MF135 - Tractormeter/tachometer not counting hours

[RichMF135]

Hi,
I'm new hear and have a question. I have just purchased a 1972 Massey 135. So far most things work fine and she seems to run well. I have noticed that the 'Genuine 5904 hours' showing on the tachometer/tractormeter may have been that way for some time as I have used the tractor for about 4-5 hours and its not budged! It shows the engine revs fine but is not counting the hours.

Whats the best way to find the fault or is it just a case of replacing the whole unit? Any help would be appreciated.

 

[murphy1244]

Were you at PTO speed? If not it won't count.

 

[flusher]

There are two cables on the rear of the tach. The small one is for the light. The large one is connected to the transmission. Unscrew that cable from the transmission end and see if you can spin the wire inside that turns the mechanism in the tach. It may be jammed. YOu may be able to attach an electric drill to that wire, spin it and see if the tach pointer moves. If that wire turns but the pointer is stationary, then I'd look for a new tach unit.

Good luck.

 

[The kid]

Easy way to determine. Take a cordless drill and disconnect the opposite end from the tachmeter. You should be able to spin it up using the drill. If your tach is attached to your alternator the tachdrive may be bad. The drill method will prove if the tach is working. On each end of the tach cable is square cut. Cables have been known to seize due to moisture getting in causing one end to strip. Make sure both ends have nice sharp square corners. Graphite is the best to use lubricating the cable. If the needle moves as it should but the clock is not working could be a bad sign that internal gears are either seized or stripped. The tach/proofmeter should be working when ever the engine is running. BTW, welcome to TractorByNet and greetings from Tennessee. -kid

 

[RichMF135]

Thanks to all for the replies.

The Needle works fine and shows the Revs without issue, it's the clock showing the number of hours worked that's not working.

If the rev/rpm needle is working and the hours aren't ticking around with the engine running at PTO RPM, do I take it that I need to replace the whole unit?

Thanks again.

 

[The kid]

Thanks to all for the replies. The Needle works fine and shows the Revs without issue, it's the clock showing the number of hours worked that's not working. If the rev/rpm needle is working and the hours aren't ticking around with the engine running at PTO RPM, do I take it that I need to replace the whole unit? Thanks again.

If the proofmeter is not working more than likely the small centrical clutch inside is corroded. I have taken a similar one apart and cleaned it and got it working again. You also take the change of damaging it beyond repair. They do sell reproductions of that tach/proofmeter. They aren't hard to remove from the tractor. Be sure you get the correct one CC vs CCW rotation.

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