M18 Greaseable Shackle Bolt

M18 greaseable shackle bolt is the centre bolt used on rocker roller suspension arms. Worn bolts often cause the entire arm to be replaced.

However, Couplemate now manufactures a replacement bush for rocker roller arms.

How do I measure my shackle bolt?

Measure from the tip of the thread to the underside of the hex head.

18mm Worn Rocker Roller Hangers

There is no fix for worn hangers other than replacement.

The knurl under the head of a greaseable shackle bolt has a particular purpose. The knurl locks into the shackle plate to help prevent the bolt from spinning during spring compressions. Broken welds are a good sign the bolts need replacement.

The knurl is welded onto the shackle plate on the outback trailer springs to stop the bolt from turning. With a rotating bolt in the shackle plate, wear significantly increases.

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How to tighten suspension bolts.

• Tighten 18mm x 100mm greaseable shackle bolt until home.
• Back off 1/4 turn.
• You need a small space between your hanger and the rocker's arm; otherwise, you will develop an annoying squeak.
• This squeak is due to no tolerance between the arm and the hanger leg.

Associated Bolts and Bushes

• M18 Standard Tandem Greaseable Shackle Bolt
• M16 Greaseable Shackle Bolt
• M16 Non-Greaseable Shackle Bolt
• 18mm – 22mm Rocker Roller Bush

Replacement Shackle Bolts, Caravan Trailer Kits