If the grease smells burnt, it sounds like you need to have a look at your wheel bearings. After the lock out cap is off, take the internal snap ring out of the hub and pull the locking mechanism using two of the lock out cap bolts. Then you will have to have a hub nut socket to get the lock nuts off. Once the first nut is out, there is a ring that you have to use a pick to take out then another nut behind it. After that is out, pop the top of the rotor with you palm and the outter bearing will pop out. Put the inner hub nut back on and drag the rotor down the hub till you feel the inner bearing hit the nut. Slip it back a bit and pull very hard on the rotor outward so that the inner bearing and seal are popped out of the rotor. You can now clean everything and inspect them for damage. Remember, DO NOT PACK THE HUB FULL OF GREASE, only pack the bearings. The bearings only use the grease you pack into the rollers. All that open space in there is for cooling purposes, filling it full of grease causes the hub to hold much more heat and damage the bearings. I've been servicing wheel bearings since I was 12 and my Dad, who taught me, since the 60's.
As for the lock out, a new set of Warn or Mile Markers isn't much, bout $50 I think.
Terry
1999 K1500 Suburban
1984 K5 Blazer
Wanna-be explorer living vicariously through the travels of others.