HeavyCal

I've had this happen twice now and it's unnerving to say the least.

Normally I drive in 2WD but during rain (or when I feel like doing a launch) I'll use 4A or 4HI. The first time it comes out of 2WD and under acceleration (extra emphasis cause my thread title is a bit misleading) there is a VERY nasty clunk that comes out of the front end, and then nothing. If I switch it back to 2WD and back to 4 I don't get it again. Drives normally, no other noises or issues. It's like the system has to be in 2WD for a while before doing it again.

This only occurred after my lift was installed. I've done a cursory inspection of all the front end components and everything seems fine, nice and tight. I've just been way too busy to call the shop that did it and inquire, I'll probably do that next week. In the meantime if anyone has ideas on what this could be I'm all ears.

TexasRedfish

That's sounds about right to me. If I haven't engaged 4wd in a while sometimes it makes a clunk when engaging and disengaging. But if I'm on my trails and switch between 2wd and 4wd the clunk is lessened or doesn't even happen. It's more noticed on pavement. But if you don't notice anything else I'd say you're fine. If not, whoever installed you lift should cover a little while after install.

odd-6

Are you switching while under throttle? That can make a nasty clunk

HeavyCal

Sometimes yes. Glad to know it's likely not anything serious, just never noticed that on my GMs. I will check with the shop and dealership just in case. Thanks for the posts guys!