I just got my 285's put on a while back and now my truck seems to be shifting a lot more like it's hunting for the right gear. Is this normal? Do I just need to add a little power to my stock truck to keep her in a higher gear or go to the dreaded dealership and let them tell me everything is okay? Thanks for any help anyone can provide.

 

Reset your pinion factor and it will be a lot better. Unfortunately the dealer has the DRB tool to do this and, depending on the dealer, it will cost between zero and $90. Also you may find Tow/Haul works a little better until you get the pinion factor reset.

I've head mine set twice at no cost but some service writers don't even think it can be done or they just charge an hour for a two minute adjustment.

Wetspirit

 

... also make sure you have a good ground for the OD and TC solenoids.

 

I already had the dealer reset the pinion factor, cost $51. The speedo is right on now, I checked it with my GPS. It wasn't very far off before the reset but I did it anyway. Where would I look for the TC and VB grounds? I don't remember it doing this with the stock tires on the truck. TIA.

Phil