Dakota Digital RTX Speedo Sensor Install Question (1 Viewer)

[Will Van]

I am finally getting around to installing my Dakota Digital RTX system in my 40 series. I have an H55F and Toyota twin stick split case from a 60 series.

The kit is supplied with a 7/8"-18 extension cable, presumably to adapt the Dakota Digital electronic speed sensor to the Toyota transfer case.

However, the Dakota Digital speedo sensor threads directly onto the Toyota transfer case without the extension cable. Is there any reason why I can't just thread the DD speedo sensor directly into the Toyota transfer case? I pulled the part number on the DD extension cable (130011), and it is the exact same threads on both ends 7/8"-18 male and 7/8"-18 female. Am I missing something here?

Or do I need to include the cable?

 

[Will Van]

I called Dakota Digital this morning and they were not much help. They said that the cable extension offers more "bite" on the t-case speedo flange, but did not seem very confident in their answer.

They suggested I just try out the sensor directly on the t-case, and if speedo doesn't work, then add the cable extension.

@Gotta be Geared, @SMG, @shmukster, @UZJ40, @TCSTARK, @Snowdogyyz - Any insight?

 

[lelandEOD]

I don't know the answer but I encourage you to give it a try! I don't like the extension cable at all and would love to delete mine, if it is possible to get away without it.

Keep us posted!

 

[SMG]

My advice is buy their GPS module and be done with all the cables.

 

[Will Van]

My advice is buy their GPS module and be done with all the cables.

Do you simply cap the port for the speed sensor/cable? How do you like the GPS module? Can it be mounted anywhere in the truck?

 

[SMG]

Yes, that’s what I did. I turned a small piece of stainless for a cap.
Yes, you can mount It anywhere. Mine was in the glove box. You can also buy their extended antenna, but mine worked fine. Basically, plug and play. Worked great!

 

[Will Van]

Yes, that’s what I did. I turned a small piece of stainless for a cap.
Yes, you can mount It anywhere. Mine was in the glove box. You can also buy their extended antenna, but mine worked fine. Basically, plug and play. Worked great!

Roger that, thanks for the intel. I will consider the GPS solution.

 

[lelandEOD]

I have the GPS and don't really feel it's a total replacement for a speedo sensor. Granted, it's handy as hell for calibrating the speedo, has a couple cool features (compass and altimeter), and has software and accelerometers intended to smooth out intermittent reception interruptions (tunnels, overpasses), you will find it irritating if you frequently drive in areas with poor GPS reception. When I tried it up in the mountains, the GPS speedo function would frequently get "lost". YMMV.

 

[lelandEOD]

... I also wonder why you received a different looking speed sensor than the one that was included with my HDX package?

Mine looks like this:

 

[Will Van]

I'm still not sure why the cable extension is added to the kit, because the threads are the same on both the sensor itself, and the cable extension, but I did a little more research and found out a bit more information.

The speed sensor and cable extension supplied with the Dakota Digital kit is threaded 7/8"-18 and is "designed to fit all GM transmissions."

However, the threads on the Toyota transfer case are not 7/8"-18. They are metric - 22 mm x 1.5 thread pitch. Obviously the SAE and metric threads are very close, because the setup works. But it's technically not correct.

This is consistent with the remainder of the adapters and fittings supplied with the DD kit. The water temp and oil temp sensors supplied with the Dakota Digital are 1/8" NPT male. The instructions call for placing the oil temp sensor in the Toyota oil filter tree, and that you "may have to deepen the threads with a tap." But the oil filter tree is threaded 1/8" BSPT, not NPT. You're not deepening the threads, you're re-threading it for NPT. Which only works because BSPT threads are 55° and NPT threads are 60°.

Same for the water temp sensor - The Dakota Digital kit comes with 12mm, 16mm, and various NPT bushings, but the water ports in the head of the 2F are 1/2" BSPT. Yes, a 1/2" NPT to 1/8" NPT adapter fitting would probably work, but that particular adapter is not supplied with the kit.

At this point I am not exactly sure what I am going to do. There is a Trail Gear Mechanical to Electrical speedometer sensor available with the correct M22 x 1.5 metric threads for the Toyota t-case, but I'm not sure if the sensor is compatible with the Dakota Digital electronics.

I'll probably just direct thread the supplied DD speed sensor on the Toyota transfer case and see if it works.

And that my friends, is more than you ever wanted to know about Dakota Digital sensors.

 

[Will Van]

... I also wonder why you received a different looking speed sensor than the one that was included with my HDX package?

Mine looks like this:
View attachment 2178607

No, that's the old style. I have the new style.

 

[hey you]

Updates?

 

[Will Van]

Updates?

I just installed the supplied extension and quit agonizing over it. Works great.

 

[hey you]

Thanks! I was also wondering if the wiring to the oil and water sensors couldn't be attached to the Toyota sensors? Or, do you have to use the supplied Dakota Digital kit sensors?

 

[Will Van]

Thanks! I was also wondering if the wiring to the oil and water sensors couldn't be attached to the Toyota sensors? Or, do you have to use the supplied Dakota Digital kit sensors?

You need to use the supplied Dakota Digital sensors since they are modern electronic.

 

[hey you]

Thank you! I'm going to pick up a VHX for my FJ40 in January. I have the Orion transfer case behind an H41 transmission.

 

[Will Van]

Thank you! I'm going to pick up a VHX for my FJ40 in January. I have the Orion transfer case behind an H41 transmission.

Nice!

The Dakota Digital vendors on this forum are much more knowledgeable than me on these topics. If you have any issues, you should reach out to them.

 

[Curtice]

@Will Van got any installed pics of the gauges themselves, how you mounted the switch, etc?

 

[Will Van]

@Will Van got any installed pics of the gauges themselves, how you mounted the switch, etc?

I just mounted the switch with double-sided tape on a tab below the radio DIN.

Disregard the dangling wires below the Dakota switch. It’s the idle-up control wiring from the Holley Sniper for air conditioning (that I have yet to install).

 

[Will Van]

The red “4” above the 60MPH script is the redline indicator I programmed into the unit. In hindsight, I should have ordered a custom RPM scale from 0 to 5,000 (instead of 8,000 on the Dakota out-of-the-box). That would place the red “4” closer to above the 100mph area and utilize the whole RPM sweep.