ratcheting sound when under heavy load

[Captn. Crunch]

My buddy got his dump truck stuck in my yard yesterday so We hooked a tow chain to the hitch on my AWD Safari to get him moving. My wheels were all on soft dirt and when I gave it the gas a not too pleasant noise eminated from the underside of my truck. It was a ratcheting kinda noise, I backed off-hit it again pulled the truck free, noise didn't repeat. Transfer case chain? Rolling over spines on a shaft? This sound familiar to anyone?
Any excuse for an upgrade!!!

Thanks

[doyoulikeithere]

Thats awesome that you pulled out a dump truck that was stuck
Nice !
I'm not sure about the sound though.
I've heard a ratcheting kind of sound like that before, and that was when I was in an Oldsmobile being rope towed by a truck. It wasn't running, and had no brakes.
Anyways I put it in park while it was still rolling, and it didn't come to screeching halt, instead it made a distinct ratcheting sound, and kept rolling along.
So, I'm wondering if when you put it into gear to go, instead of engaging properly, your trans actually made that same ratcheting sound which I assume must be some kind of a safety mechanism to avoid breakage if it isn't in gear properly, or is rolling and shifting to park or something?
I bet the first thing you did was run the shifter up to R and then down to D then try again eh?

[Captn. Crunch]

It was only a mason dump but it had a load on it and yes-it was awesome!!! I know the sound your talking about, it's the parking pawl, the same bugger that makes it hard to get out of park after parking on a hill. The sound was similar but more urgent if you know what I mean. I was already in low and rolling forward taking up the slack in the chain. He yelled "hit it" and I did. The truck sat down and started pulling hard almost no wheel slip and GRRRRRRRRRRR. I lifted and hit it again and we were good. The S.O.B. that sold me this truck said he had the transfer case re-built by a pro, but his word doesn't hold much weight with me anymore. Not after the steady stream of parts that I've put into it since buying this "well maintained" van.

[doyoulikeithere]

Maybe you should look for a good used NP241.

[Captn. Crunch]

Here is an update to close this old thread. I could have sworn the noise was something slipping in the drivetrain. You could feel it through the steering wheel, it changed along with engine rpm and it only happens when you really romp on it. What was actually happening was two worn out idler arms were allowing the center link to rotate it and contact the harmonic balancer. Two Moog idlers later all is well

[Cobra]

oh so it was actually a steering problem I believe Lifted had a similar problem while wheeling, his center link would flex up into the harmonic balancer. I think he said it threw sparks too lol

[LiftedAWDAstro]

Yup. Sure did throws lots of sparks!