Speedo only half working

[alexwolf1216]

A while back I replaced my angle drive and dust cap, but the speedo never gets above 35. I took everything apart and cleaned it again, but it goes right to 35 and stops. could I be missing something simple here?

[Jonathan]

Did it used to work, Alex?

If you told me you took the gauge apart too, I'd say maybe somehow the needle got put back on 180 degrees off and it's getting internally pegged or something. Not very likely though I'd think.

What's possibly happening is the new dust cap is slipping in the wheel at higher speeds. You can try to wrap some tape around the edge and stuff it back in there tighter. Use electrical tape if you'd like. Just something that makes it a little more snug and then doesn't spin within the wheel while you're moving.

Have a look at the backside of the dust cap too while it is off and check to see if the square hole for the angle drive cable end is still square and not now round.

[alexwolf1216]

It never worked since I got the car. I did have to take it apart to do the trip reset repair...and I did take the needle off, but I marked it with tape and put it back where it was.

Ill try the tape trick, maybe its that easy.

[Jonathan]

Ok. The never worked so far part is interesting. Makes me think it might be something related to the gauge and not only the dust cap or angle drive.

So it consistently reaches 35 mph and not above? Does any of that matter what speed you're actually driving? Like have you confirmed your speed with a GPS at the same time to figure out if up to 35 mph it is working correctly? That might be important for narrowing it down.

When they slip at the dust cap, then tend to do some erratic things at the needle. If it stays pretty solid at 35 mph while you are going faster than that, or say between 40 mph and 60 mph on the highway or something and it still stays at 35 mph, it might be some physical interference in the gauge.

Anything else non-stock on your car that's tied into that system like a cruise control perhaps? Any changes to the service counter underneath or the type of speedo cables on your car? Might be something is not turning at the right ratio for whatever reason.

[alexwolf1216]

Ok. The never worked so far part is interesting. Makes me think it might be something related to the gauge and not only the dust cap or angle drive.

So it consistently reaches 35 mph and not above? Does any of that matter what speed you're actually driving? Like have you confirmed your speed with a GPS at the same time to figure out if up to 35 mph it is working correctly? That might be important for narrowing it down.

When they slip at the dust cap, then tend to do some erratic things at the needle. If it stays pretty solid at 35 mph while you are going faster than that, or say between 40 mph and 60 mph on the highway or something and it still stays at 35 mph, it might be some physical interference in the gauge.

Anything else non-stock on your car that's tied into that system like a cruise control perhaps? Any changes to the service counter underneath or the type of speedo cables on your car? Might be something is not turning at the right ratio for whatever reason.

So it starts at 0 and moves up to 35, but slowly. I havent tried the GPS trick, but im sure its off the entire way. When it says 10mph. I am certain im likely going 20 or so. I also never thought to check the angle drive before I replaced it, but it wasnt working at all. At least now SOMETHING is happening.

No, no cruise or anything. I dont see any changes to the counter box. I replaced the lower speedo cable when I replaced the angle drive, so that leaves the upper as stock.

[Jonathan]

So it starts at 0 and moves up to 35, but slowly. I havent tried the GPS trick, but im sure its off the entire way. When it says 10mph. I am certain im likely going 20 or so. I also never thought to check the angle drive before I replaced it, but it wasnt working at all. At least now SOMETHING is happening.

No, no cruise or anything. I dont see any changes to the counter box. I replaced the lower speedo cable when I replaced the angle drive, so that leaves the upper as stock.

Gotcha. The part about it moving from 0 to 35 mph "slowly" says to me it is likely the slipping dust cap thing. Try the tape around the outside edge of the cap and then reinstall it so that you get the feel it is more snug and won't slip. It won't be some grand thickness of tape you'll need, maybe just one pass of tape or two. You'll see quickly the cap get more firmly in place. Ensure the square end of the cable is still getting centred in the square hole when you put it back on.

[alexwolf1216]

Gotcha. The part about it moving from 0 to 35 mph "slowly" says to me it is likely the slipping dust cap thing. Try the tape around the outside edge of the cap and then reinstall it so that you get the feel it is more snug and won't slip. It won't be some grand thickness of tape you'll need, maybe just one pass of tape or two. You'll see quickly the cap get more firmly in place. Ensure the square end of the cable is still getting centred in the square hole when you put it back on.

Great, thanks!

[Kenny_Z]

You could also put the speedometer cable on a drill to see if you can spin it up passed 35. I tested my gauge like that when I wasn't sure if it was the angle drive or the gauge that was going bad.

[dmruschell]

You could also put the speedometer cable on a drill to see if you can spin it up passed 35. I tested my gauge like that when I wasn't sure if it was the angle drive or the gauge that was going bad.

+1

If the gauge just seems to read a fraction of what it should, and you've just never driven it fast enough for the speedometer to read over 35MPH, the speedometer itself might need calibrating. The adjustment is easy to get to once you have the speedometer in your hands, but the only way to test it (without a machine that speedometer repair shops have) is to reinstall it, drive the car, and compare it to GPS. Then, if it's still off, remove, reinstall, and try again.

The odometer readings aren't changed by the calibration, so a good way to diagnose if it's the speedometer calibration or something with the cable/dust cap.angle drive is to drive a distance of one mile and see if the odometer changed one mile. If the odometer is accurate, you just need a speedometer calibration. If the odometer is not accurate, there's something else wrong.