1998 Tahoe 4x4 issues

[Mark Moore]

I have a 98 Tahoe . The 4 low function was not working. So I read you need it to be moving about 1mph and to be in neutral before hitting the 4 low switch . I did that and still nothing. Now I don’t have any trans at all ! It won’t go into park or any gears even reverse . I can here the front 4x4 actuator work when I press the switch but still nothing. Do any of you have any ideas of what I could check ? Thanks for any input.

 

[EppNation]

I have very similar truck and I've always thought you had to be stationary (and in neutral) to engage, but could be either stationary or rolling very slowly (and in neutral) to disengage. 'Very slowly' being a very slow rolling idle, less than 5mph.
This is how I've always operated mine without issue. Every oil change I drive it out to a field and cycle through both 4Hi and 4Lo for a few hundred feet to keep everything in front dif lubed up.

Are you saying that upon hitting the 4Lo button, whilst moving slowly and in neutral, now your truck has no ability to engage any gears at all, and shifter won't go into park?

Remember: avoid using 4x4 on any kind of pavement, even just for brief testing/diag purposes. Find a field.

 

[GTO3x2]

I know the same as EppNation (above) for the floor shift type. Also I recall needing to do it swiftly and you also have to go all the way through with the lever, and it seems to an amount that is a stretch more than expected.