Monthly Archives: March 2014

Smoother Mugen shocks (Losi mod)

Hi guys,

The Mugen shocks are great with the standard parts, but you can get them smoother with a simple mod.

Here are the parts that are needed for the mod:

  • TLR5074 – Team Losi Racing Low Friction Shock Shaft O-Rings (8)
  • JQP-R-0010 – JQ Products 3.5x7x1.5mm Shock Bushing (8)
  • 5 x 7 x 0.1mm or 5 x 7 x 0.2mm shims (optional)

What you basically do is change out the Mugen O-rings with the Losi low friction ones and the middle Mugen spacer with the 1.5mm JQ spacer.

This is what it will look from top to bottom:

  • Losi low friction o-ring
  • JQ 1.5mm spacer
  • Losi low friction o-ring
  • Stock Mugen spacer (the flanged one)

The Losi o-rings aren’t always 100% leak free.But it’s easy to solve that. First you could try to submerge the o-rings for a few days (3-5 days) in shock oil so they swell up. If they still leak,  you can fit 1 or more 5 x 7 x 0.1mm shims over the flanged Mugen spacer to squeeze the o-rings a little more.
It’s important that you don’t use any bigger shims, because the o-rings won’t get squeezed if the shim is bigger than the plastic spacer. (thicker shims are allowed, but none that are bigger in diameter)
Now turn the bottom cap down, fill them and enjoy your leak free super smooth Mugen shocks 😉

Here are a few pictures of what you need to get rid of the leaking if it occurs. Try to use as little shims as possible, because more shims add more resistance. Just enough until they stop leaking.


5x7x0.1mm shims


Top view


Side view