M35A3 Tach Sensor

[Gr8wheels]

Howdy, first post, great forum and thanks to all for the information, comments and entertainment contained herein.

My two week search for a replacement tachometer sensor for my newly purchased M35A3 is so far a failure. The one post on here a few years ago gave a CAT part # but the # is not working in the CAT parts search. All of the MV vendors,(several) I've inquired have no stock and no source So can I perhaps get a reccomendation here for a source? I would like to keep the truck stock so installing an aftermarket alternative tachometer and sensor would be the last resort.
Thanks

Additionally, I would like to know what life expectancy the stock tires should yield. I've measured about a 10% decrease in tread depth in 1,100 miles @ 55 lbs. of inflation mostly highway. The front tires are doing better than the rear but its a fantastic wear rate and a 50% greater expense than fuel,(6tires@600 ea.) if this is normal.

 

[AceHigh]

The sensor is not a Cat part. It is a standard off the shelf magnetic pickup and there are several sources for it. Are you sure it is bad? They rarely fail. Could have a piece of metal on the pickup, or could be slightly out of adjustment.

 

[Gr8wheels]

Yes, the sensor is kuput. I bech tested it. after removing it, cleaning it, re-installing per specs. Tachometer is getting power but neither RPM or hours are advanced when engine in running.
Can you recommend a vendor to purchase one? and a part #?
thanks

 

[doghead]

What part number do you have?

 

[doghead]

There are 2 manufacturer'snumbers listed for that NSN(2590-01-453-3777 ). 12448943 and EX2547

I found this thread listing an alternative part. http://www.steelsoldiers.com/electrical/36651-who-would-have-tach-sensor-m35a3.html

 

[Gr8wheels]

thanks Doghead,
That is the thread I spoke of, the CAT# is non-functional and the Manufacturers # American General is not available-----
Square #1
Is there an alternative source or valid CAT# for the M25A3 Tach sensor?

BTW those #s EX2547 are on the faulty sensor
The 5/8" x 18 tpi sensor is listed on a website for AETNA Eng. #8992 but without the technical specifications for the original I have no way of knowing if it will work- a $100.00 gamble with long odds

 

[AceHigh]

All the sensor does is send a pulse every time it is near the teeth on the flywheel. If the one you list fits, has 2 wires, it will work.

I put an aftermarket tach in mine, but first removed the sensor and made sure it worked. There is no magic here, just one pulse per tooth. If the new sensor does not work, you will need a new tach. They are almost unavailable out there, so hope the sensor does it for you.

 

[overtheedge]

Gr8wheels, did you ever find out if the 8992 from AETNA Eng. Works?

 

[lawnmowerman]

does any one know how to trouble shoot the electrical tach on the m35a3 mine is not working at one point the hour meter worked for a second then stopped wish it was cable driven

 

[Jeepsinker]

I have a good takeout....

 

[lawnmowerman]

what do you mean jeepsinker

 

[JohnnyBM931A2]

He means that he has a working one that he removed from an A3. He will sell it to you..

 

[lawnmowerman]

well I could be interested in tach but don't know if its the sensor or tach or what tach was installed new looks like an aftermarket if such a thing not sure how to check either how much are you asking for tach

 

[lawnmowerman]

well I don't know if its the tach or sensor sensor looks almost like it is plastic haven't taken sensor out yet but wouldn't know how to check it if I did but what are you asking for tach and if my sensor is plastic is that correct to m35a3 would change out both if I have too/ provided sensor was available

 

[Jeepsinker]

$65 plus the ride.

A steal considering it is the proper tach, and you can't find them anywhere. It shows 642 hours.

 

[lawnmowerman]

do you have a sensor for tach or do you think its neccacary

 

[Jeepsinker]

I don't have any idea if your sensor is good or not. All I have is the tachometer. Obviously both of them are prone to failure, so it is a 50/50 shot.

 

[lawnmowerman]

and it is for a m35a3 if yes ill take it how do we do it

 

[lawnmowerman]

so why did they go from cable to magnetic pickup guess progress but ill take the tach thanks for the good price I appreciate it

 

[Jeepsinker]

Pm sent