Odometer rollback

[jrcook320]

I finally made time to go find my old speedo and take some pics. Here is how you do it. I trust anyone who does this will only use it for good intentions, i.e. rolling it back to match the mileage on a new engine, or setting a new speedo to match the actual mileage of your car.

Once you have the speedo out of the car, remove the backing plate/drive assembly. It will be held in by 3 screws. Make sure to hold the speedo so you don't scratch up the face or brake off the needle.
See pic 1

Use needle nose pliers of vice grips to pull the shaft that holds all of the gears out. Both ends are flaired to keep you from doing this, but you will only have to pull one side out. You will have to pull hard, but be carefull. You may have to file a little at the end you are trying to pull through the hole, but don't file so much that it just slides out or it won't stay together when reassemble it.
See pic 2

You may be able to roll each counter to 0 without removing the gears. I was able to use the gear to roll each counter to where I wanted it. If this doesn't work, you will have to remove the gears, they just slide off of the shaft. It will be tricky to keep everything lined up when you reassemble it. Just have patience. All of the gears will have to line up perfectly. Just gently tap the shaft back through the hole, reinstall the drive assembly and you're done.
See pic 3

[jjgbmw323]

Ok.

Thanks, I have to do this when I finally get my 11 year project back on the road.

Appreciate the help,

Joe

[blitzed310]

Thanks, good write up Josh

[bread320i]

11 years... My god thats older then me

[kdanielson]

Wow, now I can have a 10,000mi '82 320is! Just kidding....
ken

[jrcook320]

haha, hey, mine says 18,xxx miles. But who cares? Thats the mileage on the motor, and the chassis and tranny have even less, and I never intend to sell the car. The car title has a note that says "not actualy mileage", so it's legit.

[Jeff M3]

I have often thought of it like you as well ... and even if you are going to sell the car, chances are it would be to another bmw enthusiast that wouldn't care about the mileage anyway.

I will be doing this as soon as I can find a 6cyl/subframe/tranny to throw in my car

[shadyduk1979]

all i did was remove the top pin (pic 2) and i got it all set. - chris

[bflan2001]

i'm trying this out on a 140 speedo i have...i was able to adjust the mileage, but it looks like the only way to remove the odo assy is to first remove the gauge face, which also requires removing the needle...how did you get your odo off with the face intact?

[bflan2001]

double-post :/

[skyflyer]

bookmarked. thanks!!!

[M202002]

thats a hard way....theres a heaps easier way...

[DrewDude320i]

My car will have a lot of road grime and rust for having less than 1000 miles on the odometer

[bflan2001]

thats a hard way....theres a heaps easier way...

care to share?

[fullswing]

thanks for the writeup

[M202002]

i'll upload a pic in a few days

[Dave1965]

haha, hey, mine says 18,xxx miles. But who cares? Thats the mileage on the motor, and the chassis and tranny have even less, and I never intend to sell the car. The car title has a note that says "not actualy mileage", so it's legit.

Hey Josh, while you were in there did you see anything that could be "adjusted" to correct for a fast reading speedo? I'm thinking either tape/foil in between the rotating magnet and needle or some clearance that could be increased by shimming with a spacer/washer?

I'm about 5mph fast...

[AlaskaBimmer]

Are those the gears that teeth break off of and cause the odo to sporaticaly work? I've never been brave enough to dismantle the baurs spedo since I don't have a spare 6 cylindar spedo to put in there if I break it.

Mine at times will stop spinning until it catches again and works. I know I can get a replacement gear, I just don't know which one it is or how hard it is to repair.

[jrcook320]

no, that gear is on the side. see the faq, there are links to repair threads with pics.

[AlaskaBimmer]

I will have to dig back into that thread, i want my odo to work properly....

Thanks

[hamonbagel]

Hey guys, here is a different way to do everything that was asked above...

To adjust the mileage, there are a set of 6 course gears right above the odometer numbers. Use a small screw driver and gently pry the bar away from the numbers. The center one will be easier than the outer ones because of leverage. There are two positions for each number so make it click twice. You can see if things are lined up in the face.

To adjust the speed indication:
This will only work on cable drive speedos, E21, E12 and older... Gently lift the needle over the stop and see where it points without the spring load on it. Scratch the outside edge so you will know were it was. On the backside, insert a small flat blade screwdriver into one of the screw holes and wedge it so the speed-cup is locked. The hold the speedometer needle by the center and twist it left or right depending on which way you need to adjust. Too fast, you need more spring tension which means counter clockwise and vice versa. If you are talking about reading 70 and you are going 60mph, only move the needle about a 1/16th of an inch. Trial and error using a GPS is the best way.

"My odometer works sometimes or not at all."
There are two gears on an E21 to look for. The first is the outside nylon gear. Look closely at the center for a hairline crack. The other is the "Lead Gear", which is located at the end of the numbers. If it slips at all on the shaft, it needs to be replaced. Push on it with a screwdriver. If your shaft has pulled out and you need to push it back in, it's the lead gear. It will not look broken but both gears mentioned have to be tight on the shaft for the odometer and trip to work.

If anyone has more questions, just call me anytime 757-593-3478. Glad to help out.

Jeff Caplan
Odometer Gears Ltd

[jrcook320]

Wow Jeff, thanks for the input. I'm pretty excited to check out that speedo re-calibration technique.