REV overheating - normal?

[thoner7]

Have the same issue in my m1152 with gfd. Getting hot on highway. Nothing off-road or traffic jam. Can be the visco clutch or the thermostat doesn’t open to heat up the radiator and bring heat to the visco. Have to check tomorrow the thermostat.

I replaced my thermostat first. Didn’t fix it. Haven’t had time to try the fan clutch yet

 

[engele]

Is there an after market clutch available? I just found ones with 400$+

 

[thoner7]

Where did you find that price? I linked to the one previously but apparently it may be old or expired? Idk. I was gonna order from a known quantity and get some other parts when I do.


How does one know when it would be worth replacing the radiator? Radiator has to be removed to get to this fan clutch, so now would be the time for me to do it. The original radiator is somewhat rusty and corroded, which is weird for a brass radiator ? I assume it’s surface rust but I’m a novice. If I replace it, I’d like to have a new radiator in hand before doing the repair. I’ll post some pics. Input appreciated.

 

[thoner7]

More - really hard to capture with the camera

 

[Coug]

With any situation where the gauge in the truck is telling you something is wrong, it's usually a good idea to use some other measurement device to verify that the gauge is functioning properly before you start throwing money at replacement parts.
A laser thermometer aimed at the neck at the end of the radiator hose is a good place to start, as well as immediately next to the sending unit.

 

[Mogman]

More - really hard to capture with the camera

The shell around the radiator is steel not copper

 

[thoner7]

With any situation where the gauge in the truck is telling you something is wrong, it's usually a good idea to use some other measurement device to verify that the gauge is functioning properly before you start throwing money at replacement parts.
A laser thermometer aimed at the neck at the end of the radiator hose is a good place to start, as well as immediately next to the sending unit.

Had the same thought. The gauge seemed accurate enough. Confirmed with a laser.

I ordered the fan clutch today. I’ll post some pics of the radiator when I get to the repair

 

[williamh]

The outside of the radiator is nothing compared to the inside. Corrosion that causes high temps is the inside passes clogged.

 

[TOBASH]

Replace with OEM. Record, champion makes an Aluminum 4 core unit. Cheap. Easy to obtain. Some people claim problems with quality, no quality problem on my spare radiator.

 

[thoner7]

Updating on my repair to help future readers:

I got the radiator out and the fan clutch swapped. After cruising on the highway in 80+ degree heat I can confirm the fan clutch was the issue. I never got over ~212 which is the fully opened temp of the thermostat as I understand it. Thank you very much to RetiredWarHorses for your expertise. This made the repair way easier. Thanks to all of you experts helping out around here!!!

The fan didn’t come apart or go together like the TM showed. The 6 bolts that hold the fan to the clutch, and the 4 bolts that holds the clutch to the Geared Fan Drive, are all accessed from underneath the Fan. The tm shows the fan clutch bolting on from the top down, but it actually bolts from underneath the clutch.

After doing it, I’m fairly confident I could have replaced the fan clutch without pulling the radiator. if you remove the top passenger side corner of the radiator shroud, I think that would be enough clearance to reach in and access the necessary bolts. You can see most of them from under the truck as well, looking past the Diff. Give that a try if you ever need to replace yours.