:confused: 1997 tahoe AT / 350 4x4. NP 241c transfer case.
Grinding noise comes from transfer case on acceleration. Can hear and feel noise coming from selector lever on the floor. Removed front drive shaft and noise still comes from lever. Grinding gets worse on acceleration, letting off, or yanking it into 4 hi stops the noise. Also discsonected the wires to the front axle. When all 4 tires are off the ground it won't do it, no load on the drive train I guess?
Seems the problem is transfer case or tranny, how do I tell which one? Haven't checked the u-joints real well but wouldn't think it was them since engaging 4 hi stops the noise.

Please Help Me.
Reese
remspeed@adelphia.net

i dont know if the 241 has this same design the 231 has, but it may. I made a big mistake and bought a new transfer case, when a $.35 part was broken. what happened on mine is that a clip poped off in the tailshaft and caused the shaft to slap around. I woudl have someone check it before it does any damage.. but it just oculd be it.. and shoudl be about 2 hours in labor, $0.35 for a new clip, and about $5 for seals.

hope i helped. Garrett

Make sure you check the slider engagement. I bet that either the detent is not holding in the shifting collar in the right spot anymore or that the collar has come off of the fork inside the transfer case.

My friends push button transfer case did this and it would only due it under braking. Same thing though.

Thanks for the advice I'm tearing into it this afternoon, but it seems like it is doing it less now and I'm tempted to let it ride for now. If the collar slipped off I'm wondering if it could slip back on. Can't get it to make noise today with out moving floor selector around. just to see if it aggravates it I'll tow my race car trailer around.

Thanks, I'll post what I find out.
Reese

From my experience you have 1 of 2 failures. Most likely the first.

1. The little plastic pads on the shift fork for either the 2wd/4wd or the hi/lo fork have either failed or come loose. This allows movement in either of these parts and can cause internal parts to come into contact. Most likely the grinding is coming from the shift fork wearing into the hi/lo mode shaft.

2. A bearing or pump is going or gone. I don't think this is very likely as it wouldn't get better, it would get worse really fast.

The 241 is pretty simple and there aren't a lot of parts to go bad. Most failures are a result of running low on oil.

As for the collar slipping off that was mentioned earlier. The collar or mode shaft is held in place by the little plastic pads. The collar will not actually come off unless it's worn through or the main shaft bearings are shot.

Thanks for the help everyone. After removing the transfer case I found the pads had come loose and the fork was jumping around causing contact of the 4 hi engagement.