Anyone know what to tell the tech. at the dealer so he can calibrate my speedo with the 315/70/17's i just put on?

 

BF Goodrich specs for the 315/70R17 show it at 601 Revs/mile @45mph.

-Muzzy

 

The number I used was 600, just to keep it even; my gps says the truck thinks I'm going about 3/10th of a mile further each 35 miles, or so...

Otherwise, something around this figure should work.

Don't forget, averaging higher speeds will make for a larger diameter (I think), & that will introduce some error.

Also, as the tires wear down, the diameter will shrink somewhat.

I'm just going to leave the number where it is for now, & see how it plays out over some time..

Rene

 

???I did not know they could recalibrate the speedo on these trucks??? Explain...please ???

 

The dealer can recalibrate the speedo with their DBR III or whatever they computer is called by correcting the number of revolutions for a given tire size.

 

BamBam:

Here's the quote:

"Just got back from a friend's who has the Dodge DRB 3 tool.

He hooked up the thing to the diagnostic port under the dash, scrolled down to the section on the ABS system, selected 'revs per mile'; I told him to plug in 600 (the range on the screen allowed anything between 400 - 900!!)"

On the ABS menu -

Choice 1 is 235(?) tires
Choice 2 is 265
Choice 3 is "Other"

Pick that, & then you can get 'revs per mile'.

Hope this helps.

Rene

 

Find an aftermarket calibrator, the one I use has a feature to switch between two settings for two different sets of tires. It mounts under the dash.

4x4
P.S. Hopes this helps.

 

Anyone know the correct # of revs with 4.10 gears?

TIA

 

tire revs are tire revs, no matter what gears you got.

Driveshaft revs/mile may vary, but not tire revs.

 

Bulabula,

Your right! I don't know what I was thinking... Sometimes I just have to laugh at myself!!

 

It's 606 exactly. I figured the loaded rollout for the 315's and thats it. Service tech recalibrated mine and I checked it with my gps and its dead on at any speed. Hope this helps!! ;D

 

What exactly do i tell the tech to do? Or will he know.

 

How much are you guys paying for the Dodge ******* to do this?

I am thinking hard about putting on some 225/70/19.5's on my truck.

I'm picking the shortest 225/70/19.5 I can find which is about 652 revs per mile. I should not need any sort of lift right? Looks like 265/70/17 LTX A/S is 657 per mile so I am just a tiny bit bigger than them.

 

[quote author=RACER47 link=board=17;threadid=22481;start=0#msg210096 date=1068957804]
Anyone know what to tell the tech. at the dealer so he can calibrate my speedo with the 315/70/17's i just put on?
[/quote]Give him the number he needs for your tire. He needs the revolution per mile. You should call the manufacture and get that number because no 2 tire molds are the same.
It would simply be a coincidence if a 315/70 BFG had the same RPM that a 317/70 Toyo had.

 

I asked at the dealer here in Traverse and they said it would be one hour service time ($70) so I walked out. > Maybe if I ever end up HAVING to take it in there, I might have them do it.