Speedometer reset

[67rustavenger]

[houseofboyd]

[glutamodo]

[Coskier]

Looking for help here.
As I'm driving my '66 Ghia down the road, everything is great... then a horrible screeching noise kicks in. It stops when the car stops.

A mechanic said it that it was the cable between the speedo and the wheels.

My question... do you think the speedo needs to be replaced also, or just the cable?

Thank you!

['69Custom]

Admittedly, I have no experience with late model Bus speedometers but I have encountered issues like you describe from time to time. As you noticed, the needle shaft has some "in/out" play. Occasionally, a slight jarring or even a funky manipulation of the speedometer can cause that shaft to get sunk "in" and bind up just a bit. It's only enough for the shaft to not want to spin freely of its own accord like it should. Basically, it increases friction and resistance. What you did popped it back out.

At most, what I have done after popping it free is to add a single small drop of lubticating oil to where to the base of the shaft where it gets caught up. Solved the issue every time. Be sure to work the oil in by spinning that needle around before reassembly.
_________________
-Tim

1969 Frankenbug
1965 Ford Mustang
:2gunfire: F-U-M-P!
~"I thought I was wrong once, but I was mistaken." ~The Boss
Please excuse any typos as my iPhone doesn't speak English very well. 

[Andy70Bus]

Hey folks,

I have a 1970 Bus and it has the original speedo in it. I found this thread and the other big one and after reading them through, decided to try and fix mine.

Background: Recently, my ignition switch went bad so I had to replace it, meaning basically removing the whole steering column from the bus. While I had that disassembled and waited for parts, my instrument cluster was removed and sitting upside-down on the dash. It was sunny, but cool - the bus was stuck in the driveway since it had no ignition switch. So, I don't think the speedo was overly baked.

Once I had everything put back together, I took him out for a spin and the speedo initially seemed to be not working, but then it jumped up in a few bounds and eventually all the way back to the stop, as if I was doing 100+ mph (I didn't exceed 40 or so). Upon stopping, the needle did not return to zero. I watched to be sure and yes, the odometer was working fine so I was sure the cable was spinning properly.

So, I took the instrument cluster back out. On the '70 Bus, the speedo and the other gauges all share a single backing plate and bezel set, so there was no chrome ring to pry off - take off the back plate and the 2 screws holding the speedo to it, and carefully remove the whole speedo.

With the unit out of the cluster, I could move the needle to any position on the face and it would just stay there - no springiness at all. So I was assuming that the spring was broke or loose or something...

Next step: remove the needle. I cut a hole in the side of a sturdy little cardboard box to hold the speedo assembly upright, then tried the "2-spoons method" outlined here to pull off the needle. Nothing doing, no movement at all - I'm not sure this is the way to remove my needle on this type of speedo.

BUT, I noticed as I was trying to pry up the needle, that it seems to be moving back on it's own, so I removed the protective paper I had under the spoons, and voila, the needle springs freely and easily back to zero... If I move it up, it pops right back - smooth, free, easy, no binding...

By lifting up on the needle and thereby the shaft, I must have dislodged a little particle or bit of grease that was binding it up.

What would ya'll do now in my position?? Just put it back and be happy, or should I use a little brake cleaner in there and then some grease - I don't want to tear it apart any further if there is no need.

Thanks,
Andy

['69Custom]

[Little-Acorn]

Glutamodo, thank you! That looks a LOT like my speedo. I'll go through that link, and try to get this one apart.

[Little-Acorn]

Looking at this speedo, brings to mind a story I heard about Germany vs. Russia in WWII. Germans had the Tiger tank, which everybody said was a beautiful example of precision engineering. No one doubted it was a really good tank. The Russians had a new one called the KV. Big tank, big gun, heavy armor, but somewhat crude and clunky.

But the problem was, the German Tiger took a zillion man-hours of skilled assembly and fabrication to produce. The Russian KV could be thrown together (most of it) in maybe a quarter of the time, by people used to shoeing horses and mending farm tractors. So the Russians were able to produce a lot more KVs than the Germans could make Tigers, with the same amount of time and effort.

One comparison made between the two was, the Tiger's speedometer had 168 precision-machined parts that had to be assembled by a craftsman such as a watchmaker (this VW speedo reminds me of that). The Russian KV didn't have a speedometer at all - it had a green light to show you were moving forward, and a red light for moving backward. If you wanted to know how fast, look out the driver's optical slot and listen to the engine.

The Germans had been producing Tigers for a couple years before they invaded Russia, and had a good number of them. The Russians had barely started producing KVs, they had maybe half a dozen on June 22, 1940 when the Germans invaded. And then they had to move their production facilities back from cities near the front lines so the Germans couldn't bomb and/or capture them, which interrupted production for a while more.

But as the war wore on, the Russians overwhelmed the Germans with lots of tanks which, while crude, were just as battleworthy as the German tanks, and quicker and easier to fix when damaged.

This VW speedo reminds me of that precision craftsmanship I'd heard about with German technology.

[glutamodo]

Did you see the link I put in to a complete dismantle?

(yes, it is an earlier speedometer...)

http://www.thesamba.com/vw/forum/viewtopic.php?t=327535&

There should be no drag at all on the input driveshaft of the speedometer, but that shaft is also turning the worm gear for the odometer, and that might causing your issue.

WD-40 is not really a lubricant, by the way. There are many other products out there that work much better. I usually use Liquid-Wrench Non-Flammable or Tri-flow on speedometers - but yours sounds like it needs to come all the way apart.

From that other thread - this is a 1964 speedometer taken apart and the input shaft and worm gear shown:
'

_________________
Andy T.

"What is Glutamodo, Horror of Toyko, besides total, fiendish, quality-a-you brain!"

[Little-Acorn]

Wow, this is a GREAT thread. Thank you all for so much detail!

It covers every imaginable thing that can go wrong with a speedo... except for my problem.

I bought a 74 Super, and found the speedometer didn't work. That's the speed needle itself, and of course the odometer didn't turn either. Fuel gauge in the speedometer, worked pretty well, though.

Found that the speedometer cable was broken at the end that goes into the wheel. Got a new cable from Jbugs, but before I installed it I spun the (broken) end of the old cable with my fingers (other end still screwed into the speedometer). I could only turn it a half turn or so before it started tightening up, uh-oh.

Took the speedometer out of the car, and sure enough the tiny square receiver that the cable plugs into on the speedometer, was frozen up, won't turn even a little. I filed a nail down to a square cross section to mimic the square end of the cable that inserts into the speedometer. Slipped it in, and it won't turn at all.

Following the instructions in this thread, I took the speedo apart, prying loose the chrome ring and removing the ring, glass, and bezel.

Now I'm looking at the piece with the square hole that the speedo cable goes into (and that I slipped a square nail into). Sure enough, it wouldn't turn.

Took that drive mechanism off the rest of the speedo, and found that the cable turns a round magnet inside a little metal can. And the round magnet just wouldn't turn.

Long story short, I put a few drops of WD-40 on the shaft between the cable receiver and the round magnet, grabbed the magnet with my fingers, and turned hard. The magnet started turning slowly, and as I turned it and applied a little more WD-40, it started freeing up a little.

Sawed the head off that nail I had filed into a square, and used that in a DC drill to turn the shaft and the magnet. It now turns, but still has a noticeable amount of drag. I can see where that would put some stress on the speedometer cable, but maybe it's designed to have that stress? So the magnet won't whip back and forth or something? Pushing the magnet with my fingers, I'd guess it takes around 1/2 an inch-pound to move it. Maybe 6 to 8 inch-ounces, at a guess.

My question is, how much drag should that shaft and round magnet, have? Should it spin nice and freely? Or is "Still has some resistance" about right?

[houseofboyd]

[cb747]

awesome thread! my odometer doesn't work and was wondering how to get into it and how to fix it

[VolkDubz]

great thread, thanks for the info

[pwmcguire]

wow I purchased my brass gear with shipping for like 40 dollars 10 years ago. They are plastic but a lot cheaper,

http://www.odometergears.com

['69Custom]

[TexasAxMan]

On my '70 speedo, when I ease the needle past the peg it doesn't go to the mark, it floats around 1/4" to the left. I'm pretty sure someone has been into it before. Should I move the needle to line up with the mark?

['69Custom]

The removal of the front bezel is a tricky process. It isn't difficult, but getting it off without any damage can be. I say this only to prepare you that there's no guarantee you'll be successful. This bezel is simply chrome-plated brass so it's pretty flimsy and easy to damage. It scratches and tears easily. If your speedometer has been opened in the past it will be easier, but you're basically uncrimping that edge that secures it to the housing. Go slow and work it just a little at a time starting at one of the mounting ears.

Explaining it in any other detail is next to impossible. You just have to experience it and get a feel for it. And by doing so you'll understand what it takes to put it back on securely.
_________________
-Tim

1969 Frankenbug
1965 Ford Mustang
:2gunfire: F-U-M-P!
~"I thought I was wrong once, but I was mistaken." ~The Boss
Please excuse any typos as my iPhone doesn't speak English very well. 

[User]

Does the removal from the ring with the screw driver damage the case/ring? I may be incorrectly identifying the part... sorry! That part has me concerned.

How do you reattach undo this? Is it easy? Can we get more detail about the step after the reburb?

[darth brian]