Speedometer/Tachometer Not Working

[Workstead]

I have a 1998 MF 1250 tractor that has a non-functioning speed indicator. It has a combination speedometer/tachometer. The dial reads both functions on the same long needle that pivots at the center. One reads from top to bottom and the other reads from bottom to top.

I have the engine top cover and side panels off to paint them and while the're off I thought I would try to fix whatever is wrong with the speedometer.

If I knew how it worked and what it is connected to it would help. I am assuming that it is a mechanical device that has a cable that goes to the engine/transmission. It got too dark tonight to look at it but I hope to get to it tomorrow afternoon.

Maybe many tractors use the same type of speedometer as the Massey Ferguson or maybe the MF has a unique system.

The hour meter is also not working.

Can you give me some helpful advice?

Thanks,

Clem

 

[Richard]

I'd look to see if it has a mechanical cable. If so, is it firmly attached at both ends. if so, I'd remove the engine end (leave attached to tach). If you can twirl it (attach a variable speed drill?) and see if tach works.

If not, undo other end, see if cable turns (could cable be split inside the sheath?)

if all that is ok... then I guess it gets interesting. I'd put it back into engine and see if tach end turns (if not, peerhaps something wrong with drive gear to it?)

If it works, then you might have something buggered inside the tach itself.

If this thing is electronic and not mechanical then of course, ignore everything I said above and send me $50 for blowing nothing but hot air

 

[Workstead]

I'd look to see if it has a mechanical cable. If so, is it firmly attached at both ends. if so, I'd remove the engine end (leave attached to tach). If you can twirl it (attach a variable speed drill?) and see if tach works.

If not, undo other end, see if cable turns (could cable be split inside the sheath?)

if all that is ok... then I guess it gets interesting. I'd put it back into engine and see if tach end turns (if not, peerhaps something wrong with drive gear to it?)

If it works, then you might have something buggered inside the tach itself.

If this thing is electronic and not mechanical then of course, ignore everything I said above and send me $50 for blowing nothing but hot air

Sorry, no $50. The meter is analog.

I'll do as you suggested and see what happens. I hope it is as simple as a disconnected cable or maybe broken cable.

I'll let you know.

Clem

 

[Workstead]

I checked it out late this afternoon. After I opened the dash I saw that the speedometer cable was disconnected. I connected it back up and while I was checking to see how the hour meter was hooked up (I didn't see any wires coming out from the area behind the hour meter) it started to rain. I quickly screwed in the four screws that hold the dash and will check it out when it is dry out. The trator is an outside tractor until I can get an equipment shed built.

Clem

 

[Workstead]

It's fixed!

I reconnected the speedometer cable and now the tachometer and hour meter are working. I wish all problems were as easy to fix as this one was.

Clem

 

[rustyanchor]

Glad you got your tractor fixed.
My limited knowledge of the speed/tach/hour meter is: The hour meter will count hour for hour, if you are running at PTO speed, in my case 540 PTO is 2500 or so engine rpms. If you are running less than PTO speed the hour meter doesn't count correctly. My hour meter shows 96 hours but since I run around at 12-1500 rpms most of the time, I figure I have almost double that time on the engine. I just have to take the reduced hours into account for the maintenance intervals.

Mark

 

[Workstead]

Glad you got your tractor fixed.
My limited knowledge of the speed/tach/hour meter is: The hour meter will count hour for hour, if you are running at PTO speed, in my case 540 PTO is 2400 or so engine rpms. If you are running less than PTO speed the hour meter doesn't count correctly. My hour meter shows 96 hours but since I run around at 12-1500 rpms most of the time, I figure I have almost double that time on the engine. I just have to take the reduced hours into account for the maintenance intervals.

Mark

Hi Mark,

What brand of tractor do you have? After I connected the cable and started the tractor I had it idling for about 10 or 15 minutes. I didn't time it. The hour meter did advance 2/10ths. As I sat there I was trying to figure out how the hour meter would read accurately if the engine runs at different speeds. MY operators manual did state that the speedometer reads accurately only when the range and gear are in the highest position. I guess that's why there is a decal on the fender that gives the speed for each range/gear position. I can't read my decal because it is faded but there is one in the manual.

Thanks for the info about the accuracy of the hour meter. I will have to check mine.

Clem

 

[rustyanchor]

Clem,

I have a Farmtrac DTC 360. It has been a great tractor, the speedometer/tach/hourmeter are all mechanical and I suppose it works much like an electric meter, the faster the engine spins the faster the meter rolls. I think the meter is calibrated to 2500 rpm. I suppose if I was real curious I could run at 2500 for 15 min and see if the meter shows a quarter hour.

Be good, be careful, and have fun with your tractor

Mark

 

[Workstead]

Clem,

I have a Farmtrac DTC 360. It has been a great tractor, the speedometer/tach/hourmeter are all mechanical and I suppose it works much like an electric meter, the faster the engine spins the faster the meter rolls. I think the meter is calibrated to 2500 rpm. I suppose if I was real curious I could run at 2500 for 15 min and see if the meter shows a quarter hour.

Be good, be careful, and have fun with your tractor

Mark

Hi Mark,

I did a test today to see what the deal is with hour meters. It seems that an hour is not an hour unless the engine is running so the PTO speed is 540 RPM.

On my tractor that is between 2500 and 3000 RPM. I was moving things around a little today, so I ran the engine at 1500 RPM and timed 1/10th of an hour. At that speed it took 9 minutes and 40 seconds to register 1/10th of an hour. It should have taken 6 minutes.

When I was in the military about 45 years ago I was dumbfounded to learn that if we ran the 2-1/2 ton truck in reverse that the odometer ran backwards also. We actually took miles off of the odometer by driving in reverse.

I wonder if I drove the tractor in reverse if the hour meter would go backwards? It doesn't, I already checked.

I like the way you closed your post. My mother used to tell me before I went our on a date to " be good, be careful and be home early." Thanks for the reminder.

Clem

P.S. We used to be "almost neighbors." I lived in Glen Allen, a suburb of Richmond, from 1988 to 1992.

 

[rustyanchor]

I usually don't need to run at PTO speed, or better said-Slower is better for me, less damage to things.
I wonder if you run your engine backwards if it will take hours off?!!!

Suffolk is a temporary home until I retire from the Navy, bought a piece of land in TN to permanently retire on.

Mark