Correcting Your Odometer (writeup with pics)

dynamite44 said:

nicely done.
i wish it had pictures that popped up, but other than that, great.
to post pictures, type in

do that around every picture and they should pop up.

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Mambeu said:

It seems like there have been a lot of questions recently about changing odometer mileage. I just swapped in a new cluster, and successfully changed the mileage on the new odo to match the old one, so I took it upon myself to do a writeup. This writeup is specifically for RENIX XJs/MJs, with a mechanical speedometer input, but I would guess that the procedures for a 91+ would be similar.

DISCLAIMER: This is intended as a guide for those who would like to change their odometers to reflect the actual mileage of their vehicles. Using the procedures outlined in this post for any other purpose may be illegal in your state/country. Check your local laws if in doubt.

You'll need a Phillips screwdriver, a pair of needlenose pliers, and two small flat-bladed screwdrivers, or two awls, or two thin nails, or similar implements (I used a handle-less screwdriver blade and a dental pick).

Start with the cluster out of the Jeep (I'm using my old cluster for this, since I didn't think to take photos when I did my new one).

Remove the four screws around the edge of the clear plastic cover. The clear plastic cover and the colored plastic surround simply lift off.

There are three screws that hold the odometer/speedometer assembly in place. Two in the back, one on each side of the speedo input shaft:

and one in the front, at the bottom right of the speedometer (next to the '07'):

Take out the three screws and jiggle the speedo shaft a bit, and the whole assembly will come right out.

Once you get it out, take a look at it. Try spinning the input shaft, and watch how slowly the gears turn. You can roll it forward (much, much more quickly than with a drill) by spinning the white 'tenths' wheel, but that's still really slow (I rolled mine forward almost one thousand miles that way before figuring out the easy way, and that took about two hours of spinning it nonstop, which, needless to say, was more than a little boring). This is what you'll find:

If your cluster has a trip odometer, it will look much the same. The trip odometer is easily removable (two screws), but it's not necessary to remove it.

Now comes the tricky part. Look at the photo linked to a few lines back (269_6929.jpg). Do you see the c-clip to the left of the number wheels? If not, it's circled in this picture:

If you can get the c-clip off, you can slide the number wheels over, off their little 'detents', and spin all the numbers freely. I got the clip off by holding one end still with the small flat screwdriver blade, and using the dental pick to push the other end off. Remember, these were designed to prevent people from tampering with them, so it may take you some time to get it off. When it does come off, there's a good chance that it will fly across the room, so aim towards something like a white bedsheet on the floor, so you can find it easily.

Once the c-clip is off, slide the end-wheel over. Apologies for the crappy photo.
http://i18.photobucket.com/albums/b148/platinumkow/Odometer/269_6937.jpg[img]

To change the mileage, pull each wheel, one at a time, away from the wheel to its right (so to change the 'hundreds' wheel, slide it away from the 'tens' wheel, et c.) about an eighth of an inch or a little less, and it will rotate freely. Then slide it back, making sure that it is seated securely and lined up with the wheel you pulled it away from.

Once you've changed all the wheels, so the mileage matches your old odometer, use the needlenose pliers to replace the c-clip.
[img]http://i18.photobucket.com/albums/b148/platinumkow/Odometer/269_6939.jpg

Then it's just a matter of replacing the seven screws that you took out, and you're done.

This is my first writeup, so comments are appreciated.

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montanaman said:

I hate to say this, but the 91+ is very different. There are a lot of electronics installed, and the odometer is completely buried. Once you get to the odometer, there is no simple C-clip. It's a much more complicated process.

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Rick Anderson said:

I've done it, but I broke my speedo, it will no longer register any speed so yea, I wouldn't recommend it on the 91+ unless you figure out a different way to do it.

Swapping Speedo's between clusters should work, provided they are compatible clusters. I'd think swapping speedo's between pre/post 91 clusters wouldn't work because the circuitry that supports the speedo is likely very different between the two.

I will likely swap the speedo between my clusters, to get a good working speedo, to replace the speedo I broke in the fully equipped gauge cluster.

The problem with swapping speedo's, is that the style of the gauges changed quite a bit over the years and between models. The full gauge cluster I got off e-bay, had the all the gauge faces in Semi-Gloss Black, with White Numbers and Red Accents. My original cluster has charcoal faces with blue accents, the needles are different colors also. So the Speedo is going to look out of place in the other cluster.

Why changing the odometer on a '91+ doesn't work? The odometer mechanism are totally surrounded by a metal/plastic cage, you cannot get into it to change the odometer unless you break the cage or remove the speedo gauge face. To pull the gauge face will require removing the gauge needle.

Thats how I broke mine, I pulled the gauge needle, it wouldn't go back in, and after hours of trying to re-insert, including even taking apart all the parts of the speedo and its servo drive, I had to use some excessive force to get it back in and that needle hasn't moved since. Yes you can move the needle by hand, but I've obviously screwed up the internals that drive the needle.

Other methods to change the Odometer for a '91+. The motor is inside the cage, so you can't remove it and drive the numbers with a drill, without doing all the garbage that I did above.

Your best chance is to probably disconnect the wiring connector for the motor for the Odometer and try to apply some voltage to the motor and drive it. I don't know if that will even work, the odometer motor could be a phased servo motor that requires some sort of differential voltage applied to different wires to get it to spin, if that is the case, then you have an even tougher job.

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