Marzocchi 350 CR Service Guide

Tools & vital fluids required

  • Allen Key Set
  • Flat Head Screwdriver
  • Circlip Pliers
  • 27mm Socket Set
  • 7.5wt Suspension Oil
  • Suspension Specific Grease
  • Isopropynol
  • Lint Free Rags

Thoroughly clean and depressurise the the airspring.

Make a note of how many clicks from open the compression adjustment dial is set to, then remove the adjustment dial

Repeat this with the rebound adjustment dial, it will be stiff so apply gentle even pressure when prising off.

Remove footnut bolts from the bottom of each leg.

over an oil pan, slide the lowers slightly off of the CSU and allow the old oil into pan and remove lowers. Then slide the lowers fully off of the CSU.

Now it is time to remove the airspring

Remove circlip from the bottom of the airspring stanchion

Remove airspring top nut with socket wrench

Remove air tube from the stanchion/CSU

Remove damper top nut with socket wrench

Remove damper from the stanchion/CSU

Deep clean the CSU and lowers with isopropanol

Inspect seals for cracks and damage

Remove and replace seals if necessary

Disassemble and drain damper

First pull the rebound shaft from the damper tube, drain the oil into oil pan

Remove low speed adjustment unit

Deep clean all components

Inspect components and seals, ensure bleedport is clear.

Before reassembling the damper, move the seal head on the rebound shaft to the bottom of the shaft.

Ensure the rebound adjustment is set to fully open.

To refill and bleed the damper, begin by filling the rebound shaft with 7.5wt suspension oil and set aside.

Insert the low speed unit into the damper shaft, invert and fill with oil, ensure all air bubbles have risen to the surface.

Over an oil pan quickly invert and insert the rebound shaft into the damper unit. Some oil will over spill.

The damper is now filled and ready to be re installed, the damper bleeds air and draws oil in the bottom of the rebound shaft when in use. This ensures the damper is fully bled and has the correct oil volume at all times.

Now move onto the airspring, the airspring uses a coil as the negative spring. Coat the coil spring in a healthy amount of suspension specific grease.

Ensure there is an thin amount of grease covering the piston head seals.

Then apply a thing coat of grease to the outside of air tube itself.

Reinsert the air tube into the CSU, tighten the top cap down to the correct torque.

Invert the CSU and pour in 5ml of 7.5wt oil.

With the CSU still inverted, press in the airshaft into the air tube. Re-fit the circlip.

Now move onto the lowers. Apply a full covering of suspension grease to the inside of the dust seals and the inner oil seal.

The last step is full re-assembly, clamp the CSU into a work stand, then work the stanchions through the dust seals. Be careful not to damage the seals of the garter springs.

It can sometimes be easier to work one side into place then the other, regardless be gentle and dont force or apply undue pressure to the seals.

Next take the damper, slide it into the fork, then tork the top cap down to the correct torque.

Re-fit the compression adjustment dial, make sure you dont loose the detent ball bearing while doing so!

Using a syringe, inject 25ml of 7.5wt suspension oil into the lower of each leg of the fork. This will keep thing moving smoothly and give the damper an oil bath to draw from.

Refit the footnuts on both sides, ensure the correct torque is applied.

Next, refit the rebound dial, make sure you fit it to the fully open position, otherwise you wont be able to fully turn the dial. Turn the rebound dial to what it was set to before servicing.

Now do the same with the compression adjuster, ensuring it is set to the same number of clicks that it was prior to servicing.

Finally, re-presurrise the fork, give the whole fork a good clean to ensure there is no excess grease or oil residue.

Grab a beer, thats your 350 CR serviced and ready to go back in the frame.

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I am an artist living and working in Aberdeen, I ride bikes and like to write about it sometimes.

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