Servicing CV Joints - Formula Ford Zetec

Servicing CV Joints
General
The drive shaft constant velocity joints transmit the engines power from the gearbox drive flange to the drive shafts
and from the drive shafts to the rear wheels via the rear upright drive cup. There are a number of different types of
CV joints used on Formula Ford Zetec's, some have three bearings, some have four. Keeping the joints maintained
is important and they should be dismantled, cleaned, inspected and greased at least once per year.
Having the joints packed with the correct grease will reduce friction, reduce wear and helps to minimise water
ingress. Neglected CV joints are often the root cause of a snapped drive shaft.
Servicing the CV Joints
Start by examining the rubber covers or boots, look for splits or cuts and signs of perishing and cracking. The boots
should be removed and pulled back. There are many different designs of boot, on this Van Diemen the inboard
gearbox drive flanges boots were bolted and at the outboard end they just slip over the triangular drive cups.
The drive shaft will not be fixed to the car at either end, the bearings which are held onto the shaft with a circlip fit
between the cups mounted to the gearbox flange and upright. To remove the drive shaft you will need to
disconnect the rear upright from the track rod and upper or lower wishbone. This will create enough movement to
remove the shaft complete with bearings.

Inspection and Cleaning
With the drive shafts removed all the parts can be cleaned and inspected. Check that all of the spherical bearings
turn freely and smoothly and that the assemblies move freely on the splined ends of the drive shafts. Clean out all
of the old grease from the inside of drive cups. Check for damage such as cracks or corrosion. At the centre of the
gearbox drive flange of this Van Diemen there is a spring and abutment. The abutment and spring arrangement
keeps the drive shaft pressed into the upright drive cup and is what permits the shaft its lateral movement.
Greasing and Rebuilding
Once all of the parts have been cleaned and inspected they can be greased and replaced. It is essential that you
use a specific CV joint grease, such as a good quality Lithium-Moly based grease, which is normally darker in
colour due to the Molybdenum content.
Smear a generous amount or grease onto the bearings and splines and pack the inside of the drive cups. Replace
the spring and abutment and carefully place the inboard end of the drive shaft into the gearbox cup. You will need
to support the drive shaft as the upright is moved back into position and the triangular drive cup is engaged.
Replace the suspension bolts and tighten correctly.
Technical articles should be taken as advice only, if in any doubt consult a qualified mechanic or the parts supplier/manufacture.
www.formulafordzetec.co.uk
Author: James Chapman