2H/12HT Tachometer (rpm) sensor/sender & gauge info thread

[WaifuBeater]

So, I'm not sure anyone have done it before, and since I couldn't find any info neither here nor on the web – here we go.

For two simple reasons of:
– the sensor, being just a coil in epoxy, is notoriously expensive (250-350$ last I checked in 2025)
– I don't like aftermarket gauges that don't fit the era,

I want to share all the technical information on those pieces of equipment, for anyone who would dare trying to hook up some other sensor that costs an order of magnitude $$ less or two.

I'll start with the measurements of the stock sensor itself with pics and description in case the first ones won't last. Will I be able to "finish" this info thread – dunno, time will tell!

 

[WaifuBeater]

part number: Toyota 83180-60040 or 8318060040 (for the search engine)

The most important bit – stock thread size is metric, M20x1.5. The threaded section is 8mm in length. Length from the hex head base to the end of the thread is 11mm (so there's a 3mm relief in between).

Total length from the hex head base to the end of the pickup pole is 38mm. That would be also approximately the same distance between the surface of the bellhousing (where the sensor is screwed into) to the engine's flywheel, plus a couple mm of clearance.

The pickup cylinder is 14mm in diameter.

The hex head is for a 24mm wrench.

 

[WaifuBeater]

Pickup cylinder diameter – 14mm

Hex head height/thickness – about 9mm (mind the epoxy layer as well)

 

[WaifuBeater]

A quick search for sensors from other engines gave me this finding:

(out of all!) John Deere tractors, engine speed sensor, part number RE519144. One info link.

Same M20x1.5 thread size, same 24mm hex-head, same thread+shaft 38mm length.

The only thing that bothers me is that the connector on the back surface of the sensor might interfere with the neighboring vehicle parts. It's tight there on my FJ62, but I'm not sure about other models. But you could probably cut the end and solder the wires, then cover it with epoxy or something.

Found a photo on the web as well, the scale is imperial, so 1.5" of thread+shaft length roughly equates to 38mm. Also attaching a photo of the connector on the back. If anyone knows the connector part number for the mating female plug – posted info appreciated. It looks very familiar but I couldn't find it yet.

Looks promising, hopefully the internals are very similar. Will order and try it out, but the lead times here are 2 weeks to 1 month from AliExpress.

 

[ToyotaMatt]

A quick search for sensors from other engines gave me this finding:

(out of all!) John Deere tractors, engine speed sensor, part number RE519144. One info link.

Same M20x1.5 thread size, same 24mm hex-head, same thread+shaft 38mm length.

The only thing that bothers me is that the connector on the back surface of the sensor might interfere with the neighboring vehicle parts. It's tight there on my FJ62, but I'm not sure about other models. But you could probably cut the end and solder the wires, then cover it with epoxy or something.

Found a photo on the web as well, the scale is imperial, so 1.5" of thread+shaft length roughly equates to 38mm. Also attaching a photo of the connector on the back. If anyone knows the connector part number for the mating female plug – posted info appreciated. It looks very familiar but I couldn't find it yet.

Looks promising, hopefully the internals are very similar. Will order and try it out, but the lead times here are 2 weeks to 1 month from AliExpress.

View attachment 3850702

View attachment 3850727

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Excellent TECH write up !

- this is not any toyota or japan oem parts maker connector profile male housing ...

i did hit your link above ...

Manufacturer :​

: Agro Parts
Country of origin: Italy
- this = Euro Spec. connector oem makers , like Bosch or FAYE
below is what i think is the Official BOSCH.com website , for service parts electrical wire harness realated ,
i linked the Automotive Connectors page 1
but this link is part of a much bigger and broad base all kinds of electrical BOSCH parts ...fyi
i would start with calling and leaning Hard on John Dear where you purchase this sensor , they are the logical 1st path choice of least resistance here


- if you tell them a hint that you are buying this tach sensor for a retrofit mod on a non-John Deere " THING " ? the John Deere parts person will ghost you on the extra time on the harness side connector plug needed research time . Your gonna be asked what model Deere product you have most likely ...fyi
because it most likely is on the EPC diagram images with the wire harnesses


how come your not simply going with one of the OEM TOYOTA options here ? not sure if i fully understood that above ?



matt

.

PS Connectors | Homepage

bosch-connectors.com

 

[KeepCruzin]

If you are looking for a secondary alternative:

This sensor from Dakota Digital: Universal Flywheel Tachometer Pickup Sensor - https://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=1142/mode=prod/prd1142.htm
Paired with this thread pitch adapter: Fitting Reducer Metric M20 M20X1.5 Male to M12 M12X1.5 Female Bushing Plated Brass - https://www.fittings.space/gbm21-m20x15m-m12x15f
Paired with this tachometer sensor to gauge adapter: SGI-100BT: Universal Speedometer and Tachometer Interface - https://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=1192/category_id=-1/mode=prod/prd1192.htm

I understand that this combination is NOT cheaper than the factory sensor replacement, however, it does allow for changing from a 24volt gauge to a 12volt gauge, which in my opinion is almost impossible to replicate. It also lets you adjust the tooth count/RPM to your specific gauge. Im unsure how the above mentioned John Deere sensor will read, and whether the calibration will be tunable/remotely close to the original sensor unit.

For example: This combination would allow you to use an FJ60 12v gauge (period correct) with a 12HT or 2H that has been converted to 12volt.

I have not extensively tested this combination, but it is the route I plan to go with my 12HT swapped FJ40. I will pair this combination with either the following:
Tachometer Bezel – Full Kit - https://teqtach.com/product/tachometer-bezel-full-kit/ and a factory 12v FJ60 gauge behind the housing, OR I will pair it with a complete gauge cluster from Dakota Digital such as: 1962- 84 Toyota FJ RTX Instruments - https://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=1184/category_id=682/mode=prod/prd1184.htm

I have struggled with finding a good solution to 12HT / 2H tachometer systems for two diesel swaps now.
My proven method has been a 24v step-up adapter to run the gauge in its original configuration, but it doesn't play well with modern/integrated gauges like the Dakota.

I look forward to hearing how your alternative solution goes! Its great to see other people pursuing some innovative options.

 

[cuteo100]

@KeepCruzin Did I read that Dakota sensor thread correctly at M12x1 instead of M12x1.5? If so that adapter referenced above is for M20x1.5 to M12x1.5.

 

[WaifuBeater]

connector

Found it – it's Delphi/Aptiv GT 150 2 pin, 3.5mm pitch waterproof. There are a couple different styles, but both should fit. I got the one with the big shroud around

although the assembly is already very bulky and won't fit in my case, unless I drill somewhere else and not in the stock surface of the bellhousing

Good thing is -- thread diameter and pitch are M20x1.5, as stated on the agrodoctor.eu -- just measured these myself.

But with this John Deere sensor the main culprit is not the housing -- you can just cut it and solder the wires directly.
The impedance is different -- simply measuring the resistance gives me around 3.5-4k Ohms, while our little stock brass friend over there is just around 350 Ohms, so about 10 times the difference. Can't say about the dynamic behavior.

I'm gonna have to make up a test rig for this one with a scope/soldering iron/24V power supply/some kind of ferric flywheel to see if it's gonna work and figure out what can be done to make it work.

Question: Before I dive into reverse-engineering the tach itself -- I can't find the tach sensor on the schematic in the HJ60 wiring diagrams. One of the pins obviously going to the tach input, but is the second one connected to ground or to a reference voltage?

if you tell them a hint that you are buying this tach sensor for a retrofit mod on a non-John Deere " THING " ?

That's why I don't usually talk to official distributors, but rather to the Chinese sellers who clone the sh*t out of everything They're usually much more pleasant when it comes to weird requests like part measurements etc. And you can't compete with the price, especially when these parts are pretty much sacrificial material for research purposes. I bought this sensor for 10.90$ and 1.93$ for the connector, shipping included.

how come your not simply going with one of the OEM TOYOTA options here ? not sure if i fully understood that above ?

It's SPITE! I'm not willing to pay 200$+ (new) for a tiny brass cylinder with a copper coil and a magnet inside it, whatever it's rarity and perceived value is. The top price the thing should cost is 50 bucks US in my opinion if produced on a small scale, where the most expensive part would be the piece hex brass stock to machine away.

 

[WaifuBeater]

I look forward to hearing how your alternative solution goes!

Thanks, I'll try keeping things posted.

I understand that this combination is NOT cheaper than the factory sensor replacement

You'd think, but it actually would be At least if you go with a chinesium universal sensor for 10$. But I'd rather avoid juggling two different voltages (24 and 12 in this case) if possible – gotta scope the tach I have for that.

 

[ToyotaMatt]

@WaifuBeater ,

thanks for the super high level tech reply above ...
please tell me what exact model year HJ60 ....... tach sensor on the schematic in the HJ60 wiring diagram you require ?

i have each single model year , year by year ( 1976-1992 ) commercial vehicles electrical wiring diagram stand alone fsm's ......... the original paper print media fold-out's / accordion pages ...

i will post the correct detailed system circuit break-down for you here .....

matt

.

 

[WaifuBeater]

please tell me what exact model year HJ60

1989 HJ60LG-MNZW