855 Tach not working

[855Idiot]

My the Tach on my John Deere 855 Tractor is not working.

I checked the cable and it's not spinning--probably would explain the Tach issue?

What else do I look for?

I have not removed the cable to test it, yet.

I'm wondering if this is a common thing or is there usually more sinister problems?
Are there known issues with the tach, cable, engine cable hookup?

Is this usually an expensive fix?

Thanks,
Glenn

 

[jd110]

It sounds like your tach cable is broken. The question is why did it break? Sometimes the cables just break from wear and sometimes the tachometer seizes up and causes the cable to break. See if you can pull the inside cable out of the housing. Then stick it into the back of the tach and see if you can spin it by hand. If it spins freely and the needle moves, you should ok if you replace just the cable. If it turns out that the cable is not broken, then the drive on the front of the engine would be broke although I don't recall ever seeing one of these fail.

 

[RoyJackson]

They'll break from lack of lubrication too. That 855 has a lot of years on it and I doubt the cable (assuming it's mechanical) has ever been lubricated.

 

[855Idiot]

Pulled the cable last night.

It's square on one end and round on the other?

I'm assuming it's broken and that I'll have to dig into the front of the engine to retrieve the last little bit of the cable.
It was 1/2 inch short of the length of the housing.

I wanted to crank the engine over to see if anything in the engine cable area moved but it was dark and ....it would not crank (another thread).

Thanks for the ideas, I'll check the movement on the tach tonight.

Do they still make universal speedometer (tach) cables?
In yesteryear they made ones you could cut to length but I haven't seen them in ages.
Or is the cable a JD part only?

Thanks,
Glenn

...scraper blade, springtooth harrow and brushhog coming this weekend....

 

[dfkrug]

Glenn:

I have replaced these on my 955s, both the cable and the
tach/hr meters. The plastic worm gear does easily strip out in
the hour meter, I have found. Cables are pretty reliable, if
lubed. Both parts (from JD) are not that expensive. I think
the cable is about $25, if I recall.

 

[855Idiot]

Update!

I used an off-the-shelf, speedometer cable and put a tubular steel fitting on the end. I filed a groove across the fitting to match the engine side of the cable.

The tach is back to life! ...hours are now registering too!

Cost $4 and an hour of my time to make.

 

[dfkrug]

Update!

I used an off-the-shelf, speedometer cable and put a tubular steel fitting on the end. I filed a groove across the fitting to match the engine side of the cable.

The tach is back to life! ...hours are now registering too!

Cost $4 and an hour of my time to make.

....and think of how much more rewarding it was to DIY!

My 955s were great tractors. 2 highly annoying design issues are:
> the grille, which is hard to get on/off or to stay on, and you need
to remove it to get at air filter.

> and all those safety interlocks that eventually fail

 

[RoyJackson]

Update!

I used an off-the-shelf, speedometer cable and put a tubular steel fitting on the end. I filed a groove across the fitting to match the engine side of the cable.

The tach is back to life! ...hours are now registering too!

Cost $4 and an hour of my time to make.

GREAT!!!
Maybe you should change your screen name to 855Genius