I've read in a couple different posts long time ago that the hypertech can't/didn't fix a couple of speedos on certain year trucks. Will it fix mine? I think, the last time I looked at it, the sticker on my door said 3-98, guessing March of 98. Anyone know about that?

 

When you say "fix" am I to assume you mean "adjust for non-stock tires/gearing".

My understanding is that 97 and back used a gear in the tranny (old school style) to calibrate the speedo/odo assy. 98 and newer used the speed sensor(s) and IIRC the Hypertech will compensate (or was it Superchips?).

 

yea, thats what I meant, thanks.

 

I know there's been references to '98.5 trucks so I'm assuming there must be some changes for the earlier '98's. I don't what the changes might be, all I know I was able to adjust the speedo with my Superchips on my '98 (build date 11-97).

 

The speedo can be correctly set by a properly trained technician at the dealership if he follows this
(not well known) set of instructions:
------
originally posted by grfraz
Augusta GA

Here is the recipe.

1) Have the tech plug his hand held into the OBD port and turn it on. A menu
screen comes up with a bunch of info. Select YES to go to next screen.

2) On this screen select menu item 1, "DRB III Standalone" to go to next screen.

3) On this screen select menu item 1, "1998-2005" to go to next screen.

4) On this screen select menu item 1, "All" to go to next screen.

5) On this screen select menu item 5, "Antilock Brakes" to go to next screen.

6) On this screen select menu item 9, "Miscellaneous" to go to next screen.

7) On this screen select menu item 2, "Set Pinion Factor" to go to next screen.

8) On this screen there are a several tire sizes and Other. Select menu item 8,
"Other" to go to next screen.

9) On this screen there are two items,
an Axle Size, (9.25" on the 1500's and 10.5" on the 25/3500's)
and Other.
Select menu item 1, "9.25" Axle" (or 10.5 if your case)
to go to next screen.

10) You have now arrived at the point in this process where you will enter the
revolutions per mile for your tire size.
Select the menu box for RPM.
It will indicate 400 revs per mile initially. Here is where the tech will change the revs per mile with either
the up or down arrow. It will take a while to go from 400 to 604 (for the BFG
315's) so be patient. As you are waiting on him to finish, take this time to let
him know that he shouldn't charge you more than say $20.00, especially since you
trained him on this procedure.

11) The last step is to select "OK" and the changes will be excepted, then the
hand held will display "Reprogramming Successful".

Good luck!

======
There is an online Java calculator to compute approximate
revolutions per mile at:

http://pw1.netcom.com/~sgalaba/tiresize.htm

 

the above wont apply to you if you have a 98. The 98s read the speed by a sensor on the rear differential housing. It counts the teeth on the tone ring.
I have not encountered a 98 that doesnt take speed from this area, so I dont know if certain 98s are different, but I know 98.5s definatley have it.
So
If you get the programmer to do that or have the dealer do it you'll be wasting your money

 

Hypertech application chart: http://hypertech-inc.com/dodgefeaturechart.html

Second from the bottom (P/N 50003) is 98 5.2/5.9L ... claims to adjust for tire size.

Isn't 98.5 when Dodge changed to the 24V CTD?

 

yes it is (CTD), my 2000 hypertech did not fix my speedo...