Interesting, but makes me think...Since Chrysler cannot calibrate the speedo to tires larger than 33's, how can they prove that your speedo is not correct using thier computers?

I see where they want 'accurate mileage' to help determine where any mileage warranty might run out, and anything that would cause actual mileage to be questioned could void a warranty, but how would they determine your speedo is off? Maybe drive another car alongside and measure the speed?

And when they flash/upgrade any computer items, does that reset the OEM setup...and cause me to go home and have to reset my tire size and gear ratio with my little box?

 

I called the dealership this morning and asked them. They infact said the same thing, that they could adjust speedo and odom. up to a size 33 tire. he said that there wouldn't be much differnce "at least not enough to worry about" were is exact words. I know if I drive 50 miles to another dealership I would get a different answer.

 

Anything you do or don't do, or how you drive or let it stay parked, or if you off-road or if you on-road, or mod everything or nothing, may or may not void your warranty. That said , now go have fun.

 

Only if it is an FJ Cruiser...

 

Yeah - I think actually that there's a Hall Effect sensor reading speed off of the shaft rotation...so the system needs to know the tire diameter, AND the diff ratio, etc...to know how fast you're going. The tone rings etc...seem to be wired to feed info to the ABS and traction control, etc...but those need to know the ground speed as well.

So, its possible that the CPU has to crunch all of this data to decipher the variations between ground speed, tire speed, etc.

People who swapped in lower gears DID report that the speedo accuracy was corrected...so that leads me to believe that the diff gears' impact upon the shaft speed at a given gound speed is what the Hall Effect Sensor (Three wire) reads the speedometer/odometer off of, rather than the tone ring data used for the ABS, traction control, etc.

The older rigs with mechanical speedo gears were an easier fix, that's for sure.

 

my 35's went on yesterday. I called the dealership this morning and am taking it in tomorrow for them to recalibrate the best they can. they said and I qoute "we will get it as close as we can. It will be alittle but not enough to effect your warranty." I plan on getting that in writting. LOL

 

I believe that the speedometer being "WRONG" is insufficient to VOID a warranty...as its inaccurate by a KNOWN AMOUNT...which is WHY its "wrong".

So - If the inaccuracy is found to be 10% for example, and you have a 100K mile warranty....and your odometer reads <90K or so...you're still under the 10% error....etc.

If you have a LIFETIME warranty...the mileage should not matter, unless you missed maintenance milestones due to the error.

IE: Changing the oil 10% late would be a bogey if an engine lubrication related failure was the bone of contention, etc.



Remember - they can't just "VOID A WARRANTY"...only cover, or not cover, a particular repair...and they still have to PROVE that a particular mod CAUSED the failure....that's the LAW.

 

I am running right at 3000.

I had my gear swap done by my dealer. If you can find a mod friendly dealer that will make a big difference.

 

I have lost my Lifetime warrenty paperwork. What are the milestones again beside oil every 3000?

 

Might be every 6k in the book, the DEALERS used 3K to double the service work.