4wd issue

[jay menna]

i hava a 2002 dmax 2500hd when the the truck is in 4 wheel drive it feels like it is binding up. their is a banging/clunking noise when you turn the wheels or first step on the gas.i changed both diffs and transfer case oils. i thought it was the cv shafts. so i replaced them both. one was gone the other was still good. changed it anyways. problem didn't go away. this past weekend i was plowing and it was doing it alot and getting worse. any suggestions on what it could be.

[Mark Rinker]

Are your diffs open or limited slip? I haven't had this issue with either of my trucks while plowing, but wonder if maybe the 'bind' is improper lubrication in the diffs. That is where the difference in rotation between left and right tires during powered turns happens.

Way back in the day there was a special GM additive for limited slip rearends. Haven't heard anything about it for decades. Maybe one of our GM techs will chime in here...

Also - are your wheels/tires stock size or...?

[jay menna]

it happens even not just when plowing but in 4wd driving. iam not sure if the diffs are limited slip or not. was there an option in 2002 on the diffs. my tire size is 285 75 16. but it did this when i had the 265's on it. i had a 98 6.5 1500. i had similar problems. it was the main bearing in the front diff. do you think this could be the case.

[DA BIG ONE]

If not stocked size tires maybe needs VSS calibration.

Another though, I've seen frt/rear diffs w/different ratios frt/back after some bone yard parts were used, suggest you check both ratios if not origional owner.

I have a air locker front diff which only binds on hard surfaces.

[madmatt]

I had an Esclade come in the shop once w/ a problem resembling yours. after driving it around and getting it on the rcak w/ the front drive shaft removed I found a lot of wiggle in the pinion. Pulled the diff and found the pinion and bearings shot. I replaced all the bearings and the ring and pinion and she was good as new. I know this is a AWD vehicle and only 1/2 ton drivetrain is used but it is still pretty much just a down sized version of yours. I'd give the front pinion a good shake and check the u-joints. I also had a 1/2 ton binding and jerking another time and when I lifted it the front left wheel nearly feel off due to the hub being so jacked up.