AW4 will not hold 1st gear

About a week ago I replaced my NSS for a new one and just noticed yesterday that my trans will no longer hold 1st. I have crawled under it and checked the shift cable its properly adjusted so I have no idea what going on. Is is possible that its the new NSS? is it an electrical signal that holds 1st gear?. My new NSS is not so hot, it did not fit on the shaft well and had to be tapped on and will not let my Jeep start in (N) just park. I plan on getting a warranty replacement NSS, but I would like to figure out why its not holding first gear while I am waiting on the new NSS.

what do you mean by not holding first gear

If I manually shift into 1-2 it will just shift on trough to 3rd. Before it would stay in 1st no matter the RPM.

jragan said:

Sounds as if you have a faulty NSS. Not starting in N just park would be first clue. See if it happens to start in R or D, this would point to wrong adjustment. Also AW4 should not hold 1st unless you have modified it, however when in 1-2 it will really rev before going into 2 and should not go into 3.

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I am planning trading out the NSS for a new one, I have tried to adjust this one but in either direction it will not start in ( N ) unless the shifter is just coming out of the detent.

It has always held first gear when shifted into 1-2 and if I wanted to hold 2nd I would shift to (D) and once it automatically shifted into 2nd I would pull the shifter back to 1-2 and it would hold 2nd until I shifted into Drive or the RPM s lowered enough to drop back into first. I have never had it shift out of 1st unless I moved it into drive. I use it when coming down ice & snow packed switchbacks for control. But it has never shifted up to 2nd on its own yet I have had it for 8 years.

OK I just went out and messed with it. I was wrong its not shifting to 3rd and it will shift between first and second gear but at really low RPMs. I put it in Low range and went down a steep hill and it will shift right out of first gear at very low rpms. So my next question is can I adjust it to where it will not kick out of first gear until a lot higher RPM?. Also while driving in second it will kick down randomly to first and rev the HELL out of the engine. It does this unpredictably.

Mine didn't hold first gear for a good while. Had the TCU behind the passenger side lower dash panel disconnected for a while with the panel out for a headlight switch problem. After I plugged it back in it started holding again. Bad connection or old TCU?

Not sure what it was that did it but I do not like it shifting into second on its own. So after a little research I put the second gear on a toggle switch. With the gear selector in 1-2 with the the newly installed switch turned "off" I am locked into first gear, with the switch turned "on" it will shift normally between first and second gear. I am now happy again and not fearing the upcoming seasons.