Can I adjust speedo for new gears 4.10's and tires 33's without a tuner? Will the dealer do this? Its a 2004 screw 5.4 4X2

 

No. You need a tuner. Also, if you change gears and tires, there is no way to know how many tire revolutions per mile to set the computer at. You can look up the revolutions per mile for your tire and get close. When I tried this, it said I needed 595 revolutions per mile for a 34" tire. I ended up setting the computer for 625, after playing with settings and seeing how my speedometer compared to my GPS. I have that sucker dialed in now The dealer can do it for you, if they know the correct TRPM.

 

Yes the dealer can change the gear ratio. They are limited as far as which ones, but I believe 4.10 is an OE ration. Cost would probably be around $80.

 

Got it, but a tuner will work huh? What about someone else who has a tuner I can borrow or are they specific to the vehicle once you have one?

Sorry about the questions, just tired of not having my speedo right.

 

Tuner would be specific to year, model, and engine. Also, if your computer needs to be updated, you would have to use the tuner to set it back to stock. I do not think that is necessary if done by the dealer.

 

Cool, thanks