speedo calibration/correction
Thread Starter
|
Senior User
Joined: Feb 2007
Posts: 103
Likes: 0
speedo calibration/correction
I recently switched from my stock 205/ 70 / r14 wheels and tires to a set of 30 x 9.5 r15's.
Needless to say my speedo is way off. I know there are a few ways to correct it, but I want to be able to change it easily back and forth. I am going to run my better set of wheels in the summer and switch to my smaller, stock set in the winter.
Would it be best to get one of those units that hook into the v.s.s., or should I try a programmer than plugs into the port under the dash?
I posted this here because I want want to advice of a ranger owner who has had to correct their speedo.
Needless to say my speedo is way off. I know there are a few ways to correct it, but I want to be able to change it easily back and forth. I am going to run my better set of wheels in the summer and switch to my smaller, stock set in the winter.
Would it be best to get one of those units that hook into the v.s.s., or should I try a programmer than plugs into the port under the dash?
I posted this here because I want want to advice of a ranger owner who has had to correct their speedo.
Cargo Master
Joined: Feb 2002
Posts: 2,414
Likes: 22
From: Tucson USA
yours is a 97 mine is a 94, I went to the dealer and had them look up the drive gear for my change. I bought the purple (?) gear they said would be right, but went back to original and just made a check of how far off it is and it is 5 mph off over 60, losses 1 mile every 25.
I run 235 70 15's so I dont have anything close to you. what I did was run to work (75 miles 1 way) started at a mile marker and noted the milage then compared when I got to the last one, I also ran a stop watch for 10 miles @ a steady 60 mph and got my speedo info. I further used a GPS unit to verify speeds. There are several sites where you can get time milage conversions. You can also get one that will give info based on your input as to gear ratio, tire sizes (radius/diameter) etc.
Changing the speedo gear is easy pull the cable from the trans pull a circlip pull the gear, reverse procedure.
I run 235 70 15's so I dont have anything close to you. what I did was run to work (75 miles 1 way) started at a mile marker and noted the milage then compared when I got to the last one, I also ran a stop watch for 10 miles @ a steady 60 mph and got my speedo info. I further used a GPS unit to verify speeds. There are several sites where you can get time milage conversions. You can also get one that will give info based on your input as to gear ratio, tire sizes (radius/diameter) etc.
Changing the speedo gear is easy pull the cable from the trans pull a circlip pull the gear, reverse procedure.
Thread Starter
|
Senior User
Joined: Feb 2007
Posts: 103
Likes: 0
I drive 70 miles one way to work, and after I changed my wheels the trip odometer read that it was 58 miles to work, so I know the speedo is way off. Do they make the speedo gears in a wide enough range to correct that big of a difference?
Post Fiend
Joined: Jul 2005
Posts: 8,462
Likes: 4
From: Durant, OK (SOSU)
A) 205s are entirely too small...I've never seen anything smaller than P225 stock.
B) The '94 is gear driven, your '97 is an electronic speedometer. Your dealer can correct this in just a few seconds by plugging into your truck and entering the new size (and most will free of charge if you're polite about asking and they aren't too terribly busy). If you know anyone with an OBD-2 programmer for Ford, they can correct it as well.
I'd suggest calling the dealer, especially if you bought it new, and see if they'll do it, and when would be a "light" time for them.
B) The '94 is gear driven, your '97 is an electronic speedometer. Your dealer can correct this in just a few seconds by plugging into your truck and entering the new size (and most will free of charge if you're polite about asking and they aren't too terribly busy). If you know anyone with an OBD-2 programmer for Ford, they can correct it as well.
I'd suggest calling the dealer, especially if you bought it new, and see if they'll do it, and when would be a "light" time for them.
Thread Starter
|
Senior User
Joined: Feb 2007
Posts: 103
Likes: 0
My grandfather bought the truck new, and I know he never put tires on it so, ya believe it or not the 205's were factory. When I got it almost 2 years ago now it only had 29000 miles on it.
I looked into the programmers today, and I couldn't find one that was for the 3.0 v-6's. Was I looking in the wrong spot? I don't want to be able to change it myself, so I can change it back when I run the smaller tires during the winter.
I looked into the programmers today, and I couldn't find one that was for the 3.0 v-6's. Was I looking in the wrong spot? I don't want to be able to change it myself, so I can change it back when I run the smaller tires during the winter.
Post Fiend
Joined: Jul 2005
Posts: 8,462
Likes: 4
From: Durant, OK (SOSU)
Your mileage outta go up a lot, the smaller sized tires are probably really making that 3.0L rev on the highway.
There is a speedometer correction thing, let me see if I can find it. And for the life of me I cannot. I remember seeing one of these a while back, it's basically just like a regular programmer but only adjusts the tire size.
Programmers are pretty much universal. I know many of the guys like SCT or Diablo, both of which are available for the Ranger. It's a lot of money to just adjust tire size though.
There is a speedometer correction thing, let me see if I can find it. And for the life of me I cannot. I remember seeing one of these a while back, it's basically just like a regular programmer but only adjusts the tire size.
Programmers are pretty much universal. I know many of the guys like SCT or Diablo, both of which are available for the Ranger. It's a lot of money to just adjust tire size though.
