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Speedometer/Tachometer, an Open & Shut Case

Posted: Sat May 26, 2012 2:49 am
by Roady
The speedometer on my bike has been flaky since day 1. On the best days it would wave around slightly, varying 5 up or down. I knew that I was going along somewhere in the middle. On bad days (and days, weeks ...) it would peg at the top and scream bloody murder. Ear plugs helped but the noise managed to get past even the best ones I had. Plus, when turning, the darn yelping beeper would always be on. Removing the cable was the only way to get away from the noise. But then I wasn't tracking miles on the odometer, which always worked fine.

Years ago I received a broken speedometer from Brant, thinking at the time that I'd use its parts to repair mine. I opened that one by prying the ring and that worked out pretty good. But at the time, mine started acting okay and I boxed up the mishmash of parts for another day.

I finally decided today was the day to open the thing up and fix it. And I didn't want to cut the ring and then try to figure out the best way to seal it back up. Here's how I did it.

Opening a GL1100 Speedometer or Tachometer

This is similar on all analog gauges.

On the GL1100 speedometer (and tach, I assume), there's a small cutout in the back case's lip. Back being the one toward the front of the bike ... with the cable mount and wires sticking out. (Oh man, now I'm confusing myself. :roll: How about a picture?)

If your ring is clean all the way around, that cutout is as good a place to start as any. If your ring is discolored or rusty that's where you want to work. You'll be prying up about half the way 'round and then you'll hide that area down and to the inside.

1start.jpg

I have a large collection of dental tools in the toolbox. They are very strong and have various tip shapes. Pretty handy things that I picked up at a swap meet for cheap. You might use a utility knife (careful) or a pocket knife for this step.

2tools.jpg

Work your tool back and forth to open a small gap.

3pry.jpg

Just pry the ring up enough to be able to slip in a small screwdriver.

4pry.jpg

With the screwdriver just catching the tip, press in and then down on the handle. Do not twist the screwdriver, you'll make major dents and may even tear the ring. Work the ring up a bit and move the screwdriver 1/16 inch sideways. Then press in and down on the handle a bit. Do that for 1/2 inch or so and then work back over the same area lifting the edge of the ring a little more.

5indown.jpg

Continue the in and down action until you lifted half way around the ring. Take your time, take a break, smoke 'em if you got 'em.

6indown.jpg

When half of the ring has been bent up you're ready to pop that baby out. At the half way point of your bent-up area, slip your screwdriver under the ring and over the case -AND- the rubber sealing ring. Try not to gouge into the rubber.

Lift the screwdriver up this time and the rear case should start slipping out from under the ring. But don't push up so hard that you bend the ring any more than it already is. You might have to move around and pry up in your bent-up area. Be patient and it'll come free.

7inup.jpg

Remove the two Phillips head screws.

8phillips.jpg

Open up the wire ties.

9stays.jpg

Separate the case. The ring will stay on the front case (the one with the glass).

The GL1100 trip meter knob will slip through the hole in the case, but you will have to tear the boot away. Mine was already torn away so I didn't worry about it much. I just glued it back in when reassembling. I've seen notes about some Honda speedos that say the knob is reverse threaded. Turn it clockwise to remove it. I tried holding the stem with needlenose pliers and turning the knob but it would not come free ... your results may vary.

If you got it apart okay, putting it back together is a breeze. Put the gauge into the front case and thread the wires back through their holes in the back case.

Thread the two Phillips screws in but do not tighten them down.

Slip the un-crimped section of the ring back over the back case. This takes a bit of doin' but you'll get it on there. Tighten the Phillips screws. Center the trip shaft in its hole.

For the next step, I picked my biggest (and oldest) pair of pliers to put the ring back on. To protect the ring from scratches, cover the tips of the pliers with duct tape, cloth or something. I used masking tape which wasn't quite up to the job so I had to watch it and replace as needed.

With the bottom jaw of the pliers, press in and up on the ring on the front case. Then gently roll up the bent-up part of the ring. You don't want to clamp the pliers down, you want to roll the edge of the ring in. Start at one end of the bent part and work around, gradually moving the edge back into its place.

10pliers.jpg

Opening my case took about an hour and closing it up took about half an hour.

Now, put it back on the bike and go for a ride already!

(I swapped parts from two speedos and did a little light lubing with White Lithium Grease while I was in there. On the broken one, I tried to remove the needle to see how I'd put on new faces, not that I needed them but just to experiment. I broke off the needle, don't know how you'd get it off or how you'd get it back on in the correct position. If replacing the face, I'd cut a slit or two in the middle and slip it over the needle, then just glue those cuts down.)

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sat May 26, 2012 2:54 am
by fish
Roady thank for taking the time to photograph and write this
sounds like finesse and patience are the key :mrgreen:

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sat May 26, 2012 7:30 am
by Oldewing
Nice work Steve, glad to see you found your yellow pointing thingys...

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sat May 26, 2012 1:32 pm
by Placerville
Nice job on both the description and photos. action1

I agree, 'prying up' is the best all-around method. I tried both 'the cut' and 'the pry' on some junk gauges I had.....the pry was cosmetically the best. As you said, patience is a virtue.

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sat May 26, 2012 2:03 pm
by polkadot
I Love Roady's Flying Fickle Finger of Fate! Great job Roadster. Did you clean and lube the inside? I would like to see that as my gauges are really working slowly!

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sat May 26, 2012 2:10 pm
by Roady
Thanks fellas.

I did do a clean and light lube and will be adding to the first post.

In the past, I forced Lithium Grease up into the hole where the cable goes. That helped, on and off, for a time. But the inside was all goobered-up (a highly technical term, look it up), especially around the bell and magnets. That was probably not a good idea.

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sun May 27, 2012 12:42 am
by Old Fogey
I've seen notes about some Honda speedos that say the knob is reverse threaded. Turn it clockwise to remove it. I tried holding the stem with needlenose pliers and turning the knob but it would not come free ... your results may vary.


That is correct, but the later speedos had the knob fixed with some sort of thread lock. Trust me, these will NOT come off!

I tried to remove the needle to see how I'd put on new faces, not that I needed them but just to experiment. I broke off the needle, don't know how you'd get it off or how you'd get it back on in the correct position.


First turn the needle to a speed that you will remember and mark the frame and driven cone with a felt pen.
To remove the needle, use two teaspoons, one on each side of it with the bowl resting in the two face screws and the tips under the needle. Lever gently and it will come off.

In the past, I forced Lithium Grease up into the hole where the cable goes. That helped, on and off, for a time. But the inside was all goobered-up (a highly technical term, look it up), especially around the bell and magnets. That was probably not a good idea.


Oil and/or grease getting between the bell and the magnet will cause erratic readings. If the problem is the cable lube, use graphite powder. If it’s the speedo itself, once it’s opened up a tiny drop of light machine oil on the needle spindle will suffice for that ; there is also an oylite bush in the threaded potion of the drive which needs oiling too.

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sun May 27, 2012 7:55 am
by Roady
Thank you John. I'll include your notes in the OP.

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sun May 27, 2012 12:38 pm
by rogue1000
Thanks Roady, I've been contemplating doing mine because it is so slow, but I checked it two weeks ago with a gps and it surprised me by being accurate, so I'll just wait...nice to be armed with the knowledge of how to do it though... :-D

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sun May 27, 2012 1:30 pm
by sunnbobb
Nice job Steve. The pics are so good I feel like I was there!

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Fri Aug 17, 2012 2:52 am
by gltriker
tumb2

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Sun Feb 12, 2017 9:16 pm
by tlbranth
Hey Roady - where's the pictures?

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Mon Feb 13, 2017 10:40 am
by RAT
This was posted 10 years ago and our site has undergone a couple of updates that cost us some picture links.

Roady may have his 'originals' and will hopefully update when he next visits ....

Gord

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Mon Feb 13, 2017 11:51 am
by Whiskerfish
yea these were hosted somewhere besides NGW. Hopefully he has them backed up somewhere.

Re: Speedometer/Tachometer, an Open & Shut Case

Posted: Mon Feb 13, 2017 3:05 pm
by Roady
Yep, those are on filipi like most of my pics.

Hoping this doesn't mean I have to find and replace 'em all (been dreading that for a while).
.