Ok there are a couple different posts on this but none really explain how to do it. I recently got into the hobby and I honestly have no idea what locking the differential actually means. I know what it does but not how to do it. So if anyone can give a step-by-step to guide me through the process it would be greatly appreciated. Thanks.

pull the diff APART AND FILL WITH jb leave diff open for a day or longer put back together and run it

id really like to know how this works too.
Just as a wild guess... would it involve putting slipper pegs in the diff gear instead of balls?

nope

Locking your diffs really arent a good idea, unless your only driving in straight lines 95% of time. If you lock your diff the truck will always push into turns, not to mention the strain you put on the drive train.
But if you insist on locking your diff i would just put a liitle dab of JB weld in your diffs to lock them up permenently. An alternative to this would be to use some Team Associated green slime or HPI diff lube to to slow down some diff unspooling.

Blah Blah Blah, lock the hell outta them diffs. My trucks diff. is locked and it hooks up way better in dirt. Who cares about street drivin.

hahah, locked diff worse control over truck open diff better control

A locked differential will do just what Richs said it will, push like hell. It won't allow the rear wheels to spin at different speeds, which is what a diff is supposed to do. I had mine adjusted a little too tight the other night, and it handled like crap. Unless you're only dragracing, don't lock it.

Captain Jack-

You can also use Silly Putty to lock your diff. The nice thing about it is that you can remove it to unlock your diff if you should choose to do so later. You would need to just clean out any oils or grease out of the diff before you put the Silly Putty in. It's a tested and proven method of saving yourself some money from having to buy new diff parts if you ever want it unlocked.

-RCT