Last October, the transmission in my tow rig (1999 Suburban C1500) started making bad noises, so I parked it. Besides my boat, I also use the truck to tow my race car. The truck had a stock 4L60E in it, and after dropping the pan, I confirmed that it was dead.
Initially I thought I'd just sell the truck and look for a newer 3/4 ton truck, as I have wanted to upgrade from a 1/2 ton for a while. But....after looking at prices, I decided I'd be keeping my C1500 and just replace the transmission, lol. Instead of going back with another 4L60E, I decided spend a little more to upgrade and swap to a 4L80E - the transmission that came in the C2500. I had a local shop source a core, perform the rebuild, and also install a towing upgrade package.
My brother and his son came up at the end of December and we performed the swap. Besides the new trans and torque converter, I had to modify my driveshaft, reflash the computer, replace the trans cooler and lines, and do a little re-wiring, but now I have what I think is the most important part of the 3/4 ton package - the stronger transmission. I'm hoping this thing gives me many years of worry-free towing.
With things warming up in TN, I'll be de-winterizing the boat in the next couple of weeks and we should be on the water by the end of April.