Speedometer Disassembly??

[panteradave]

I have recently purchased a 150mph speedometer to replace the 85mph version on my '82 CBX. I'm currently rolling the mileage back on the replacement using an electric drill to match the actual miles on the bike. I'm estimating it will take a couple of days to subtract off the extra 7500 miles.

While I'm waiting, I've noticed that the inside of the lense has a minor water mark that while is not obvious, does distract from the overall look of the speedo. To clean the inside of the lense obviously requires disassembling the speedo housing. A quick examination suggests that the front bezel needs to come off but it looks like it is crimped on over the lip on the plastic housing.

So my question is - is this doable by a normal mechanically savy mortal without serious risk of bending the bezel beyond repair? If so could someone provide a little advice/instruction of how to accomplish this safely?

Also, what is the trick from removing the trip meter knob? The knob appears to be threaded on the inside and mates to a male threaded shaft on the speedo, but turning the knob just rolls the trip meter digits. Maybe some needle nose pliers past the rubber grommet to hold the shaft while turning the knob?

Any adice would be greatly appreciated.

[NobleHops]

Dave, the tripmeter is either held with a set screw or reverse threaded. If you don't see a set screw try screwing it clockwise to remove. I'm sure there are threads discussing the opening of the gauge, but in short you're on to it, that's what has to be done.

EDIT: Do a search for <speedometer> and you will find dozens of threads discussing any and all aspects of repairing these.

N.

[Jeff Bennetts]

This isn't a CBX gauge but works the same way, some people use a thin blade screwdriver but I would try using a hose clamp about 1/2 inch below the bezel and then use a pair of wide duck billed snap ring pliers to pop them off. Use the pliers between the clamp part of the hose clamp and the bezel.

This should help along with the other threads, while your in there why don't you just reset the milage by resetting the number tumblers?

[panteradave]

Thanks for posting the photos. They really help as far as seeing how the speedometer disassembly goes. I was planning to drill a 4" hole in a piece of 1X6 to protect the bezel but the big hose clamp should work just as well. I was able to remove the trip meter knob by turning it clockwise as recommended so am about ready to start pulling the speedo apart.

To roll the odometer digits back (other than by hooking up a drill running in reverse, which I've calculated will take at least 3 more days) - does that require taking the odometer mechanism apart or is it merely spreading the digit wheels far enough with maybe a small screwdriver that the gear teeth disengage?

Thanks for the help and ideas.

[Jeff Bennetts]

Thanks for posting the photos. They really help as far as seeing how the speedometer disassembly goes. I was planning to drill a 4" hole in a piece of 1X6 to protect the bezel but the big hose clamp should work just as well. I was able to remove the trip meter knob by turning it clockwise as recommended so am about ready to start pulling the speedo apart.

To roll the odometer digits back (other than by hooking up a drill running in reverse, which I've calculated will take at least 3 more days) - does that require taking the odometer mechanism apart or is it merely spreading the digit wheels far enough with maybe a small screwdriver that the gear teeth disengage?

Thanks for the help and ideas.

It has to come apart, not for the faint of heart but it can be done. I had my dining room table under siege for a couple days, the wife wasn't to happy with me.