Topic: trip meter won't go past 4.9 miles

[DarcyCB400F]

Trip meter goes 4.9 miles then hesitates briefly then it goes to 4.0 and starts climbing back to 4.9 only to repeat the process.
If I reset the trip meter to 000, it climbs to 4.9...you know the rest...

Is there anything I could try to fix this without tearing the guage apart??

[camelman]

I've been into about ten of these gauges. I've seen lot's of reasons for lockups like that. Best off pulling it apart. It really isn't that bad.

[DarcyCB400F]

Thanks Camelman!
I have been searching the forum and found some good links on how to take them apart...
I'm afraid to take the trip meter apart! 
Perhaps one day if I gather my courage.

[camelman]

If you pull the casing apart, then it is all exposed. The gears often fill up with oxidation. I don't know what is most recommended, but I've used bicycle chain lube with good success. It does a good job of removing the junk and lubricating the surfaces. Let it dry, then dab some silicon grease on and you should be ready.

By the way, the gear mechanism can strip if you let it go too long.

Camelman

[DarcyCB400F]

Thanks Camelman!
You've talked me into it! 
I never thought some cleaning and fresh lube would be the answer. I assumed (what a dummy ) that I would find broken bits laying inside... now I know that I will get the broken bits if left alone.

Great advice!
Thanks!

[DarcyCB400F]

UPDATE
Well I took it apart! I found out the inside of the .0 wheel is not round! It binds with the little pink gear as it passes by causing it to jump. The 0.m black wheel is also out but 00 and 000 work fine.
Now what? Would a little heat help? Heat gun, boiling water? I dont'

[Bodi]

I would go with hot water after making sure the numbers don't wash off in water. You have to be very careful cleaning those wheels so the numbers are not erased/dissolved.
Hot water gives you a known temperature, if that doesn't get them soft enough then try a heat gun but if the wheels are thermoplastic then the temperature range between "just soft enough to bend back" and "melts into a shapeless blob" may be very narrow. If it's not a thermoplastic then you'll just burn the numbers off and char the wheel. This is possible, inside those instruments gets damned hot in the sun and probably a thermoset or epoxy type plastic is used so the guts don't just melt into a puddle at the bottom on a hot day.
probably you'll have to look for a used speedo, I think any from the same company will have compatible wheels. (Nippon Seiki?)

[DarcyCB400F]

34 years old plastic did not respond to hot water at all, brittle as a potatoe chip! Plus the black numbers on white wanted to rub off just touching them without any water (white on black OK).
I am not able to fix it! 
So what I need now is a used trip meter... any offers??
I will post pictures soon!