Odometer Rolling Back/Forward

[Tiggie]

Anyone ever rolled the odometer back or forward on a '79-'87 CV? If so, how'd you do it?

I'd rather not use the drill method or driving in reverse for 50,000 miles. I could go up 3,000 miles if I put in the wagon, or I could go back 56,000 if I put it in the '82.

I don't want to ruin a PI speedo by screwing up the odometer.

[DuceAnAHalf]

why dont you want to use the drill method? using a drill that runs about 1400rpm only turns the needle to about 65mph, so you wont break it

[P72Ford]

You can take them apart. I took apart an old GM unit for a reverse engineering project one time. I had to remove the "reel" from the body of the speedometer. The number rolls all ride on a shaft, at the end of which is a small tab. If you pull the tab up, you can remove it, and the shaft will slide out of the reel housing via the other end. Then, you can set all the reels at whatever numbers you want, and slide them back on that shaft, and slide the shaft back in the reel housing. I didn't break anything, and I had it apart numerous times.

I have played with a certified 140 CV speedometer before, and found it to be assembled in a similar way. If you're careful taking it apart, it shouldn't be a problem.

[Tiggie]

why dont you want to use the drill method? using a drill that runs about 1400rpm only turns the needle to about 65mph, so you wont break it

Well, it'd take two days to get 3000 miles. That wouldn't be so bad, but I really want to put it in the '82 so it would take about a month so get back around to 24,000. Of course if I sell the '82, I won't have this issue.

You can take them apart. I took apart an old GM unit for a reverse engineering project one time. I had to remove the "reel" from the body of the speedometer. The number rolls all ride on a shaft, at the end of which is a small tab. If you pull the tab up, you can remove it, and the shaft will slide out of the reel housing via the other end. Then, you can set all the reels at whatever numbers you want, and slide them back on that shaft, and slide the shaft back in the reel housing. I didn't break anything, and I had it apart numerous times.

I have played with a certified 140 CV speedometer before, and found it to be assembled in a similar way. If you're careful taking it apart, it shouldn't be a problem.

Sounds doable. I could always go to the junkyard and dissect one on site to see if I felt comfortable with it.

I attempted to roll one on my '95 Ranger when I put a tach cluster in. Ford had gotten really good with tamper proof odometers by that point. After some trial and error, I finally ended up just swapping the complete speedometer from my old cluster. Their odometers might have been tamper proof, but swapping the entire speedo was easy!

[P72Ford]

Yeah; try a disposable 85 MPH unit before you mess with the "holy grail", so to speak.

[mrltd]

it's simple to do.... tap the one pin out, set the numbers, tape em in place (to keep them perfectly aligned) and tap pin back in. It's a 10 minute job.

[gadget73]

What he said. Takes almost as long to get the speedometer shell apart as it does to set the numbers.