tumper93

2006 4x2, can the dealer change the ring and pinion setting with their scan tool? From 3.73 to 4.10?

j-fox

They should be able to. But, I have read where some techs don't know how. Do a search before you go.

napa169

Hey Tumper.

From what you are saying, and I could be wrong, it sounds like you want to change the rear end gear ratio from 3.73 to 4.10.

This is hardware change, not a software change.

(Scantool can change the software settings in the computer on the truck.)

You would have to remove the 3.73 gearing in the rear end and replace it with 4.10 gearing.

Baja

Yup, Napa169 is right, the ONLY way to change the ratio is to change the ring and pinion itself. You will have to remove the differential to do the job.

no_6_oh_no

Can't change the physical gears with it but can change the revs per mile on some or tire size on others to adjust the speedo if thats what you are wondering. If you are changing gears and wondering about resetting the ratio it is not needed.

dieselweaver04

how did that work for you iam thinking about changing i have 410s i would like a higher gear. I have 35" tires does that matter.

NDanecker

Boy I wish they could do this with a simple hook-up with the Scan TooL!

If you change your gears you don't have to worry about changing or updating the ECM with respect to your speedometer. Vehicle speed is picked up thru your ABS sensors (2 front at each wheel and 1 single in rear axle). It is done AFTER the gearing so no matter what gears you have the speedometer will still show the correct speed as it is picking up your axle RPM's, not driveshaft RPM's.

However, if you swap/change tires you will need to update the factor. Again, it is done thru the ABS section of the ECM. Generally most dealers (so I heard and so experienced myself with my dealer) don't know how to update this. Just tell them its located in the ABS brake section, not axle section of the scan tool.

Also, I'd recommend going to the tire manufacturers website and get the revolutions per mile while loaded. If they use this number vs. the standard tire size listed you'll get a more accurate speedometer. I've been thru all this ... and confirmed my speedometer with radar gun and GPS unit.

kprc51

Went through this just now. changing your settings by the dealer is necessary when changing the tire size only, when changing the gears, it is not necessary as the speed sensor is on the rear ring gear.

JR

SAS

What are dealers charging to update for larger tires? I just put on LT 285/75 R17 tires and my speedo is 4-5 mph off.

NDanecker

If you are in for service they may just do it for free. It takes longer to get the scan tool out of its case and hooked up then to make the change.

Mine didn't charge me anything as I was there for an oil change. But.....he must of forgot to press OK the first time around as when I left the parking lot speedometer said I was driving 80 mph when I was maybe doing 30 mph or so. Second time around it came out perfect!!!

I highly suggest you/they specify # of revolutions instead of tire size. Using the manufacturers specs for a loaded wheel will give you more accurate results then simply selecting a tire size from the list DC offers (in the scan tool). I reset mine after the dually swap and got mine 'dead-on' according to a radar gun and GPS.

SAS

Thanks, I do my own service so I will call around a see if I can find a dealer that knows what I'm talking about. I have the rev. number from my tires spec. sheet

NDanecker

As a side note....my VW Jetta is approximately 6.8% high (when crunching the numbers). This means the car has 6.8% more miles on the odometer then actual. Not happy about that as this directly effects resale value!!!

I wonder if they do this just to make it look like their cars get better mileage then what they actually do!