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Poison Spyder 4-Door Frame Mounted Rocker Knockers

Poison Spyder makes Rocker Knockers in two different flavors: frame-mounted and body-mounted. Both are made exactly the same except in how they attach to the Jeep. The price is also the same between the two options. Both have a tubular rocker rail made from 1.75″ X .120 wall DOM and a slider rail, fabricated from CNC-bent 1.5″ X .120 wall DOM tubing. The space between tubes is filled with a 3/16″ thick CNC laser-cut plate and is covered by a unique oval dimple die cut removable skin. Rocker Knockers keep rocks and obstacles at bay while off-road protecting the doors, tub and paint. Frame-mounted and body-mounted Rocker Knockers have their pros and cons, but the decision between the two was a simple one for me.



I like that the body mounted Rocker Knockers sit higher on the Jeep’s tub and provides more ground clearance. However, they use nutserts to attached to the sheet metal. I hate nutserts, they are a pain in the butt. If I was running a long arm kit I’d probably have to go with the body mounted variety. Most long arm systems use the same mounting location as the frame mounted outriggers. Since the Poison Spyder Frame Mounted Rocker Knockers attach directly to the Jeep’s frame rail, the Jeep is better protected from side and vertical impacts. I have no doubt this will hold the entire weight of my Jeep if it comes to that. My only concern with the outrigger design of the frame mounted version is their tendency to hang up on obstacles. But, that’s why we have a skinny pedal. I’ll take that chance to avoid nutserts. Did I mention I hate them?

Buying Experience

I bought my Poison Spyder Frame Mounted Rocker Knockers from Northridge 4×4. They arrive quickly and well-packaged. However, I had one issue, I received 2 drivers side skins and no passenger skin. It was assembled upside down so it appeared correct from a glance but the oval dimples pointed out. A quick phone call to Northridge along with a few photos in an email and a new set of skins were on their way. Northridge has great customer service, not to mention free shipping which can’t be cheap to ship heavy Jeep parts from the west coast to Missouri. PSC sells replacement skins that come with new hardware, that’s what I received to complete my purchase. So, I now have 3 drivers side skins, one passenger side skin and 2 sets of hardware—score. I have a backup for my back on the driver’s side. Any bets on which side gets damaged first? I’m a fairly lucky guy but I’m a firm believer in the principle, “two is one and one is none”. Only time will tell.




Installation (and marketing) video from PSC

Parts List:

  • Driver side JK Rocker Knocker, Frame-Mount
  • Passenger side JK Rocker Knocker, Frame-Mount
  • Driver side skin
  • Passenger side skin (grrrr)
  • (1) 1/2” ID X 1-1/4” OD X 3/16” thick spacer
  • (2) 1/2-20 X 1 Gr. 8 Hex Head Cap Screw
  • (2) 1/2 Gr. 8 Flat Washer
  • (4) 3/8-16 X 1-1/2 Gr. 8 Hex Head Cap Screw
  • (2) 3/8-16 X 1 Gr. 8 Hex Head Cap Screw
  • (6) 3/8-16 Gr. 8 Nylon Insert Lock Nut
  • (12) 3/8 Gr. 8 Flat Washer
  • (2) M12-1.5 X 40MM Hex Head Cap Screw
  • (2) M12 Flat Washer
  • (2) M12 Lock Washer
  • (28) 1/4-20X3/4 SS flat head cap screw
  • (28) 1/4-20 nylon insert lock nut
  • (28) 1/4 flat washer

Tools Needed:

  • Mechanic’s tool set with a standard assortment wrenches and sockets
  • pry bar
  • 1/4” & 29/64” drill bits and drill motor
  • 1/2-20 threading tap (included with purchase) & tap handle (not included)
  • Anti-sieze compound
  • Pneumatic or electric cut-off wheel & grinder  (My Jeep didn’t need this)
  • Fine-tip felt pen, center punch or marking tool (I used a white pencil)
  • A friend to lend a helping hand (I installed this by myself and use a bucket instead—which sounds kind of sad)



1. Let’s start on the driver’s side. Since my Jeep is a manual I don’t have a transmission cross member. If I did I’d need to momentary unbolt the driver’s side. However the bolt holes are still present on my Jeep.

2. Slide the Rocker Knocker into place. I used a bucket to hold up one end and worked on the other. If I had an automatic I’d be sliding it in-between the cross member and frame.

3. Use the supplied M12-1.5 X 40MM Hex Head Cap Screw with lock washer and flat washer to secure the Rocker Knocker to the frame rail. The rearward two outriggers should be snug to the side of the frame rail as you tighten this bolt.

4. Mark the  centers of the bolt holes for the two rearward cross-members. Be sure to hold the Rocker Knocker tight against the bottom and sides of the frame rail.

5. Remove the Rocker Knocker and drill the two marked holes to a finish size of 29/64”. Start with a small pilot hole of 3/16” and step up the hole size until you’re almost to the finish size. Be sure to hold the drill very straight and  steady on the last pass.

6. Use the supplied 1/2-20 tap to thread both new holes. I didn’t feel comfortable using my drill so I did this my hand, which sucked. The bottom of the frame was surprisingly thick so it took forever



7. Re-install the Rocker Knocker. Start with the same front bolt as before. For the center outrigger, use the 3/16” steel spacer between the mounting flange and the frame rail. Secure it with a 1/2-20 X 1 Gr8 Hex Head Cap Screws and 1/2” Flat Washer. For the rear outrigger, use a 1/2-20 X 1 Gr8 Hex Head Cap Screws and 1/2” Flat Washers (this time without the spacer).


8. Each outrigger is positioned against an adjacent body mount bracket. There is an existing 3/8” hole in the side of the PSC outrigger. Using this hole as a guide and drill a 3/8” hole through the body mount bracket.



9. Bolt the outrigger with 3/8” hardware to the factory body mount bracket through the newly drilled holes. Use the 3/8-16 X 1-1/2 Gr. 8 Hex Head Cap  Screws, Flat Washers and Lock Nuts at the two rearward outrigger, and use the 3/8-16 X 1  Gr. 8 Hex Head Cap Screw, Flat Washers and  Lock Nut at the forward outrigger.


10. Now on to the passenger side and repeat the Rocker Knocker installation process. However, it isn’t necessary to drill and tap the frame. You will re-use the gas tank skid plate bolts for the two rearward outriggers. Remove the two rearward bolts on the gas tank skid. Use a pry bar to separate the gas tank skid from the frame slightly so that the Rocker Knocker mounting flange can slip between the skid plate and the frame rail. I used my bucket trick again.

11. PSC recommends pre-installing the parts, removing everything, then paint or powder coat. I didn’t do that and got lucky. I didn’t need to tweak, trim or cut anything on the part. If I followed their advice I’d be removing everything sending it off to powder coat in this step. Instead, I’m removing it and moving on to the next step :)

12. Install the removable skid plates to the Rocker Knockers using the supplied 1/4-20 X 3/4 SS Flat Head Cap Screws, Flat Washers and Lock Nuts.


13. Perform the final installation of the Rocker Knockers onto the Jeep with the same hardware and procedures above.


PDF Installation instructions

Overall Impressions

I love the look, it really bothered me seeing the naked pinch seam. The Rocker Knockers hug the tub more than I expected and sit lower than I expected. I’d say the most popular version of this product is the body mounted variety, based on my non-scientific survey of Jeep forums. I’ve noticed some of my passengers try to use it as a step to enter the Jeep. It isn’t designed or intended as a step. I’ll have it off-road soon enough and put them to the test. I’ll let you know how they do.

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