Does anyone know how to engage the front axle so you can go from 4WD to AWD? In theory i would think if you put your truck in 4WD (manual **** T-case) then remove the t-case and front driveshaft and install an NVG149 and SS front driveshaft it should work.

Anyone wanna chime in on this?

 

If I understand your question correctly, it’s not really a big deal if you find the appropriate components. The center section of the 8.25” differential is the same between the 4WD and AWD units, as well as the driver’s side stub axle. Where things become different is the passenger side, the AWD units have a one piece axle and a axle tube not equipped for the engagement fork, where as the 4WD units have a two piece axle and the fork. One can swap the components from differential to differential without any issues. The commonality between the two differentials is actually a good thing for those of us with the AWD units, as finding good replacement parts is fairly tough, but there 100’s of thousands of 4WD’s begging to donate their parts. The funny thing is I’ve only seen a couple of folks take advantage of this commonality, most end up searching high and low for a good replacement AWD differential, when it’s unnecessary.

 

so where would you find that passenger side axle tube?

 

Any GMT-800 AWD equipped vehicle, such as the GMC C3, Sierra Denali, Yukon Denali, Cadillac Escalade and Silverado SS. You do have choices, it’s just when one goes to looking for parts the 4WD equipped vehicles way out-number the AWD units.

Also, besides the axle tube, you would also need the one-piece axle for the passenger side.

 

So to make this swap complete, I would need the passenger side axle tube and one piece axle?

 

okyou kinda just threw me off...

i thought the axle tube was all i needed

 

Reread his post, you will understand what you need.

 

i thought the axle them self would be the same? guess not. my problem is i have a 97, im not sure if the front diff on GMT8oo trucks will bolt into mine

 

They are basically the same, with the axle tube and passenger side axle being the exception I guess.

 

Happen to know the GM part numbers for them?