Awd

[PitchBlackC3]

I dont think the axles are holding the tires on... thats what lugnuts are for,no? idk
and about the transfercase,that makes some sence. i have a 2wd tranny laying around maybe i can just swap em

Well the axles, don't hold the wheels on, but they do hold the preload on the wheel bearings. They will not last 10 miles with the axles out. You can take the end shaft out of the CV axles and leave them bolted into the bearings or use 2wd bearings.

The transfer case will transfer 100% to the rear with the 149 without the front diff. It will work fine as a 2wd, but it will ruin it for AWD.
If you swap in the 2wd tranny you will have to do something about the driveshaft length, the 2wd ECSBs all use a 2 piece shaft with a carrier bearing.

[zeake]

Well the axles, don't hold the wheels on, but they do hold the preload on the wheel bearings. They will not last 10 miles with the axles out. You can take the end shaft out of the CV axles and leave them bolted into the bearings or use 2wd bearings.

The transfer case will transfer 100% to the rear with the 149 without the front diff. It will work fine as a 2wd, but it will ruin it for AWD.
If you swap in the 2wd tranny you will have to do something about the driveshaft length, the 2wd ECSBs all use a 2 piece shaft with a carrier bearing.

I could not remember exactly what the deal was with the front. It will kill a 149. You could still drive around but the tc will die. Cheaper and easier to just replace the front diff. If your transfer case is not a 149 it won't transfer power to the rear end. Some transfer cases use the computer and brake control to transfer power to front and rear. Check to see what transfer case you have.
For what its worth I bought a front diff for around 400$

[PitchBlackC3]

Zeake is right about the Borg Warner transfer cases not transferring torque without the drive shaft. That's why I asked if it was a Sierra or Yukon. 2003 Sierra Denali would have the 149.

Yes, I would replace the front diff as well, like I said in some of the other threads you can adapt a 4x4 front diff for use in the AWD and they are dime a dozen.

[gTeran1]

i guess i should update

too the axles off and diff down,opend it up and everything looked fine......
put everything back togther and its still making the clunking noise.i asked my brother to put it in D and stand on the breaks and hit the gas.
the driveshaft that goes to the rear wheels pops in and out alittle bit enough to make the clunk...idk what it can be now
transfercase? tranny?
i had the tranny re-built about 3 months ago.and when i would go to WOT on 1-2 it made a LOUD bang and would go into neutral and when the rpms came back down the tranny worked fine.
how do i know what t-case i have?

thanks guys for helping me out

[gTeran1]

Ttt

[PitchBlackC3]

You have a 149, that's the only one that came in the 2003 Sierra Denali.

[gTeran1]

You have a 149, that's the only one that came in the 2003 Sierra Denali.

can i put a 208 on it?