Ford 540 Industrial 1969 Tachomoder not showing RPM's

Utz · Jun 20, 2012

I recently got a 1969 Ford 540 Industrial tractor (3 cylinder diesel); it is very similar to a Ford 4000 series but came with a loader from the factory. The Tachometer does not show the RPM's nor does the hours meter work. I disconnected the cable at both ends and it spins freely so I does not seam to be broken or damaged. I suspect that I either need a new proofmeter assembly or that something is wrong on the other end of the proofmeter cable (not sure what that is called where it connects to the engine). Is there a way to check to see what parts I need rather than just guessing. Is it possible to fix the proofmeter or best to just get a new one for $130-- The fule gage, and tempeture still work). Thanks for any help you can offer me

RickB · Jun 21, 2012

Connect the cable to the proofmeter and spin the other end by hand. You should see the needle jump a little if the cable and tach are OK. If so, there is a short cable driven from the oil pump that drives the long external cable that likely has failed. Alternatively, check to see that the short cable female end turns when the engine is cranked over, or that it cannot be easily turned with a small screwdrivr inserted into the female end (tractor not running or cranking, of course). If the short cable extending down into the engine is broken post back for more info.

Utz · Jun 21, 2012

RickB said:
Connect the cable to the proofmeter and spin the other end by hand. You should see the needle jump a little if the cable and tach are OK. If so, there is a short cable driven from the oil pump that drives the long external cable that likely has failed. Alternatively, check to see that the short cable female end turns when the engine is cranked over, or that it cannot be easily turned with a small screwdrivr inserted into the female end (tractor not running or cranking, of course). If the short cable extending down into the engine is broken post back for more info.

Thanks RickB. I will do the tests you suggest tomorrow and let you know what I find.

Utz · Jun 21, 2012

RickB; I could get the RPM needle to move by spinning the male end of the cable near the oil filter. I also could easily turn the female end (at the engine) with a small screwdriver as you suggested. When I cranked the engine (without my screwdriver in it of course) I did not see the female end move. So it looks like all signs are pointing to a failed short cable driven from the oil pump. I have picked up both an operators manual and a parts book for the tractor but have never messed with an oil pump or one of these short cables. Thanks again for your help.

RickB · Jul 12, 2012

Check the parts catalog for the breakdown of the tach drive on page 12A01 Instrument cluster. Buy reference #'s 25 and 24, the o-ring and short cable. Remove the engine oil filter for room and to see what you are doing. Remove the bolt reference # 28 and the cover which is not called out. Fish the broken cable out, replace the o-ring and thread the new cable and cover down, bolt securely.