# Ford 3930 Tachometer Not Working



## mooremarkt (Oct 30, 2013)

Recently, my tachometer and hour meter stopped working on my 3930 tractor. As it turns out, the flexible shaft that fits into the tachometer drive adapter assembly broke. I've purchased a new one but having a hard time getting the new one in place (can't get it to seat into the female end on the bottom of the adapter). I'm wondering what the correct way is to install this shaft? BTW, this adapter is attached to the engine below the oil filter and is driven by the oil pump.

I'm wondering if I should pull out the entire drive adapter assembly and if so how does it come out? I've tried some hand pressure to see if it will come out but it will not move and was hesitate to put a wrench on it. Any help would be greatly appreciated. I bought an IT service manual but it does not include any info on this particular item.


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## harry16 (Dec 8, 2011)

As you are aware, there is a small square female receptacle in the drive assembly that your cable fits into. First take a look with a mirror to see that the square receptacle is open. You may have a cable stub broken off in the receptacle, preventing the new cable end from entering it. Also confirm that it turns when the engine is running. 

If there is a cable stub stuck in the receptacle, I would try to get it with a magnet first or if there is enough sticking out that you can get a grip on it, maybe use a needle-nose pliar on it.

Another thing to consider - the tachometer may be frozen up, which could be the reason the cable broke off in the first place. Check that the tachometer turns freely. Had this happen to me on a Massey Ferguson. I put in a new cable not realizing that that the tachometer was frozen up and immediately broke the new cable. Oh well, you can learn from my mistakes!

If all is well, simply turn the cable with your fingers till it pops into the receptacle. Then screw in the cable housing connector. 

If you have to remove the cable drive assembly, loosen the bolt that clamps the assembly together, pry out the housing. Underneath, there will be a cable guide, an expansion ring and an o-ring to seal the joint. It's not rocket science, once you get into it. You can remove the oil filter for more room. Replace the o-ring to ensure no leakage when you are done.

Good Luck.


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## mooremarkt (Oct 30, 2013)

Thanks for the reply; I've removed the housing cover which came off easy enough. As you described, there is a cable housing; that's the part I'm not sure how to remove. From your reply, it sounds like I should just pry it out. It does not want to move by just prying with hand pressure. With this cable housing in place, it is difficult to get at the female receptacle to see if there is a broken piece still in it. I've tried a magnet but haven't got anything out. I'm planning to work on it some more today; hopefully I'll have some success.


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## harry16 (Dec 8, 2011)

I've attached a parts diagram of your instrument cluster and associated parts. It appears that the sleeve should pry out. I would expect relatively easy.

Compare your old cable end to your new cable end to see if any part of it is missing.

If you're not missing any part of the old cable end, I would simply put your new cable end into the receptacle and see if it seats in and turns. It might be that the new cable end is oversized/out of spec (made somewhere in Asia??). If you have a caliper, measure the two square ends. I've never really had a problem with inserting a new cable.

I see that Ford/New Holland have replaced the entire assembly (item #19) with a new part number. If you continue to have problems, you can buy the entire assembly (item #19) for $164 from Messick's Farm Equipment via the internet. Your local dealership should be able to get it for about the same price.


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## mooremarkt (Oct 30, 2013)

Finally got a chance to work on it again. Was able to get the broken end of the cable out but in the process I damaged item # 19. New one on the way. Getting closer to getting this fixed! Item # 19 (the base itself) was very difficult to remove.


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## mooremarkt (Oct 30, 2013)

New part came in yesterday. Tachometer working again!


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