shifting noise

[H3nightrod]

So after a short run at badlands this weekend I noticed a different sound coming from my front end. I don't remember ever hearing this so i'm worried that something might be close to failure. Hope you can give me some ideas on what it might be. I noticed that when in neutral when I switch from 4 high to 4 low there is the normal clicking sound under the truck, but even with my foot firmly on the brake there is a loud banging sound when I shift into drive.

The bang sound sound like its metal in metal. I tried it at the parking lot and it happens exactly when I shift to drive not while going from high to low. is this the beginning of a transfer case failure or front axle?

my h3 is an 08 alpha with no front locker. Have about 58k leveled and running on 35s.
Thanks for the help.

 

[06 H3]

could it be your crossmember bushing? seeing when you go to put it in drive it has the added load on it so it may make it more apparent then

 

[alrock]

Easy to figure if it is the crossmember bushing out if you have one more person. Have someone look under your truck as you shift it from Park to Drive, or to Reverse, or any combination like that. Look for the front diff to rock back and forth. With a good bushing the movement is nominal but with a bad bushing the diff will move significantly.

I think you're probably looking at a small fix, not a big one.

 

[H3nightrod]

I'll crawl under it tomorrow.

Does it make any difference if it only does the sound on the first shift to drive and no noise when going reverses to drive or drive to reverse?

 

[alrock]

I've seen it manifest itself in different ways as I've gone through about five of those crossmembers. Severity has been different depending on the type or progress of the breakage. For example, one time it was mostly putting it into reverse that it occurred. For Bigunit, he broke the bolt and the diff was rocking back and forth constantly on any bump, change in acceleration, etc. Heck, you might even be able to move the diff by hand (with the engine off of course). If "normal" the back end won't move but a tiny bit, as much as the rubber bushing allows absorption of vibration. My guess is that you'll be able to move the diff up or down to hit the body or the crossmember.

 

[sinstr]

Im with Alrock on this, check the front crossmember. The first time mine failed, it was not noisy but i could feel it when starting or stopping. This last time, the bushing bolt backed out, and it was making so much noise I left my truck 250 miles away thinking I grenaded the front diff. Ive seen 3 of these go now, and no two sound alike.