4x4 not working, auto nor manuall

[Lil willy]

ive seen posts all over saying that their auto 4x4 wont work, but their manually locking hubs work fine, well for me, its both... i got stuck today on a sand hill, and god forbid got pulled out by a gmc, but the thing thats bothering me is that when i put it in auto 4x4 the light comes on, but doesnt engage, 4x4 low does not work, but the low range light also lights up. if i manually lock the wheels, still nothing. i will lock the wheels, and also use the switch, and still nothing, although i heard a slight grinding noise in the front driver side wheel.. anyone experinced this same problem? if so, please reply how you overcame this fault. thank you.

[Young-SC-Owner]

your hub or hubs are not working. Ill bet the vac seals have failed. Inside the hubs may also be gummed up. I have Manual Lockers and after this summer one side gummed up a bit, so 15 mins a side, and some 2-4-C grease im good to go.

[Acidsniper]

^^ What he said. Sounds like the hubs and seals to me. The electronic shift on the fly relies on a vaccum system to engage the hubs automatically, you should hear a vaccum engage when you flip the switch, but since your 4x4 doesn't work in manual either I'd say it's the hubs themselves.

[Young-SC-Owner]

Yep, time to disassemble and clean

Sent from HTC EVO 3D Autoguide app

[Lil willy]

dissasembled, cleaned, re-greased, and put back together, working manually, had to put spacers in between the hub locker and hub internal for the hubs to lock completely. thanks for the help guys