Speedometer reset

[waco69bug]

This may be slightly off topic, but can anyone tell me how to "adjust" the speedometer for different sized tires. I've got slightly smaller tires on my bug and the speedometer is off. I'd like to fix this if possible.
Thanks.

[glutamodo]

You only have so many splines you can set that needle on, although you can pull the needle carrier off and reposition it as well, to alter the needle pretension, and thus, the speedometer accuracy, but that's going to be a try-and-see sort of process. Drill with a speedometer cable would help. You might not be able to get it exact either. Note that only the speedomer calibration would be changed, the odometer is a direct counter of wheel revolutions and will still be wrong with the wrong tire height.

[bill may]

[jsfocke]

First of all let me say that I am so glad I found this forum.

I did a quick search to find out why my odometer isn't working and found this thread. I understand that my plastic gear is probably broken. So, I dug in my boxes of old parts from another bug that I took every good part off of before I scrapped it and found my old speedometer. IT really looks good and the odometer works on it. But, after taking it apart to clean it out and put some new lubricant on the gears I found that it's gear is indeed cracked too. So, I went ahead and ordered a new gear.

It was very easy to take everything apart thanks to the visual instructions. I even set my old odometer to my current cars mileage in case I find other problems when I open up the current cars speedometer.

Hopefully I will be clicking off miles so I can check my MPGs in a week or so.

[joemac]

For those who don't want to spring the $$ for a new odo drive gear:
Slide the gear off the shaft. Insert it onto a small brad, one that is large enough to open up the crack. Place a very small drop of super glue into the crack, then remove the gear, placing it where it won't stick to anything. I like wax paper for this.
Take a bread tie (the little paper/plastic coated wire tie that comes on a bag of loaf of bread) and strip the wire off. You can use a ciggie lighter to burn it off in a few seconds, just don't burn down your garage.
Wrap the wire around the end of the gear, next to the teeth, and twist it tight with needle nosed pliers. Do both sides and tuck the ends away from the teeth. After allowing the super glue to fully cure, slide the gear back onto the shaft, after slightly scoring the steel shaft with small wire cutters, to provide a friction fit.

I've fixed dozens of odometers this way, including Porsches with the same plastic guaranteed-to-split gear. They've all held up well for years, including my 944 odo that only worked when the car was cold!

[jbaakko]

Thanks guys, that fix worked, sort of.

I recently bought a '71 STD Bug (111), I must state I pretty much know nothing about beetles. I did not notice when test driving the car that the speedo was not working.

Well anyways, I discovered the magnet was frozen by a thick layer of grease. The Speedometer works now, well, sort of.

Looks like the frozen magnet, froze the cable, in turn rounding out the grease cap.

So, I'm going to order a new cable and grease cap, hopefully I'll have a working speedometer then!

[jbaakko]

Huh, Well, the Odometer works with the new cable/grease cap... Not the Speedometer still does not.

I've double, triple, and quadruple checked the gauge... Is there anything between the magnet & dial that can bind that I might be missing, that would keep the dial from moving?

I can manually turn the dial, when the magnet is removed, and with some force, move it when I re-install the magnet portion. Is this a sign that the magnet-to-dial portion is out of alignment somehow?
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Josh

[glutamodo]

Well, with the magnet removed there still are like, two other bushings that support the shaft the needle fits on. Sounds like one of those is bound up. This is a photo of a mid 60s speedometer pointing out those other two bushings:

[Shino166]

Hi, I'm new and arrived at this thread by fate I have a 79 beetle and my speedo makes a clicking sound when ever I move, I think its my gear that's split, find out when I take it apart.

The thing that has me puzzled is that my speedo always indicates speed with a very large error, say my speedo reads 60 km/h (my speedo is in km) I'm actually going at 40 km/h, I tested it with a friends car driving beside me. Could it be the pretension of the needle spring. Appreciate the help, the more info I have before I start taking things apart the better

[buddy boy]

do you have smaller tires?
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DVKK Member (Der Volksrennwagen Kafer Klub)

[Shino166]

my tyres are 185/65/15...should be no prob right?

[glutamodo]

Those tires are a bit smaller in diameter than stock, so will introduce some variance, but not on the order your are seeing. Does your speedometer needle "bounce" ever? If the gap between the magnet and the cup that fits around it has decresed from when it was new, like if the bushings have worn, then it'll pull the needle assembly around harder than it's suppposed to and that will result in the speedometer reading too fast. And then, it could be the needle pretension is off (spring may have lost some oomph)

[Shino166]

yeah it does bounce a little now that you mention. I'll check what you said and post how it goes

[thumpbug]

Thank you so very much for your time and effort to share your knowledge with us. I'm doing a custom resto on a 72 beetle and will want to reset the speedo. I searched for the info and POW, here is everything I needed to know and so clearly explained.
Again, thank you, you're awesome.

[1 THING]

[donmurray]

74 Ghia speedometer worked, but odometer & tripmeter did not. I have the speedo removed and out of its case. Turn it with a drill & a sharp round stick, and now everything seems to work?? The long worm gear teeth are ok, and the brass gear and shaft turn. Brass gear seems tight on the shaft. All shafts, wheels, and cogs are free (I can wiggle them a little with a small screwdriver). Any suggestions as to what had the odometer stopped, but now is OK? What about the larger gear that engages the tripmeter? With a little pressure from a screwdriver, I can turn this gear and the small brass gear does not move. I can imagine that if many of the odometer and tripmeter number wheels need to move at a certain mileage, the resistance might be enough to make the larger gear slip. Is this a common problem? On my unit it looks like the needle and face will have to be removed before this shaft and number wheels can be removed. Not a very appealing task, so may be better to take it to a speedo repair shop.

[glutamodo]

74 Ghia... that's the type 4 style speedometer. I've never torn one of those apart before so I can't really advise you on this one.

[donmurray]

Today I decided to attempt the speedo repair myself. Face came off with some tedious prying all around. A small screwdriver with a bent tip worked fine. Inside, the 74 Ghia speedo does look different than any of the pics in this thread. Maybe a little heavier stronger castings that holds all the parts, and a trip meter.

Moved the needle off the stop post and marked where it was pointing so it could go back in the same position. Put a towel in my lap/between legs, so I could hold it without damaging anything. With some thin paper board to protect the face, got a firm grip on 2 spoons, making sure the points were against the center, and the needle popped off. Two tiny screws and the face was off giving me access to the odo wheels.

A strip of masking tape on the plastic number wheels to keep them together. Removed the shaft holding the plastic number wheels and the large metal wheel next to them. This shaft came out pretty easy by prying under the brass gear. It came out easy because the only thing holding it in is the press fit in the large metal gear, and that's the part that's slipping. Did not remove the lower number wheels and gear that make up the trip meter.

I located the spot on this shaft where the gear goes and put some knurls on the shaft to make it grip the gear better. Did the knurl with needle nose vice grips. Gripped the shaft then clamped the end of the pliers in a vise. You can't do very much knurl because the shaft has to go back through the hole on the brass gear side and through the plastic number wheels. You don't want to drive a knurled shaft hard through this hole because it'a a bearing surface for the shaft. I did a little too much knurl, and it took a lot of tapping to get the knurled part back throught the big gear, but I'm sure it won't slip there again. It's important to only knurl the shaft where the gear goes. Any knurling outside that may bind the adjoining plastic number wheel, or where the shaft rotates in the frame. The needle nose vise grip was just the right width, but the corner of a wider plier might be narrow enough.

The little plastic cogs that trip each wheel have to be lined up the same. They have alternating teeth types. Also have to be careful to keep them properly engage with the plastic wheel teeth as you drive the shaft back in. A closeup photo will help get them back right.

Did a little clean up on numbers with a dry cotton cloth. Used a toothpick to put some light silicone grease on the worm gears and plastic teeth. A tiny bit of oil at metal points.

Noticed that all the screws that hold the 2 frame pieces together were very loose. That may have made a bind in the cogs and caused the big gear to start slipping.

Got the needle back on close the the original position. That part is a little scary because the needle looks easy to break, and the shaft is so skinny. Used a small piece of wood with a grove so the pressure was on the black round needle mount and not the needle itself. Started it with finger pressure, then tappen with a small wrench.

Tested that everything works by using a ponted round stick in a drill. Think it was a bamboo shish kebob stick.

Think I will paint the inside of the housing for better back lighting. Clean & lube the cable.
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74 Ghia, with 2110 engine

[busbum08]

Okay, I've never had to do any speedo work before but recently acquired a 68 bus thats having some issues in there. Everything is fine until I reach about 50, then it started increasing slower(had someone driving next to me to speed check), and the needle would not decrease properly either, would stay at 50 or 60 or whatever it was last at, even while not moving.
Pulled the speedo out and can feel as I manually turn the needle that it gets "sticky" past 50 and actually feels like there is a little notch that the needle can sit in at 60, and is "sticky" up to 75 on the face, then moves freely after that.
HOWEVER, if I gently pull the needle away from the face(there is a little play back and forth in the needle) while I am turning the it, it moves freely throughout the entire range and does not get held up anywhere.
Any suggestions?
Thanks
Dan

[PaRacer]

Thanks to glutamodo's excellent instrucions & pics, I got around to working on a speedo I bought here on Samba to replace the one on my '73 standard. All went well until I tried cleaning the black face & white numbers. I tested some Simple Green on the fuel gauge first and it worked great. The white letters on the speedo face started to run when the Simple Green hit them! I was able to daub it off and get it cleaned up without much damage. I just wiped off the rest of the speedo face with a soft cloth and called it good! The needles were not nice and white so I touched them up carefully with alittle white paint. It looks great and I was able to roll the odometer back to 1000, the mileage on my bug since restoration. My color cells were still good, I just cleaned them and the lights up good. Thanks for the great tips, I probably would not have tried this on my own without them.
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'73 Standard "Sunshine"