Grinding noise in 4wd

[jp0863]

I've been experiencing a grinding noise while in 4wd, under hard acceleration when the tranny shifts. It also does it when going over an obstacle as the engine lugs. So I figure it ha something to do with the power going into the transfer case. I had a spare 241 laying around, swapped it in a few weeks back and it still does it... Which is what's causing the wtf moment...

Maybe out of adjustment? does it in 4hi and 4lo and only does it in 4wd.. Anyone have any thoughts?

 

[Deuling]

Id guess front driveshaft/axle issues if you already swapped a tcase.

 

[4xcrazy]

Last time mine did that, the trans mount was toast, when accelerating or power added to climb over things, the trans actually lifts up, I found the front driveshaft was actually rubbing the crossmember I believe it was.

 

[4xcrazy]

It was changing the angle of everything and rubbed right near the cv joint, I believe,, it's been a long time and took me a bit to find that problem, but now that I know the sound, I had it happen again while in Moab several years back, unfortunately, I was only part way through the triple trail run and ended up missing the next day because I couldn't get a new mount till morning, after everyone had already left for the runs, then I had to have the time to replace it... Sucked. I carry a spare now. :-P

 

[jp0863]

Well I can see the t-case move a bit, but don't see where it would be hitting to make a grinding noise....

 

[79HeavyChevy]

When my trans mounts went out it did the same thing, it laid over enough to rub the cross member with the outside of the cv joint.

But you could also watch the t case shifter move 1-1.5 inches to the right under hard acceleration.

 

[Blue85]

If it was just out of adjustment, you should be able to move the lever a bit and get the noise to go away. I have also experienced the sound of C/V joint in the crossmember, but only when the front axle was drooping. I would check out the U-joints, as they could make noise under load, but also look at your exhaust and everything around the driveshafts- could be hitting somewhere.

 

[jp0863]

I'll try swapping out the mount. U joints are new, and exhaust is way out of the way.

 

[jp0863]

That was it... Replaced the mount and even ground down part of the crossmember just to be safe... Probem solved, thanks for the advice and help!!