So I bought a boat yesterday. Little 94 Sunbird Stinger ski boat. Weighs less than 3k. My truck (08 h3 3.7) power wise, did not struggle a bit. After getting off the highway and driving through town it seemed like the tranny was overheating and would start to make a god awful whine. I'd pull over give her a break and let it cool down and I could go again for a little ways before it'd do it again and repeat the process. Anyone have any experience with something similar? It is my understanding that there is no true trans cooler on these trucks and would adding one remedy my situation? Pending I didn't kill my transmission already 😅

 

When was the last time you changed the trans fluid and filter? Add to that question Transfer Case fluid, Front & Rear Diff lube? Miles on the truck? The Trans is cooled by a loop through the radiator.

I do not know what the whining sound was you were describing. Heat shields can make a bunch of strange racket on occasion.

I towed a 23 Big Block Chaparral Bow Rider on Tandem Trailer back to NE of Detroit from South of Milwaukee with my old 07 H3 in full off road trim w/o issue.

 

Been towing my tandem Sea Lion with a 23' + and mercrusier 5.0 with no problems for many years. Like others have said keep up on your fluids and air pressures. You should be good to go.

 

Ended up throwing a "P0741 - Tq converter clutch circuit performance/stuck off". Dropped the pan and the fluid looked pretty typical for a 120k mile car. I changed the TCC solenoid associated with the code, cleaned her up, changed the filter and added new fluid this evening. Just took for a test drive and she's shifting fine, lock up is working properly, no whine, and no codes thus far.. fingers crossed but hopefully that did the trick. May still add an external trans cooler for extra comfort. 4L60E's are delicate little flowers lol

 

Proper maintenance and fluid quality is the key! "P0741" The TCM commands TCC ON, and the TCC slip is 150 RPM or greater for 5 seconds, 2 times during the same ignition.