1979 Beetle - Speedometer Cable Problem

[dtrumbo]

Hi all,

Not sure where to post this question, so I plopped it here. On my '79 bug, the speedometer "bounces". I removed the speedometer, put it on the bench and attached a new upper (short) cable to it, ran it with my drill motor and it's smooth as silk. I then attached my new lower (long) cable, ran it with the drill motor and again, smooth as silk. I even put the EGR box back in the middle of the two new cables and it's still smooth. O.k. to find the smoking gun, I removed the old upper cable, ran it, still smooth. Then I removed the lower cable, ran it, AH HA! There's the bad cable. Fine, I put both new cables in the car, drove it and the bounce is as bad or maybe even worse than ever. AAAARRRGGHH!! So this morning, I sprayed graphite lubricant in the new cables until it dripped out the other end and it made no difference.

In the bug, the cable attaches to the back of the speedo at a "right angle" which means it has to make a pretty sharp bend from where it comes through from the trunk to get into the speedo. Could this bend be putting "side load" on the mechanism internal to the speedo? If that's the case, how does one go about resolving this. It's one of those things that will drive me nuts, which is my own fault, but I know at some point it used to work properly and I'd like to get it fixed. Any suggestions?

[Amskeptic]

Hi all,

Not sure where to post this question, so I plopped it here. On my '79 bug, the speedometer "bounces". I removed the speedometer, put it on the bench and attached a new upper (short) cable to it, ran it with my drill motor and it's smooth as silk. I then attached my new lower (long) cable, ran it with the drill motor and again, smooth as silk. I even put the EGR box back in the middle of the two new cables and it's still smooth. O.k. to find the smoking gun, I removed the old upper cable, ran it, still smooth. Then I removed the lower cable, ran it, AH HA! There's the bad cable. Fine, I put both new cables in the car, drove it and the bounce is as bad or maybe even worse than ever. AAAARRRGGHH!! So this morning, I sprayed graphite lubricant in the new cables until it dripped out the other end and it made no difference.

In the bug, the cable attaches to the back of the speedo at a "right angle" which means it has to make a pretty sharp bend from where it comes through from the trunk to get into the speedo. Could this bend be putting "side load" on the mechanism internal to the speedo? If that's the case, how does one go about resolving this. It's one of those things that will drive me nuts, which is my own fault, but I know at some point it used to work properly and I'd like to get it fixed. Any suggestions?

Strangely enough, the cables like a slight resistance up near the speedometer head. The wiggling needle is minor torsional variations in the cable's twist. Try plastic wire tie near speedo (2'' or so) to make cable do a slight bend or mild kink. It is like an axial shock absorber. Also, check that the cable does not protrude too far into the speedo. Sometimes they stretch over their lifetime and push into the speedo. You can test by loosening the knurled nut at the end of the speedo cable and putting a rubber o-ring that fits on the inside of the knurled nut without getting in the way of anything, attach to speedo and test drive.
Colin

[dtrumbo]

O.k. so I tried all of that with the new short cable and had some success, but very minimal. I then reinstalled the original VDO, made-in-Germany, real-metal-locking-ring, original-VW-trunk-wall-grommet cable and what do you know? It works just fine. This is with my drill motor acting as the left front wheel, I haven't actually road tested it yet, but I'm confident it will work fine.

This is where Colin gets to rant about the after-market crap that we're sold these days. The cable is nice, says "Made In Germany" right on it, has a very nice grommet that goes through the trunk wall, but that might actually be the problem. The grommet is this huge stiff thing with a sleeve that travels down the length of the cable about an inch and half. It looks like it would "support" the cable nicely, but what it doesn't do is allow the cable to pass through the trunk wall at an ANGLE. The angle allows it to engage the speedometer at a much shallower bend which appears to be the trick to getting it to run smooth.

You'd think I'd learn. My old '85 Chevy pickup had a jumpy speedo so I replaced the cable with one from my FLAPS. It was even worse. I then bought a cable from the dealer (yes, three times the price and it had to be ordered), smooth as silk. Since everything seems to be working now, I haven't checked, but I wonder if you can still get Genuine VW (VDO) cables from the dealer?

Thanks for you help Colin, can't wait to meet you next month!

[karl]

I haven't checked, but I wonder if you can still get Genuine VW (VDO) cables from the dealer?

The bad thing about ETKA, the VW parts system, is that once a part becomes NLA then the part number vaporizes. The upper cable has been discontinued so the VW part number vaporized.

The lower cable part number was 133 957 809 A but it is NLA from VW.

The one piece cable, doing away with the EGR counter, was part number 113 957 801 A but it also is NLA from VW.

Those 2 part numbers will vaporize in the next release of ETKA. The upper was NLA before the release of my version of ETKA..... that is why the number has vaporized.

But the afternarket companies, like IMC, still use the VW numbers. That is why Bus Depot can sell you this one: http://www.busdepot.com/details.jsp?par ... 113957801A
But it is not a VW part.

[dtrumbo]

Thanks for checking, Karl!