Changing Front Shock Absorbers and Springs

 

Shock absorbers and springs can be obtained from:

 

Ashley Banks Ltd, 5 King Street Industrial Estate, LANGTOFT, PE6 9NF, Telephone 01778 560651, Fax 01778 560721

 

 

This guide has been produced using the very considerable skill and experience of Colin Springall and is based on work carried out on RM471 on 10th April 2005. It took about  two hours to replace each shock absorber

 

Routemasters are big heavy vehicles and great care needs to be taken with the health and safety precautions necessary when carrying out maintenance of the suspension.

 

  1. Choose a safe location with an inspection pit and adequate lighting. Apply the handbrake, chock the wheels and jack up the front of the bus.

 

 

  1. Position an adequate body support stand in the pin located under the body behind the front wheel arch

 

  1. Continue to jack up the front wheel until it can be removed

 

  1. Remove the front wheel

 

  1. Find the two bolts that secure the shock absorber to the top of the suspension unit and remove them. You may have to gently ease the brake pipe away from above the bolt to get a good purchase on the head of the bolt.

 

 

  1. Locate the eight nuts on the lower base plate of the suspension unit. Spray them with WD40.

 

  1. Loosen the nuts and remove six of them completely.

 

  1. Use the jack to keep the base plate in place and remove the last two nuts

 

  1. Carefully lower the jack and the base plate, spring and shock absorber can be removed

 

  1. Undo the nut securing the shock absorber to plate at the top of the spring

 

  1. Remove rubber bushes and top plate

 

  1. Remove the Spring

 

  1. Place the base plate and shock absorber in a vice and undo the four bolts securing the shock absorber to the base plate

 

  1. Carefully clean the top and base plates. Check for cracks around the central area.

 

  1. Secure the new shock absorber to the base plate. Don’t over tighten as you may break the securing caps.

 

  1. Carefully wire the nuts.

 

  1. Place one of the rubber bushes on the top of the shock absorber and carefully locate the spring

 

 

  1. Place the top plate in position, then the other rubber bush and secure with the large washer and nut at the top.

 

  1. ..and tighten.

 

  1. Using the jack, carefully position the shock absorber and spring in place. Rotate until the holes in the top plate line up with the holes in the top of the upper part of the suspension. Insert two of the LONG bolts from the base plate temporarily to hold the shock absorber and spring in place. Do not tighten fully.

 

  1. Reversing step 7 above secure the base plate with the remaining six long bolts, then remove the jack and retrieve the two long bolts temporarily securing the top plate and transfer them to the base plate. Place the two short bolts in the top of the unit and check that all the bolts are tight.

 

  1. Replace the wheel, jack the bus up and remove the body support stand.

 

  1. Repeat steps 1 to 22 on the other side of the bus.

 

The old shock absorbers on RM 471 were completely worn out and the offside spring turned out to be broken. Following the replacement of the shock absorbers and spring the vehicle felt completely different. The ride was very much smoother and the nine big bounces after going over a raised zebra crossing were reduced to one. The steering was lighter but more positive with less play. At speeds of over 35 mph there was a lot of vibration and now there is none. Anybody experiencing these sorts of problems with their bus should seriously consider replacing the front shock absorbers.

 

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