To the PM asking why I didn't talk about a radiator going bad, as it also has these symptoms...
Yes, but the OP somewhere in earlier posts on this thread said it had a radiator leak and had it fixed
So, assumed it was done correctly (assumptions are dangerous, but the OP said had it fixed). Also assumed either new radiator or the old radiator fixed (re-tanked, rod'ed out, etc...another assumption). That means it is or should not be the radiator
Hope they didn't just toss in a bottle of stop leak, one of the worst things you can do involving Deathcool (Dexcool...pink, or red coolant...AKA OAT's, Organic Acid Technology). It will react to form acidic globs that then stick to cooler surfaces (like inside the radiator, which will block flow and acidic means eat/rot the radiator from the inside
Curious why folks are harping on this small block's RPM while towing. The 4L80E is an 'automatic' and just leave it to it's computer to manage it. The manual does say to tow in 3rd, not OD. IF the OP is towing in OD, then the tranny will hunt and over work the gear sets
Gears get hot while working at or near it's design limits. The why differential gears get hot and there isn't a TC in there. Any gearbox will get hot and hotter as you approach design limits. Ditto in an automatic and toss in the hydraulic coupling losses of a TC...an automatic will get hotter than a manual, everything else the same
Of course, Grit and the others who think the 4L80E is failing could also be right, but the OP hasn't provided any info that would point to that. My guess is the fan clutch and is the lowest cost component fix at the moment based on the OP's info posted
