I have a 93 bronco XLT with a 351 and the auto transmission. I recently moved to 35" tires and 4.56 gears. The truck has about 125,000 miles on it and runs awesome. Since I did that the truck heats up on the freeway, average speeds of between 70-80. I have always had a 180 degree thermostat in place and never had the problem with the 32" tires. I have gone through the water system and replaced the water pump, hoses, thermostat, and had the radiator flushed. I even pulled out the radiator and checked it for mud residue on the outside. The radiatior looked extremely clean inside and has the factory Ford half aluminum and plastic. I had had the truck checked for head gasket leaks and everything seems to be in order. I have the factory transmission cooler also. I don't know what else to do, I would like a larger radiator or if anyone has any suggestions I would be greatly appreciative.

 

There are one or two company's that make all aluminum radiators, Griffon is one of them I think. That and a couple of electric fans should hook you up. Or, you could try some water wetter as a cheap alternative.

BFM
Recycle...crush a chevy

 

Seems that shouldn't happen. Did you find the cause?

 

No I am tired of trying to find the problem, it seems that that the gears are just too big and they cause the motor to rev so high there is nothing I can do. I am going to change the radiator to a new radiator out of a 460 F-350 and that will hopefully solve the problem. My radiator may look clean but the fact is it's problably the original radiator and should be replaced. That is the only thing left. The factory radiator only holds two gallons of coolant which isn't much when your towing in 120 degree weather.

 

If your towing in 120F air temps your bound to overheat.

I am also guessing you have the AC running as well?

I know it makes it hot but you can try next time turning the heater and see if it cools down any.

 

well i agree with jopey, with thoughs high of tempertures and towing the gage is going up. with everything you've checked and changed you did check your clutch fan and if you haven't i'd check it. i have a 87 bronco 351 and i tow a lawm mower trailor running in about 85 to 90 degrees average, if i turn the air on it goes up the temp, anyway my clutch fan is not working real great and it needs to be changed, and it should be checked while your engine is running at normal operating temperture instead of cold, good luck.

 

The fan clutch is a brand new one from Ford. Everything is new except the radiator. I havn't had a problem for a while, but I havn't been to Arizona lately.

 

Well, it may be time to ditch the clutch fan. A clutch fan works on the idea of heat and motor RPM. You effectively raised the cruising RPM for the same speed on the highway. I have run into this on a couple of Mustangs and T-birds. You are running higher RPMS, which in turn shut the clutch fan down. You are cruising at the same speed, effectively moving the same amount of air through the radiator, but the truck is generating more heat. Your best bet is an electric fan or a flex fan. This is what helped on the Mustangs and Birds.

Good luck
Steve S.
54 F-100 (awaiting restoration)
76 F-350 Crew cab (2wd dually, for sale)
77 F-250 Supercab (Camper Special 4x4)
79 Bronco (wife's, restoration almost done)
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