hill

 

[76Broncofromhell]

Dump the pusher fan as it blocks a vast majority of air in front of the radiator and only slows down the air a mechanical fan pulls.

Put the stock fan back on it with a shroud. Seal all the holes in the core support. Trim your fenderwells or put a body lift on.

How big of a transmission cooler are you running? I would recommend at least a 12 x 18 cooler if you are towing with it and aren't running it through the radiator.

 

[broncnaz]

Get a transmission cooler with a fan attached to it and run a remote filter to increase fluid capacity. I agree with the others you dont have enough air flow with frame mounted coolers.