Intermittent tripometer, yet drive gears look fine

[Twisted2]

About a month ago, I reset the tripometer after getting gas, and noticed that it remained at zero while driving. I tried pressing the reset button a few more times, but the meter wouldn't start turning again. After several miles, it suddenly started working again. I figured the drive gears needed replacing, and ordered a new set. In the time waiting for the gears to come, the tripometer has simply worked sometimes, and other times, not...seemingly at random. I'd assumed the odometer had also been stopping and starting, but honestly am not so sure. When the gears came, I took the gauge cluster apart, expecting to be able to see the problem. Alas, the gears in question (of which I received replacements) show zero signs of wear; they look just as good as the new ones. All other gears in the linkage look fine, and when I turn the main drive wheel with my finger, everything turns over as it should. The speedo and tach work perfectly. Has anyone seen anything like this before?

My suspicions:
--The motor that drives the odo/trip meters is working intermittently--possibly due to a short in the electronics of the cluster.
--Due to play in the linkage, one or more of the six gears I can see pulls away from its mating gear sometimes.
--The teeth on the tenth-mile indicator (the white wheel) are worn enough to not make contact sometimes. I doubt this.
--The reset botton "clutch" mechanism is acting up somehow.

Any thoughts? Thanks again.

 

[Murder Snake]

just 'cause the gears look all right, they may not be. have seen it on a car I just helped fix. either that, or your motor is going bad for the trip odometer.

 

[Twisted2]

just 'cause the gears look all right, they may not be. have seen it on a car I just helped fix. either that, or your motor is going bad for the trip odometer.

Thanks for the reply, SnakeBit. I was wondering if that was possible. I swapped them out anyway, and the meters worked fine in the five miles I drove the car afterwards. Guess I'll know for sure in a day or two. I'll try the motor if it's still acting up. Good insight.

 

[Murder Snake]

Thanks for the reply, SnakeBit. I was wondering if that was possible. I swapped them out anyway, and the meters worked fine in the five miles I drove the car afterwards. Guess I'll know for sure in a day or two. I'll try the motor if it's still acting up. Good insight.

ho problem, glad that it worked for you. I noticed on the car I just did that the gears actually seem to get kind of like soft or something. then I don't think they mesh well and probably stick.

mwolson on here is the one that got me straight on these things so glad I was able to pass on the information to help someone else like he did for me.

 

[Twisted2]

Agreed...mwolson is a knowledgeable cat. Everything still seems to be working as it should...seems that you two were correct. Thanks again!

 

[Twisted2]

One thing I should probably add, in case someone else ever has this problem, and it makes no damn sense to them either: The problem still seems to be fixed, yet I really don't understand why. Another thing I did when I was rummaging the insides of the cluster was to clean a layer of grime from between the motor casing and the base of the worm gear. There was maybe a mm gap between the two, and a thin, tar-like layer of pure filth had formed in there. It's possible, I guess, that that gunk was impeding the free rotation of the worm gear under certain ambient conditions. It didn't seem like there was that much...but then, I doubt it would take much to drag that puny motor to a stop. Just wanted to share.

 

[Murder Snake]

good info to have. thanx for posting.

 

[Tantrix]

One thing I should probably add, in case someone else ever has this problem, and it makes no damn sense to them either: The problem still seems to be fixed, yet I really don't understand why. Another thing I did when I was rummaging the insides of the cluster was to clean a layer of grime from between the motor casing and the base of the worm gear. There was maybe a mm gap between the two, and a thin, tar-like layer of pure filth had formed in there. It's possible, I guess, that that gunk was impeding the free rotation of the worm gear under certain ambient conditions. It didn't seem like there was that much...but then, I doubt it would take much to drag that puny motor to a stop. Just wanted to share.

Yeah, you're probably lucky the motor didn't burn up. If it's still working fine, I suspect the worm gear was slipping on the primary gear somehow since new gears wouldn't fix it if it was the motor. My main gear looked like it exploded...both the left and right shaft were sheared clean off. I ordered some new gears with lifetime warranty, did it in about 20 minutes.