GC2400 RPM guage pegged like at full throttle after starting

[reverton23]

Mine does this, and I just disconnected the cable and zip tied it out of the way, always planning to fix this. I took the tach apart last year, and tried to fix it, but there was a lot more wrong than just a spring, and the dealer didn't have a way to purchase just the parts it needed. They said I had to purchase the entire gauge assembly... so just figured instead of special ordering the $500 assembly, I'd just leave the cable off

 

[def38]

Have you tried lubricating the tach drive cable? I have several tach and speedometer drive cables (motorcycle) that I routinely lubricate with light oil (grease gets too viscous in the cold). I would remove the cable completely and flush the casing with WD40 or similar and then lube with ATF. If the instrument needs lubricating, spray the innards with aerosol silicone spray. It is non greasy (oily) and helps eliminate the squealing.

 

[cdaigle430]

Mine does this, and I just disconnected the cable and zip tied it out of the way, always planning to fix this. I took the tach apart last year, and tried to fix it, but there was a lot more wrong than just a spring, and the dealer didn't have a way to purchase just the parts it needed. They said I had to purchase the entire gauge assembly... so just figured instead of special ordering the $500 assembly, I'd just leave the cable off

Mine only did this when it was 20 degrees or colder. I bought and installed the new gear part $81, I was told it has diff lube for colder temps by the dealer. We shall see

 

[radios1]

Mine does this, and I just disconnected the cable and zip tied it out of the way, always planning to fix this. I took the tach apart last year, and tried to fix it, but there was a lot more wrong than just a spring, and the dealer didn't have a way to purchase just the parts it needed. They said I had to purchase the entire gauge assembly... so just figured instead of special ordering the $500 assembly, I'd just leave the cable off

Yipes!. I'd just replace the tach with an electronic one, aftermarket.. you'd have to get one that will work off a sensor mounted near the flywheel.. this is a cheap one. Amazon.com: DIGITEN 4 Digital LED Tachometer RPM Speed Meter+Hall Proximity Switch Sensor NPN Red: Home Improvement just epoxy the magnet to your flywheel, and mount the sensor in close proximity to the magnet..

 

[Industrial Toys]

I'm guessing that's like cheap, compared to what these digital LCD dash boards will cost.

I'm not sure I would want an aftermarket one with just a readout. That could be hard to read when changing.

 

[def38]

I'm guessing that's like cheap, compared to what these digital LCD dash boards will cost.

I'm not sure I would want an aftermarket one with just a readout. That could be hard to read when changing.

Digital tachometers are much cheaper to produce than a mechanical one driven by a cable off the camshaft with an attending angle drive, gearbox and drive cable. The only problem with these aftermarket digital units is the mounting of the Hall Effect Sensor and magnet. Access to the flywheel is usually difficult if not impossible leaving you with the HES mounted in the neighborhood of the front pully, a somewhat dangerous place for wires and such. Also, most of these digital instruments have no facility to accumulate engine run time.

I'm going to repair my OE mechanical tachometer with a new cable which I'll lubricate with lots of greasy ATF. I'll also remove the instrument from the panel and thoroughly clean and lubricate it. And while the mechanical tachometers are usually permanently crimped shut when manufactured, there is access to the inner workings through the illumination hole. I'll get some lube in there somehow.

Remember also, there are services that repair mechanical speedometers and tachometers. So, if you have an older machine that employs a mechanical tachometer, there are alternatives.

 

[Industrial Toys]

I have a Murphy Digital tach that I was going to put on my Diesel powered loader mounted snowblower, but I will use it on my chipper instead to make an auto feed since it has alarming outputs. There are a lot of analogue readout Tachs on E-Bay that can use the flywheel sensor.

 

[cdaigle430]

Mine only did this when it was 20 degrees or colder. I bought and installed the new gear part $81, I was told it has diff lube for colder temps by the dealer. We shall see

So far so good, last used it when it was 18 degrees. the updated gearbox looks like it did the trick, not toooooo expensive and easy very easy installation.

 

[Industrial Toys]

There are little blocks, aluminum extrusions with a rubber insert that allows you to clamp onto control cables and spray something down their length, while the cable is intact. They are inexpensive and mostly made (I think) for the snowmobile market.

I have never had any luck getting lubricant down the length of a cable, with the center still in there.

 

[def38]

On my M-F, the cable and sheath are secured to the instrument in the dash panel with a threaded collar which is easily removable. The driven or engine end is secured to the drive mechanism with a similar threaded collar, also easily removable. Once you have the cable disconnected from the engine side, the inner drive cable can be pulled out of the sheath, cleaned and lubricated. I sprayed some WD40 down the empty sheath and allowed the old grease and dirt to run out. Then I thoroughly flushed it with ATF followed by some motor oil and then inserted the new inner drive cable and connected it. The tachometer (referred to as the "tractormeter" in some manuals) now operates without bouncing or other anomalies.

Remember also, those of you who operate in cold climates, make sure your tachometer light bub is operating so as to keep the tach warm during cold temperatures. That may eliminate the squealing some of you experience.