NP435 walks out of 1st under power??

[jeepermc]

Not in my truck, but came out of a 2wd and went into my jeep. So why does it do that? Bad detent?? Haven't had to do anything to the 435's in my truck, but the one in the jeep I've had problems with since day 1. I even had the guy who adapted it to the 18 make sure it was all good when he did it. It's slightly noisy too in 3rd & 4th..... Also, there was a thread in here that said both trans & t-case should run 50 weight motor oil?? I've always run 90 weight gear oil in both........... Heep70??

[Jake11]

1st gear on the cluster is loose/wore out. Noisy in 3/4, countershaft
bearings. Use 90wt gear oil. You might look for another one. T18's are
good too, but I don't know if it would fit.

[heep70]

Per the manual you need 50 weight. Allot of folks run gear oil. The only difference noted was shifting is different and less noise. Oh, and slower drips.

[rjewkes]

my c6 auto does that when i kick it extra hard it may need a new trans mount and/or a bushing on the lever.

[jeepermc]

Thanks guys. I talked with the guy who did the t-case last night and the tranny was farmed out to someone else. His thoughts on the 1st gear were that it had a bad gear also. Didn't say much about the 3-4 noise, but was going to chat with the guy who did the tranny and see what his thoughts were on both problems. At any rate, looks like I'm going to have to pull it again one of these days...... I think I'll stick with the 90 weight in em.... Like you said, slower leaks....