Speedo Reset Button (and some other stuff)

[Luca]

fbenach, rom what I can gather, the boot goes over the button, but is sandwiched between the plastic collar and the glass.  This means that you need to remove the bezel (I ground a paint can opened down a bit and gently pried away) and glass, but no further gauge disassembly is required other than removing the nut from the back of the collar to get the new boot under it.

I think Bobs BMW and Hendersen Precision have the plastic collar incase that breaks.

wirespokes, thanks for the idea about the vinegar.  I was worried about damaging plastics, but vinegar should work just fine.  If I go with stainless, I'd probably ask my brother to just grab a couple chunks of stock from the scrap bin at his job.  I should at least be able to get you the dimensions so you could search the internet or take it to a machinist.  Who knows, maybe my brother can make you a batch.

Ill keep you posted.  Got distracted today by somebody's new-to-him SV650S.  I've started playing mechanic.

[tvrla]

I've managed to replace the reset cover without removing the lens. Did it from the outside. But I wouldn't guarantee it will work. You'll need to unscrew the collar a ways to enable replacing the cover, and then screwing it back down. Not exactly easy or guaranteed to work when the retaining nut is on the inside.  

The reset cover actually extends down into the hole.

If the retainer/collar is damaged, replace it! They tend to break, at which point the cover takes a hike. Metal retainers are preferable.

I think it was in the late 80s the lenses changed to plastic. Is that what you're talking about? I wouldn't think an R65 would have a plastic lens.

[Luca]

No, I meant the plastic wheels.  I was gonne try some penetrating oil on the shafts, but wasn't sure about how it would work in the long run.

I thought the collar was plastic too.  Didn't really check though.

Quite happy that my lens is made of glass  [smiley=bmw_smiley.gif]

[tvrla]

The collars are plastic from the factory. Check it to make sure the flange isn't dished. If it is, replace it!

What about the plastic gears? You're speaking about the white helical ones on the input shaft - the ones that convert the angular input to the speedo head?

[fbenach]

Thanks Luca and Wirespokes, sounds pretty simple, I´ll give it a try!!

I think my lens is plastic actually, I should check on that...

Take care!!

[Luca]

I meant the plastic intermediate gears on the trip meter.  The ones that roll the next (greater) digit over every time the lower digit reaches 10 (0 again).

It seems that there are several problems with my trip/odo meter at the same time.  The plastic spacer on the odo has slipped on the shaft, letting everything wiggle freely.  Only damage was some minor galling of the teeth on the odometer intermediate gears.  I've filed em a bit and that seems to have smoothed things out.  Perhaps I'll give it a bit more before final assembly.  Instead of gluing the spacer back in place, I plan on either knurling the shaft to hold the spacer or shimming it with small e-clips.  It can spin freely as long as it keeps the gears sandwiched together.  I don't trust super glue anyways.  Did the knurling trick on my old Mercedes Diesel odo and it worked great.

Additionally, the corrosion on the trip meter shaft froze the intermediate gears (not wheels).  Because the trip meter and odo are mechanically linked, this seizure caused the worm gears driving the whole thing to start spinning on their shafts.  

The corrosion also ate apart the trip meter reset button spring and crudded up some other metal bits in the bottom of the gauge.

Sorry if my terminology is poor.  I plan to put together some sort of article showing the guts and how they work as I re-assemble the gauge.  Working on getting a new trip meter intermediate gear shaft.  Won't be able to turn things on the lathe.  Got an assorted package of "musical wire" from the big box hardware store.  If that doesn't work I'll probly have to go with the internet or an industrial supplier (msc, granger, etc.)  Seems that the rods are 1.5 and 2mm, but I took pretty rough measurements.  I'll confirm what works when I find it.

Also, thanks for the suggestion on the reset button collar.  Mine is slightly dished.  Ended up getting the parts from Bobs BMW as they sell the boot and collar together.  Vinegar was also very helpful in removing rust.  I did use penetrating oil on the metal shafts because it was necessary.  Plastic seems fine.

Thanks again.
Hope to have a conclusion soon.

[tvrla]

That's what happens when the reset cover goes bad and lets water inside. Not pretty!

I used to knurl the shaft where the odo gear slipped. Usually that worked, but a few times it didn't. Some guys have JBWelded the gear to the shaft, and some of those have slipped. I pin that gear to the shaft which handles that problem terminatedly.

Vinegar is great stuff, huh? I use it all the time for derusting things.

[Luca]

I plan to have a full report for everyone here, but for now here is a brief moment of good news.

I've got the meter back together.  Gel pen provided the new reset button spring.  Got plain steel rod from the hobby shop.  SS was too hard to find, and very expensive from the big industrial suppliers.  Might be able to get it as RC car or plane parts... but when in a rush you do what you can.

Rather than peen the rods over at the end, I just cut them long.  The trip intermediate gear shaft is held captive by the trip meter housing, so it can't fall out.  I cut the intermediate gear holder/reset finger thingy (I'LL HAVE PICTURES!) shaft at 3 inches and the trip meter number wheel shaft at about 3 1/2 inches.  Once installed in the meter housing, those shafts can't slip out at that length because they would hit the walls of the housing... and no hammers got anywhere near my sensitive instrument.  I gently rounded the ends of the shafts on the bench grinder.

I used 5/32 (3.9mm) e clips to shim the odometer spacer wheel.  Everything moves freely, but the gears can no longer disengage.  I like the pinning idea, but this way I didn't have to remove the thing and do delicate drilling.

My $2700 HP paperweight (3 year lifespan laptop... but that belongs in "rants and raves") provided me with the properly threaded metric screws.  They're silver philips with a sort of flat topped pan head...  Only an airhead would notice, and it's kind of fun leaving a subtle change like that.

Vinegar was safe to clean the gauge face with.  You get a small inconspicuous area to test cleaners around the hole for the speedo needle shaft.

Bench tested the speedo with a cordless drill on a fresh battery.  Corded would work, but not a drill press since the speedo cable rotates counter-clockwise.  Seems to be pretty darn close 1.05 miles at 62.5mph for one minute.  Almost seems better than the cautionary stock calibration I've heard about.

Now if I can just remember which rubber seal goes where on the glass and bezel I can have this thing stuck back together tomorrow morning...

[tvrla]

I don't have a neat way of crimping the odometer shafts either. I leave one end mashed(don't change that), and put a blob of solder on the other end once it's all together. Quick and easy, and easy to remove if I have to get back in there.

Spacing the odometer gears doesn't keep the main culprit from slipping on the shaft. That's the primary problem that needs to be taken care of.

[Luca]

The metal wheel on the right end of my odometer that drives the odo and trip meters was fine... no slippage.  The problem was that the number wheels could move left to right along the shaft, and as they did they could disengage the intermediate gears and do whatever they pleased.  Guffed up one of the intermediate gears in the process.  Shimming between the spacer wheel and metal housing remedied the problem.

I like the solder idea, but since I used new shafts, I just cut them long enough that it would be impossible for them to slip out.  Less work and more reliable IMO (though the BMW metal is probably of better quality)

I's all back together and been good for 200 miles, including some exposure to heavy rain.  I've got some pics and started putting a little article together... just haven't had the time to get it done and post.

[tvrla]

There's a reason you had all sorts of play between the number wheels and it's not because it came that way from the factory. It's because that pot metal gear slid to the side.

Shimming the shaft will prevent the number wheels going out of registration, but then again, watch for the time you go on a 200 mile ride and only register fifty. If it slipped before, it will again! All of them do sooner or later.