95 ram 5.9 ext cab short box 4x4 build date 06/95 obd1 231d NP transfer case.

Transfer case chain was loose so changed out the chain and seals and all 5 ujoints including the yolk ball. Everything back together perfectly except now no odometer speedometer and stuck in limp mode in 2ndgear. OK vss bad on transfer case so replaced it, still bad ok faulty sensor so exchanged it still bad.... 4 supposed bad sensors later I'm stumped! Wiring is fine no shorts no breaks supposed to get 8v its getting 8.9v and you can put a sensor simulator to the wiring and everything works great but once you plug it into the sensor nothing. Gear on output shaft fine gear on sensor housing fine, you can spin the sensor by hand even and 0 response! HELP!!!! hall effect sensor also. Orange power black ground and white/orange sensor wire.

 

Is there a way to back probe the sensor while its connected? Maybe a pinched wire somewhere not detectable unless under load, or ground somewhere. I hate electrical problems. Just trying to throw out some ideas.

 

The VSS has to be properly 'clocked' on installation according to what color speedo gear you have. If it isn't, the gear does not engage it's drive gear on the output shaft, and the sensor simply doesn't work.

Your trans *should* be purely hydraulic. (aside from TCC, and O/D) Regardless of VSS function, the trans should still shift 1st thru 3rd. If it is stuck in second, you have another problem.

 

The gear on output shaft is blue. Gear on sensor housing (driven gear) is yellow. I've bench tested these also and no signal even if you spin the sensor by hand. Its a magnetic sensor it shouldn't need any extra attention to my knowledge. Yes I've probed the wiring its all fine. 2nd gear is limp mode I do believe.

 

I ran my 97 for a couple years without the vss on the transfer case hooked up. Only code I ever got was no speedo input. Never had any driving issues.
It sounds like your are having other problems unless the RH is that different from the RE.
As others have said, you have to make sure the vss is clocked properly. If it is in the wrong slot it either won't touch the drive gear, or it will be too tight and strip the drive gear. I know that one from experience unfortunately.

 

The RH trans (which you have) doesn't have a limp mode. That's only on the electronically controlled trans. (RE) The mechanical governor simply doesn't care what the speedometer thinks, or the PCM, it is driven by the trans, and regulates pressures/shifts accordingly.

Need to count the number of teeth on your driven gear. Apparently, the appropriate index mark (the marks have the number of teeth they correspond to stamped in the side of the VSS housing.) at the six o-clock position.

I am not sure you can spin the gear fast enough by hand, to get a reading...... (I just don't know.) An electric drill should do it though.

 

Been bench testing with a distributor tester. Believe me that thing spins it fast enough. The problem is literally between the pug and the output shaft which only includes the sensor itself and the sensor housing with the driven gear on it. Nothing is rounding off and its the same housing and gears that were in it to begin with I didn't f up there. All worked fine before dropped tcase and that was the only electrical component involved.

 

Where are you getting the sensors from, and what brand? It's *possible* you got several bad ones in a row..... but, the odds for that are pretty long.

I think you need to have voltage applied as well, for it to put out a signal.

 

Have a 12v supply going to it when on tester. Used a 6v at first. First one bad was original that worked before 2&3 bm from O'Reilly then one OE from dealership all 4 same results. The likelihood is slim to none but possible.

 

VSS wants five volt signal. Are you actually getting that at the sensor connector?