M1009 Tachometer from HMMV

[donalloy1]

Fellow SS'ers, has anyone tried using a Tachometer from HMMV on CUCV vehicles? Found one on ebay ( NOS 6680-01-474-0384 ) that looks like what I have been looking for.

Not sure of diamensions and how it get its input??? Any thoughts....

 

[Recovry4x4]

I can't definitively answer your questions but here is what I've found doing other research. The HMMWV engines have a mechanical tach drive that goes in place of the vacuum pump on your Oh-9. You need vacuum to shift your 400 Turbo. Besides that, there is also a tach sensor that attaches to this tach drive and I'm assuming that it converts the mechanical signal to an electric pulse. I can't tell you for sure if the HMMWV tach is electric or if there is also a mechanical version.

 

[nf6x]

I bought one of those tachometers a few years ago, but I haven't installed it in my HMMWV yet. I don't know which variants of the vehicle it goes with, but it wasn't a standard part on the first generation HMMWVs. That tach sensor in the HMMWV's vacuum pump drive hole is an electrical sender that is just connected to the diagnostic connector. I don't know yet if it's used by the tachometers being discussed here, or if they get their RPM signal some other way.

 

[nf6x]

Ok, I found some old pictures of the tach that I bought. I got it at a scrap yard back in 2007.

 

[donalloy1]

Outstanding reply's gents! Loks like I need to pursue Tachometer upgrade by another avenue? Want to go analog gage vs. digital that I have seen most here go for. The search goes on.

 

[Recovry4x4]

Additional questions related to the subject. The standard M series tachometers are mechanical. I've often toyed with the idea of trying to run one off of the tach drive the HMMWVs use. My delay is the vacuum. Once I change my truck over to the 700R4 I'm going to explore this route.

 

[nf6x]

Th HMMWV tach drive won't connect to a mechanical tachometer. It's an electrical sender. It's just a reed switch that's pulsed by a magnet attached to the shaft.

 

[Recovry4x4]

Mark, could there be 2 different styles? I really thought mine was a seperate part from the sender. Need to open up that dang engine can.

 

[nf6x]

It's been many years since I had the rear engine cover off, so my memory may be broken. Are you saying there's a normal tach drive adapter in the vacuum pump hole, and then the tach sender screws onto that? That sounds almost familiar now that you mention it. Hmm. I'd go look at it right now, but I'd have to pull the radio rack out to get the cover off.

 

[Recovry4x4]

That's what I'm thinking Mark. Don't go through the hassle of pulling the cowl, I'll open up a can in the next few days.

 

[patracy]

Cheapest and easiest tach is the tiny tach or for a little more a autometer mini diesel tach. The tiny tach has been discussed countless times and requires no calibration. It is a digital read out. The mini diesel tach uses a band around the alternator and requires calibration. (Either mathmatically with a GPS and/or very close speedo or a optical tach) If you choose this route, I have an optical tach I will loan you to calibrate it easy.

 

[Blue2actual]

have you considered a tiny tach? clamps on to an injector line, no calibration needed. http://www.steelsoldiers.com/cucv/85218-tiny-tach-installed.html

*edit-Patracy beat me to it!

 

[chevyCUCV]

The 89-93? Not really sure on years, but some early 6.5 civy diesels have a vacuum pump with a tach sender on it too i believe.
Not sure if it will interchange with the mil tach though, worth looking at the junkyard though