Strengthen your Triumph’s rear end

Nigel upgrades his TR6’S rear hubs and studs

Why do it?

The big Triumphs – big saloons, Stags and TR4A to TR6 – share an independent rear suspension design that can have a couple of problems. In most respects it’s a good setup, but there’s an inherent weakness in how the hubs attach to the trailing suspension arms. Six 5/16in UNF studs hold the hubs onto the alloy suspension arms. A small, fine thread in alloy can easily strip, with potentially disastrous consequences. The second problem is age related; dismantling hubs for bearing replacement requires huge pressure, which can distort the flanges. Axle shafts can also fracture from fatigue.

What’s being done?

Classic Driving Development have engineered solutions for both problems. They offer brand new hubs with stronger shafts and larger bearings in an alloy housing. These are available to fit to the existing UJ driveshafts, or in a kit to convert to Cv-jointed driveshafts.

The same company supplies upgraded stepped studs, with a stronger 3/8in UNC thread into the suspension arm, and the original smaller thread on the outer ends. In these pages I’m fitting a pair of UJ hubs and stepped studs to my TR6.

How I did it

Fitting the studs required accurate drilling and re-tapping of the suspension arm threads. If you’re not confident in doing this yourself, it’s worth seeking expert help as it’s critical that these are perfect. After removing the old hubs and driveshafts then splitting the outer universal joints, the new hubs fit easily to the existing driveshafts. It’s critical to retighten everything to the specified torque and replace Nyloc fasteners, too.

Drilling and cutting new threads to secure the hubs is safety critical. To ensure accuracy, use the kit of jigs and taps by Classic Driving Development.