troutsqueezer
Veteran Member
For anyone who is about to troubleshoot or replace your mechanical tachometer/hour meter cable, here is what I just went through. Searching TBN, I did not find much in the way of what to expect so thought I'd throw in my two cents for anyone doing a search on the subject.
My tach cable broke on my B21 last week so I ordered a new one through the local dealer. It was easy to install, just loosen the alternator, swing it down and unscrew the cable from the engine block. The other end involved removing the instrument panel and unscrewing that end as well. I put the new one on, buttoned everything up and started up the tractor. Still didn't work. Took it all apart again and sure enough, the new one had twisted in two. I thought maybe I didn't seat the U-shaped metal piece onto the pin in the engine well enough and somehow it malfunctioned so I brazed the cable back together and re-installed the cable - looking back, this was bad thinking on my part but hindsight is 20/20. This time I did not connect it to the tach and started the engine to make sure it was turning, which it was. I hooked it up to the tach and the darn thing still wouldn't work. Took it apart and the cable twisted in two again. It didn't break where my brazing was so at least I knew the joint was strong enough.
I removed the tachometer and dang if it wasn't frozen solid. After pricing out a replacement (too much $$) I stuck a screwdriver into the tach and forced it to turn whereupon it started to spin freely. I sprayed some WD40 into the sleeve which seemed to be where the binding was happening and it looks like that fixed it (for now). I took the broken cable and brazed it back together again. Fortunately, the wound steel the cable is made of allows brazing to take place. The tach readout is rock steady now which it wasn't before. We'll see how long it lasts.
So my advice, make sure your tach turns freely before installing a new cable, that could be why it broke in the first place. Just stick the square end of the cable into the tach and spin it with your fingers before installing.
My tach cable broke on my B21 last week so I ordered a new one through the local dealer. It was easy to install, just loosen the alternator, swing it down and unscrew the cable from the engine block. The other end involved removing the instrument panel and unscrewing that end as well. I put the new one on, buttoned everything up and started up the tractor. Still didn't work. Took it all apart again and sure enough, the new one had twisted in two. I thought maybe I didn't seat the U-shaped metal piece onto the pin in the engine well enough and somehow it malfunctioned so I brazed the cable back together and re-installed the cable - looking back, this was bad thinking on my part but hindsight is 20/20. This time I did not connect it to the tach and started the engine to make sure it was turning, which it was. I hooked it up to the tach and the darn thing still wouldn't work. Took it apart and the cable twisted in two again. It didn't break where my brazing was so at least I knew the joint was strong enough.
I removed the tachometer and dang if it wasn't frozen solid. After pricing out a replacement (too much $$) I stuck a screwdriver into the tach and forced it to turn whereupon it started to spin freely. I sprayed some WD40 into the sleeve which seemed to be where the binding was happening and it looks like that fixed it (for now). I took the broken cable and brazed it back together again. Fortunately, the wound steel the cable is made of allows brazing to take place. The tach readout is rock steady now which it wasn't before. We'll see how long it lasts.
So my advice, make sure your tach turns freely before installing a new cable, that could be why it broke in the first place. Just stick the square end of the cable into the tach and spin it with your fingers before installing.
