Citroën Traction Avant

The classic Citroën Traction Avant was manufactured 1934-1957.

This is my beautiful, almost original 1936 model 7C
- It has front wheel drive, 
- torsion bar suspension, 
- overhead valve engine,
- all steel welded monocoque body, 
- hydraulic brakes.
Click on the following links to see more: -
Pre/Post photos 

Other photos 

Movie (with some covered bridges). Videography - Donal McNally.

A Traction is not a Traction without its drive shafts

The Citroen 7CV that wowed the crowds when launched in Paris in 1934 soon became universally known as 'la Traction',not 'la Monocoque', or 'Barres de torsion' or one of its many other revolutionary features? The front wheel drive was the feature that really captured everyone's imagination. It also permitted the flat interior floor (no transmission tunnel) and together with the welded body, the low ground profile.

However, these are a weak link in the drive train. Those six universal joints, with their four needle roller bearings each, do wear out. The needles wear grooves in what should be a rolling surface, and start to lock up. The cups then start to turn on their housings, and everything becomes progressively loose.

Grooves worn into the universal joint (Spicer) needle roller bearing surfaces.

Yes, you can replace the original drive shafts with the modern constant-velocity version, but then it's not really a genuine Traction. So, make do and mend. The inner joints, at the gearbox end, are relatively easy to work on, except you have to lift the engine/transmission to get enough clearance to get them out. (This after loosening the suspension adjusters and jacking up the wheels, for more lateral clearance.) But working on the outer joints (Cardans) is challenging. The design is very cunning - between the two Spicers there is a ball joint that maintains a center of rotation mid-way between these two joints. This serves to equalize the angular movement between the two Spicers.

The complete outer Constant Velocity joint.	Parts of the outer constant velocity joint. The holes in the Spicers are for the ball joint spigots. The protective housing for the ball joint is not shown.

Each half of this ball joint rides on a spindle (spigot) inserted into the outer stub axle and drive shaft respectively, passing through a hole in the Spicer's cross piece. So, you can't get the cross piece out without first pulling the spigot out of its housing. It's a seriously interference fit - you need a special tool that is built with indestructible proportions. Then, after assembling the required parts you have to push those ball joint spigots all the way back into their housings in the axle and drive shaft. I used my home-made tool to press the spigots into place.

Clamp made to press ball joint mounting spigots into the drive shaft and axle.

You can buy replacements for the Spicers, but I improvised. I ground down each of the four limbs of one of my knackered inner Spicer cross pieces, and made up for their undersize by fabricating oversize needle rollers from ground tool steel rod ($2.50 from McMaster-Carr), cut to length and then hardened by heating and quenching. This seems to be working, but time will tell.