The tachometer never worked on this truck. It held steady at 2800 rpm, so I wondered if the needle had just stuck up there on one bad shift by the PO. No such luck. The needle spins freely all the way around. We pulled it out to have a look. The drive cable off the IP is fine, but the internals of the tach look worn out. It looks like a magnetic disk/drum drive, but that seems to have play. There's a little copper thing that may have once been a spring, now collapsed around the shaft that holds the needle. Perhaps if the spring were intact, the tach would still work. Or perhaps the magnetic drive seized up and spun the needle around, killing that spring. Pics below. My son ran a web search but didn't find any for sale. Anybody know of a rebuilder out there?
Look familiar? https://www.ebay.com/itm/124972458099?hash=item1d18f06073:g:l2kAAOSwpJJhdzop
SCORE !! Let's go Brandon. Or ... I could buy this one for $300 https://www.ebay.com/itm/202260700738?epid=2075401871&hash=item2f17ad5e42:g:si0AAOSwCXhama4e Thank you Sir
Welp ... I still need to find a new tach or somebody who can fix mine. My NOS fleabay hopes were dashed when that NOS tach arrived. The guy sent me an electronic tach. Cummins Big Cam 3 has a cable drive off the IP. He hasn't even answered my messages asking for a return, and if he has the correct one to sell. I'll ask fleabay for help after the waiting period is up, tomorrow. Here are comparo pics of what I received, which he listed for "70s/80s International trucks." Is there any 70s/80s International truck with an electronic tach? I bet they started in the 90s, but I'm not sure. He only posted one front pic in his fleabay listing. The front looks almost the same. I should have asked for more pics...
Damn. I'm sorry to read that citing I forwarded the link for you.
Hey that's life. I should have insisted on full photos. Meanwhile, I found the part number and IH dealers can still get it ... for $250 ! So now I'm looking around the web for manual tach part no 478674C1 I found a couple on fleabay but the cable attachment uses a little screw, while mine uses a spring clip. Mine:
You may have already seen this but new, and used on ebay: https://www.ebay.com/itm/324973356563?hash=item4ba9ebe613:g:VrIAAOSwMl9h0hq9 https://www.ebay.com/itm/324963283334?hash=item4ba9523186:g:G6YAAOSwEBFhybtH https://www.ebay.com/itm/324404629468?epid=2078917994&hash=item4b8805cfdc:g:4E0AAOSwbyxfylrt
I'd spotted the tach alone, that's the pic I posted above. But the whole cluster...wow! That would be nice. I'm gonna look into it. Right now I only have oil pressure, coolant temp, and air brake pressure that work right. Speedo is wonky, only good for a general idea. Others are dead.
Ahhh, the joys of dump truck work. Hope something works out for you.