Smart guys: What is the output signal from the Tcase speed sensor?

[mooktank]

I'm ripping out the entire driveline from a '95 sport and replacing it with a Cummins B3.3, AX-15, and NP231. I was wondering what the voltage output would be from the speed sensor in the tcase. There are three wires correct? Supply power, ground, and signal?

The jeep Tcase has the same 3 wires but is driven by a gear. My '97 5.0 ex has a gear driven sensor while it looks like the 95 has a hall effect sensor. Would it be possible to use the jeep sensor or would the 97 sensor work? I know I could machine an adapter to use the gear driven piece from the '97 and as long as the signals were equal my speedo would still work correctly.

I can't really find any good info on this so I'm helping someone has some valuable knowledge.

 

[BrooklynBay]

I would recommend getting the same sensor. The output signal varies with the speed of the vehicle, so both might have different specifications. The gear ratio also varies the output with the speed at which the gears turn.

 

[mooktank]

Right... but I'm not changing the rear end so gear ratio is technically not changing. I'm assuming the output is at least fairly linear?

I can't just slap the 95 ex sensor into the jeep case there are no magnets there for the hall effect to work unless I implanted the magnets on the outputshaft at the right radius. I don't think that will be necessary.

I guess the big question is whether or not the 97 5.0 ex has the same speedometer as the 95 4.0... If they're the same I can just slap the 97 gear driven model in there and be done with it (which is what I did to put an NP205 in the 97)

Anyway, thanks for the input.

 

[BrooklynBay]

When I was referring to the gear ratio, I was talking about the amount of teeth on the VSS color coded gear. There is also a gear within the transfer case. Take a look at my other thread on speedometer gears: http://www.explorerforum.com/forums/showthread.php?t=158739. This is # 3 in my list of useful threads.

 

[mooktank]

Ohhh I gotcha now. I was looking at the tcase I had on my old 97 sport with a 4.0 and the control trac case and it didn't have a gear on it. Do the 95s have gears? If so, I should be in business as I know I can get the jeep case to turn that gear.

 

[BrooklynBay]

According to this thread: http://www.explorerforum.com/forums/showthread.php?t=146122, it says that the gear was used until 1997. As far as other Fords such as my Aerostars, my 89 has the VSS sensor on the extension housing, but does not have the speedometer cable since it has a digital dashboard. My 93 has a sensor on the rear differential which is different than the type with a gear (Hall Effect).

 

[Cobraguy]

I'm ripping out the entire driveline from a '95 sport and replacing it with a Cummins B3.3, AX-15, and NP231.

You're doing WHAT?????

By the way, the speedometers for 95 and 97 should require the same signal. I believe it was in 98 and up that the speed sensor went to the rear diff (same as ABS sensor) and utilized a different signal pattern.

You actually might want to look at 410Fortune's link for converting transfer cases. He dealt with having to install the proper VSS in a transfer case that didn't come with what he needed.

 

[mooktank]

Solved!

Okay, I solved this issue and thought I'd post up the knowledge...

The jeep speedometer spins at the same ratio as the ford. All I had to do was machine this adapter from Nylon to mate the two together. If you notice the small square male part of the explorer sensor fits right into the shaft the jeep gear is mounted on. So far my speedometer works perfect!