Trip Odometer

[MadDrOlds]

1985 442 with 37,000 miles. (For this thread, just trust me on this.) Odometer works fine and cable is secure and no leaks at the transmission. Speedo works fine, maybe runs a few MPH slow (5 or less). Trip odometer is at 000.0 and doesn't move at all. Reset button does nothing. Short of an internal gear being busted, I'm struggling to understand how these three things can happen at the same time. Any tips?

 

[69hurstolds]

Yup. Somtin's not engaging. Without knowing what's going on with it, it's hard to say. Does the reset knob turn? It's not a button per se. If you look at page 44 in your 85 Oldsmobile Owner's Manual about midway down the first column, it tells you to push it in, and twist until all the numbers line up to zero.

WHY on earth did they think a little knurled toothpick would suffice to be a reset stem is beyond me.

 

[MadDrOlds]

Yup. Somtin's not engaging. Without knowing what's going on with it, it's hard to say. Does the reset knob turn? It's not a button per se. If you look at page 44 in your 85 Oldsmobile Owner's Manual about midway down the first column, it tells you to push it in, and twist until all the numbers line up to zero.

WHY on earth did they think a little knurled toothpick would suffice to be a reset stem is beyond me.

You’re refreshing me-this is just how my my 84 Monte was in 1991.

To answer your question, the “toothpick” turns but neither pushing nor turning nor pushing and turning does anything. The 0000 doesn’t move a nanometer.

 

[ck80]

With nothing other than picturing how the mechanism works and is set up, it SOUNDS like the internal mechanism that actuated to reset the trip odometer has, for lack of better term, a 'closed' position where the trip odometer logs mileage, and, an 'open' position that occurs when the shaft/button are pushed in and turned.

If the mechanism became stuck into 'open' the trip odometer would set to zero, but, remain in an interrupted mode where new mileage couldn't be logged.

I've never taken one all the way apart, but, if the knob worked by a prong on the 'toothpick' as you've dubbed it rotating and them either pushing open, or on, some tab or other part to trigger the reset, and, either than prong, bump, whatever you want to call it, came off to hold things in the 'open' position, or, it was turned a bit too aggressively by someone and bent/forced whatever it triggers internally to become 'open' for reset purposes and can't spring back to 'closed', it would lead to the symptoms described.

Just brainstorming here