Originally Posted by Eric99tj
That is the first time I have heard of the OD being a weak link the 5600. The only weakness I have heard of is the input shaft bearing not getting enough oiling so some guys are running an extra quart or two of oil in them. Maybe that is what you where referring to. I always pull in OD with my 5600, but I do not pull as often as you though.
The OD design is similar to the 4500. I'm not sure if they had as many issues, but I have read they don't like towing. I've also heard about the input issue, as well as 2nd-3rd gears burning up. My trans guy has seen many bearing and OD failures with the 5600. However, in a DD/moderate towing situation I wouldn't be scared of it.