Im not much of a drivetrain tech, more engine diag guy and
so forth. Have a 99 sonoma here when driving in 2WD truck
runs great. Switch it into 4x4 and once about every 10
seconds while driving there is a very severe BANG. It shakes
the whole truck and continues this until switched back into
2WD. The truck sat for about 2 years and is just now on the
road again. All fluids are good. The 4X4 works while the
truck is in the air on the rack and there is no noise with
the wheels off the ground either. Everything sounds nice and
smooth when in the air. Any help would be great.


3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)

Potholes


“Poor Al Gore. Global warming completely debunked via the very Internet you invented. Oh, oh, the irony!” -Jon Stewart

you might try S10FORUM.COM in the 4x4 section

Sounds like the gears in the transfer case are binding up. How are your tires? All 4 the same size? We had a blazer blow the rear, do to it having different size tires on it. The fronts were spining faster then the rear causing the gears to bind up and over heat. Eventually the heat and to much pressure caused it to blow. It had the same symptoms before the rear went. Loud bangs and would shake like crazy.