highway observations

[flatlander]

I finally got a chance to pull the TT with that damn truck, and I have some concerns. I still have the overheating (225) problem, which I will address. But at 60 mph with EGT at 500-650 5 lbs boost, the transmission gauge reads 250+ the whole time. I'm going to buy a digital "point and shoot" laser type thermometer and see if my gauge is accurate.

My sending unit is in the trans filter head which is about 2' from the outgoing tranny cooler line. I run through the radiator then to an aux cooler in front of everything then back to the trans.

I also noticed that anything above 60 and the EGT would rise dramatically (damn 3.08 gears), but I could hold 60 with no problem up or down hill.

 

[krawlr]

From what I understand the fluid to the cooler is straight from the torque converter, the biggest heat generator in the system. I welded a fitting in the pan of my Toyota and put the sensor there. The readings are more stable and seem to go along more with the loads it's under. My readings at the line were all over the place.

 

[Exekiel69]

With 3.08 gears the tranny is been forced going up hill at 60mph (I'm asuming you talk about the 84 truck) so the tranny temp is no wonder, but You can allways install an additional cooler in line with the stock one and that will keep temp lower. The coolant temp well that is a different story, how old is the rad? how old is the clutch? do you hear is engaging? You can get a modified fan clutch and when you do also get the t-stat they sale with it and install it, you'll see the temps will be lower by 10-20f.

 

[Diesel JD]

Yeah my truck does get hot as well when towing and A/C on and its hot. The hottest I ever got it, except for the air lock event, was 229* last year and that was towing in traffic with the air on. What should happen is that it should heat up to 215-220 and then the fan clutch should kick in and drop that temp back down to 195-200 pretty fast. Good luck fixing it,
J.D.

 

[MIDNIGHT RIDER]

For a no-non-sense fix on the coolant temperatures, pin the fan clutch, such that it turns at engine speed at all times.

Contrary to what the dramaticists will say, you won't notice any loss of power.

I have done this on several different vehicles, over the years, with no adverse issues.

Like most earlier vehicles, my 78 Chevy never had a fan clutch.

I just drill through the clutch housing and slide in a grade 8 bolt, then peen the nut on.

Once you do this, you can eliminate the fan clutch as a cause of your heating issues.

Also, if your fan clutch is mal-functioning, the transmission cooler will not perform as it should, as no air is being pulled through.

 

[bikepilot]

I notice a power loss just when the standard fan clutch kicks in, when towing up a hill and it starts pulling I have to give it a noticeable amount more fuel to maintain speed. I can see pinning it for diognostics when your pretty sure yours is bad, but if the fan clutch is working correctly I don't see the point. Fuel mileage will suffer for sure.

My Trans (e40d) always stays below 200 and usually hangs out around 170. My EGT's are much worse than yours though. I'll be well over 600 before I see that kind of boost.

best of luck