lately this winter when i am starting the truck even if it has been sitting for awhile and i start to go...there is a grinding noise...it sounds like it could be gears that are not latching together.

The noise will stop after high speeds or after awhile so at first i thought it was just water on the rotor....

Lately its been hapening more and more and when i stop it goes THUD THUD THD and makes the whole car shake with this LOUD noise.

Why i think its the hubs is because if i throw it into 4WD the noise will go away instantly...and when i shift out its fine for awhile.

maybe its time to grab some manual hubs...whos selling some?

 

The "hubs" on ADD are just splined flanges - no moving parts. Pretty much impossible for ADD HUBS to go bad.

If it really is the ADD not pulling back enough, manual hubs won't help. ADD works off of vacuum - make sure you don't have a vacuum leak anywhere.

 

Hmm that noise sounds somewhat familiar. Do you get a rattling noise at all coming from up there when you are driving slow like on surface streets? When my spindle bushing finally gave it up I was getting a nasty thump thump thump everytime I hit a bump and then finally it made this loud humming noise 5 or 6 times for about 10 seconds each time and then quit. This noise was the bushing itself spinning on the axle shaft. Crawl under your truck and grab your CV axle and see if you get any movement on the wheel side of it. Mine was pretty loose. If I put it in 4WD most of the noise would go away even when they were bad because it was putting a load on the CV axle. I had them spindle bushings replaced and it's solid now and no more mystery noises.

 

no movement in the CV at all...its sitting strong...


anyone else have ideas?

 

try this, are you leaving the vehicle in 4wd at nite and it gets really cold?

last time this happened to me, left it 4wd. woke up shifted out of 4wd and the noise what you are describing nearly scared the <bleep> out of me.

stopped, shifted into 4wd, noise is gone.

stopped, shifted into 2wd noise is gone and drove home. that was like 5-10 years ago...