I use to have a 2000 Limited 2WD and never had problem towing with the Overdrive off. Towed a 23 Ft Eliminator with it (with the Overdrive off)and it worked fine. Sounds like you should have the dealer check out the tranny. If you do not get much feedback here, try one of the Tundra owners websites...I forget the one I used to check, but there is another one called Tundrasolutions.Com...maybe someone there has had the same issue. Good luck.