I'm too embarrassed to say how I did it, but I broke my speedometer. I'm getting a replacement, and I will want to set the replacement odometer to the same miles as the original (155125 by the way). Any help/advice out there?

 

you can't. the mechanism is built to prevent tampering (otherwise, used car dealers would be setting that 350,000 miler to 30,000 and selling it as a cream puff)

if you try, you'll break stuff.

now, what part of the speedometer did you break? if its the circuit board, and your replacement is identical, you can swap circuit boards without *too* much trouble (its still kinda tricky, gotta unsolder some stuff).

do be sure your replacement is the exact same type, some cars use VDO, others use Yazaki, and different years are often not interchangable.

 

You certainly can: you can do it yourself if you have the patience or a shop can do it... And, big surprise--car dealers and many others do roll back miles all the time.

Actually, since you have the old odo, you can just swap the tumbler cylinder with the miles into the new unit, unless you broke that, but I doubt it...

 

lev: I thought all odometers since the 1970s had to have antitamper stuff so if you tried to tweak them, they were designed to break? sure, you could hook up a pulse generator to a digital speedo, or an electric drill to a mechanical one, and "drive" 140 miles an hour for a few days, but it would take a LONG time to rack up 100k miles or whatever.

 

OK, here's what I did: I was installing stick-on white covers over the gauges, which called for removing the needles on the speedo and tach. The speedo needle was stubborn. Turned the needle assembly carefully counterclockwise slightly and pulled. After several tries I must have turned it too far and it let out a little "skweek." Eventually broke the needle assembly off its pedestal. Got everything back together, but now the speedo is off. It's fine through the lower speeds, but at higher speeds registers too high. When I'm going 55, for example, it shows 60; going 60 it shows 70.

 

um, thats not a simple linear error. if the needle is in the wrong place, the error will be the same at any speed (say, 55->60, 60->65, 65->70, etc).

at least on hte Yazaki 740/940 speedo I had to tweak on, you could reposition the needle relative to he mechanism by gently moving it all the way up to the stop (clockwise), then very carefully a touch farther til it 'sqicks' and jumps a few MPH. or, if you need to move it the other way, you CAREFULLY lift the needle over the stop pin, let it go to its natural stop (somewhere below 0MPH, and carefully force it to 'squick' in the counterclockwise direction. that stop pin is really fragile.

now, 240's typically have VDO speedos and I dunno if they are exactly the same.

 

I tried that. I When I very first reinstalled the odometer after I made the error, it was off by about 7 mph. So I removed it, turned the needle clockwise to the stop and "squiked' it what felt like a few mph. Because I broke the needle off at the pedestal it sits on, I can't use the needle to "squik", I have to use pliers, then allow the pedestal to spin back, then use double-sided tape to attach the needle at 0. Through trial and error, I found that by setting the needle at 10mph the speedo will be accurate through 50mph (but doesn't register the first 10mph, which I could live with). Then it goes haywire above 50-ish. Think it's possible to keep trying and get it adjusted or have I permanently broken something?

 

sounds like something is fubar.

time to hunt pick-n-pulls for a new instrument cluster me thinks. I don't know what years the 93 240 can take. (googles) ... hmm, maybe 1986+ are the same speedos? that would be nice. 740/940's have a bunch that aren't interchangable :-/

ah, ABS and non-ABS are different. one will read 5 MPH when the other reads 22 MPH, heh.

 

Sounds like the speedo is pretty messed up. Behaving in the way it is, I'd think there is a problem in the chip. If you are comfortable with a soldering iron, it's not a hard job, and pretty cheap. But it is by no means a sure thing. I was lucky--it was when I had speedo problems. Pick and pull would be a good idea otherwise.

As to setting your odometer, the mileage on the odometer can be changed--the only thing they have is that it will only go one way. So if you get an odometer with higher mileage, you have to flip it over. (there may be other ways, I've never done them) I have done it by hand by just turning the smallest unit until I added the couple thousand miles I needed. I recommend reading a book if that is your method.

My brother did it using a drill and a wheel of some sort attached to it, and did it much more rapidly. I was too concerned about the fragility of my speedometer. He was also doing it on a 700 series car.

 

Thanks for the help, guys. I bit the bullet and found a used cluster/speedo. Works fine. The odometer on the replacement has 8,000 more miles than my original, which isn't too bad. I can live with it if I can't roll it back or swap the tumbler cylinders (Lev, if you read this, got any hints on how to do that?). I know a couple of guys here with Volvo shops, so I'll see if one of them can help. Thanks again.