Since this thread came up as the #1 result of a Google search for "adjusting Smittybilt Atlas Bumper" I figured I'd revive it and add some information.
One thing I've noticed is that over time the swing gate will sag. This is inevitable given the amount of weight and the forces upon a very small mounting surface (the pivot). As Archimedes is famously reported to have said "Give me a lever long enough and a fulcrum on which to place it, and I shall move the world." The fulcrum in this case is the pivot point and represents the greatest possible mechanical advantage (or disadvantage from our POV) against the mount. Thus there is a lot of force pulling down on that pivot when the gate is not resting on its latch.
Anyway, what this all means is that just like a big heavy garden gate, you have to periodically adjust this thing to compensate for the sag.
There are two common issues: (1) interference/rubbing between the swing gate and the bumper and (2) the latch not operating well (binding, hard to open or close).
My approach is as follows:
(1) If you're having problems with the swing gate hitting the bumper, then you can try just cranking the cam adjuster up a bit with a 3/8" ratchet. You may or may not have the set screw pictured (mine doesn't have one). Just remove the 4 Allen head screws on the billet cover to expose the adjuster:
(2) However, if you had to crank the adjuster up a lot in order to clear the interference (or if there is plenty of clearance between the swing gate and the bumper but the latch is not operating well), then you will need to adjust the entire assembly. This can be a bit tricky because it moves in two planes (up/down and fore/aft) and the striker pin can move in and out. Trial and error is often required and you might make it worse before it gets better.
If things are close and you don’t have interference issues, you may only need to adjust the latch plate.
a. Loosen the striker pin and move it all the way UP as high as it will go (there isn't much adjustment). Use Loctite on the threads.
b. Adjust the cam so that the latch lines up with the striker pin, but about 1/8" below center (so that when it is engaged, it is supporting this side of the gate). (You'll fine-tune this later so it doesn't have to be perfect.)
You also need to check to make sure that the striker pin is centered between the teeth of the latch (the "in-out" dimension, if you will):
In this picture you can see that the striker pin needs to move to the left (or "out") in order to engage properly. If you have this problem, you need to shim the striker pin with a washer.
c. Making the adjustments:
The best method I've found is to slightly preload the swing gate (I'll use a shim on the bumper) so that it is being lifted about 1/8" above its natural resting position. (This takes up the "sag" in the pivot).
Then adjust the latch plate so that it lines up on the same vertical plane as the striker pin. Then mark the top and bottom position with pencil and tighten the latch plate and test fit. If the latch plate is centered on the striker pin but not engaging properly (either falling short of the catch or engaging to deeply), then move the latch plate fore or aft as required, being careful to keep it lined up with the pencil lines you’ve drawn. In my experience this is the trickiest part.
Finally, for 80% of the people out there with latch problems on this swing gate, I'd bet that a liberal dose of something like lithium grease or a good thick lubricant on the striker pin and latch plate and some CLP or Ballistol on the inner mechanisms will resolve issues.
To summarize:
If you have issues with the swing gate rubbing against the bumper
- Adjust cam
- If necessary, adjust latch
If you have plenty of clearance, but the latch is binding:
- Adjust latch plate, ensuring that the teeth are centered both fore and aft and up and down but also “in and out” using or removing washer shims if necessary.
If you’re having issues with interference, AND the latch is way out of whack, you may need a full “reset”:
- Loosen striker pin and move all the way up (use Loctite on the threads)
- Adjust cam so latch is centered on striker pin
- Fine tune latch plate in all 3 dimensions