4LO noise
 

Ok call me crazy on this one- but is it normal to hear a loud "clunk" noise when going into 4LO from 4HI with the truck in neutral and stopped (I always put it in neutral when going into 4HI/4LO and I usually do it while rolling very slow, but not this time because it was in the garage after going up our driveway after a snowstorm.)? I normally just hear and feel a soft "clunk" coming from under the truck along with the loud, smooth and clear encoder when shifting into 4HI from 2HI (truck goes in and out of 4HI and 4LO with no problems, with the 2HI-4HI shift being instant and so fast the 4HI light doesn't have time to flash and the 4HI-4LO being fast, but not as fast as 2HI-4HI.). It is when putting it in 4LO which is the issue here. Also when I go to put it into Drive, the whole truck jerks forward and sometimes makes another equally loud but differently sounding "clunk" when the tranny goes into gear like 1 second after the lever hits the "D".

Also IDK if this matters, but I had the transfer case fluid changed last summer and had the level checked a few months ago and it was overfilled, but they let a little bit out and determined it was okay. I don't know of any leaks except for old engine oil around the engine after having the oil cooler lines replaced in October (maybe another leak somewhere, but it isn't losing oil).


Is all this normal and I am going insane or am I perfectly sane and there is an actual problem forming?

Also the "SERVICE 4WD" light doesn't work on my dashboard, so I don't have any notification of any possible ELECTRICAL problem with the 4x4 system. We have already had the shift fork in the front axle and the TCCM replaced within a month of each other during the 2007-2008 holiday season and then a 3rd failure after GM put a 10A fuse in the 20A encoder circuit (they tried to fake another 4x4 failure so they make more $$$, but I caught it and put the right fuse in and it worked fine ever since!!)

Thanks

BD

Mine makes the big clunk too going into 4LO. Going from 2HI to 4HI or 2HI to 4 Auto I can hear a small clunk from the front end but the transfer case is quiet so I just assumed it's from a few extra gears in the reduction.