Speedo

[FLATBEDFORD]

Today I took the old truck out for the first time in a few days. When I pulled out of the driveway, I heard a little "plink" like noise and the speedo shot up to about 50 mph. When I came to a stop, it just bounced from 0-100 mph. On the open road it was pegged. Was cool to see the needle all the way up there, but I would to know how fast I'm really going. The odometer seems to be working OK. I've never had one of these apart. I'm guessing that there is some kind of damper or spring that has either broken or come apart. Any suggestions? Is it electrical? I assume not.

[Ranchero50]

Probably a replacement deal. They're pretty touching to go tweaking on...

Jamie

[sideoilerfe]

Mine was just like that. I just took the cluster apart and replaced the speedometer with another one. You can take a drill to the replacement one to get the odometer to the same reading as your old one if you wish.

[basketcase0302]

Steve,

Look real hard at both ends of the cable before you go pulling the speedometer apart.
Look for a "stripped" end on the cable, where it goes into the speedometer.

I had one speedometer apart before, lots of little moving parts to lose very easily.

Basketcase

[6T7Merc]

Just wondering,correct me if im wrong but wouldnt it most likely be the gauge and not the cable since if one end of the cable was stripped it wouldnt be shooting past the current driving speed, or what he described happened when he was stopped?

[FLATBEDFORD]

If it was the cable wouldn't the odometer stop working too?

[Joshpow]

I do believe a cable would cause to odometer to not work right. I got an old speedo if you need to replace yours. It is out of a 70. The colored lense for the bright light indicator has fellen out, but you could replace it with yours. Let me know.

[sideoilerfe]

On mine, When you drove forward, it would peg to 100. it would stay there (even when stopped) until you backed up, then it would return to 0.

[FLATBEDFORD]

I have two guage panels from trucks that have gone to bump heaven. Both speedos seem to work. I want to keep the original mileage. I messed around with one of them, and it seems the electric drill would take about a week or so. I could only get it to go just beyond 100 mph. I need it to advance about 40,000 miles. At 100 mph that would take 400 hours or 16.66666 days! I don't have time for that. I removed the odometer to see if I could spin the numbers to what I want, and put it back in. I does go faster with the drill, but its pretty hard to hold everything down while turning it. The numbers are all geared together so I couldn't cheat. I even took the thing apart to see if I could reassemble it with the other mileage. That didn't work either, just some broken plastic. Then I started to actually think about what I was doing and realized that all I have to do is put the odometer with the original miles on the new speedo. Because the numbers will only re install with same mileage, unless I manually spin them, but we already covered that.
So, All I have to do is remove the dash panel from my truck and reinstall it with one of my spare speedos. While I'm doing this, I'll also switch to a nice steel bezel from the '68 I took apart this spring. Anything I need to know about removing the dash panel? Somebody else removed the two I have.

[Joshpow]

No real surprises on my 72. Just the 8 screws that hole the trim. Unplug the wiring, take the cluster apart and reverse all these steps. No real hard stuff.

[FLATBEDFORD]

I guess the only tricky part is reaching up in there to unplug, and to disconnect the speedo cable.

[bugser]

Nah..once you take the screws off, plenty, or maybe I should say, just enough room to reach in there and disconnect everything.

[6T7Merc]

I have two guage panels from trucks that have gone to bump heaven. Both speedos seem to work. I want to keep the original mileage. I messed around with one of them, and it seems the electric drill would take about a week or so. I could only get it to go just beyond 100 mph. I need it to advance about 40,000 miles. At 100 mph that would take 400 hours or 16.66666 days! I don't have time for that. I removed the odometer to see if I could spin the numbers to what I want, and put it back in. I does go faster with the drill, but its pretty hard to hold everything down while turning it. The numbers are all geared together so I couldn't cheat. I even took the thing apart to see if I could reassemble it with the other mileage. That didn't work either, just some broken plastic. Then I started to actually think about what I was doing and realized that all I have to do is put the odometer with the original miles on the new speedo. Because the numbers will only re install with same mileage, unless I manually spin them, but we already covered that.

so if im understanding right, your trying to reset your odometer to 0?
I did this when i put my rebuilt engine in and your right they are geared so you cant cheat. My way was just the kiond of easy way and i broke the end of the spindle that the gears are on and then slid them off, returned them to 0 and then glued the end back on with either crazy glue or cold weld.

[FLATBEDFORD]

Don't want to reset, just want to keep the original count going with the replacement speedo.

[FLATBEDFORD]

I replaced mine with a spare I had. I used the odometer from the broken speedo. It works fine. I also got to give everything a good cleaning. I used the metal bezel from the '68 I scrapped earlier this year. I think the metal looks so much nicer than the plastic. Best of all, it cost me nothing but a few hours of my time. Nice to get an easy one from time to time.