Speedometer Help

[0ver0range]

Hi everyone,

 

The speedometer on my 'brand new' '79 620 remains stuck on 40 mph until I reach that speed, then it functions as normal at 40 and above. Would this be indicative of cable issues or do you think I should buy a new speedometer head?

I greatly appreciate your input.

[datzenmike]

Sounds like the gauge. Easy enough to remove, so replace, or see if the needle is sticking against the face or elsewhere.

[Draker]

Agreed, sounds like the gauge. Easy enough to come by in the classifieds. Be glad it's not your stock tach stuck at 2k rpm

[distributorguy]

I'd be willing to bet the gauge is not broken, just something preventing the needle from dropping down to zero.  A good cleaning is in order.  My bet is that a chunk of "something" fell into the spring and is preventing normal motion.  

[Draker]

I'd bust it open.. if not obvious.. then replace.

[Seeker > 620 KC]

Hey Over,

 

It if is an original Tach they are hard to come by and expensive to replace if it is dead.  Early tachs are not serviceable if there is anything seriously wrong with them, as the parts are all mounted on the main unit.  I wouldn't take it apart and risk screwing it up if it is partially working. Most guys ruin the needles and shaft trying to get the face off.

 

Later tachs have a circuit board that can be replaced if they are dead, and if the shop can source another one to canibalize.

 

There is a shop near me that specializes in Foreign tachs, and they will bench test it for free, and give you a repair estimate for free, but they are slower than snot, like getting a boat serviced. But you'd have to uninstall it, and pay shipping to get it to them. PM me if you're interested for their info.

Seeker 

[abbylind]

I thought he said speedometer........not tach.....

[Seeker > 620 KC]

Oh crap, did I read that in a flash. My bad.

[Seeker > 620 KC]

Speedos are very plentiful. Let me know if you need one, I'll sell you one cheap.

[sebpv]

Love mey some speedos

[DanielC]

I am not so sure that speedo is stuck on 40.

[0ver0range]

Thanks for the suggestions! I'll plan on taking it out this weekend to see if I can fix the issue.

[0ver0range]

Well, I was working on taking the speedometer out from behind the dash when I heard a snapping sound and the needle slowly dropped down to 10 mph....

so it magically works now, which is a good thing, and I'll leave it as is until I decide to take it out another time. Thanks for the help.

[Draker]

It's magic!!

[sebpv]

its SORCERY!!

[datzenmike]

I'd rather be lucky than good.