A new component recently announced by Rally Design’s Blackline brand is this new Ford Sierra-inspired differential assembly. Back in the day, the Sierra’s diff underpinned so many kit and specialist cars.
Nowadays, though, they are hard to find and, if you do manage to source one, it will almost definitely require a full rebuild. They tend to be pricey because, in a supply and demand world, prices inevitably increase when availability is limited.
The Blackline unit is all-new and Rally Design has tooled and manufactured the diff cases and internals.
The casing now accepts the Blackline HLF014 helical limited slip differential unit without any machining work. Incidentally, the HLF014 is also available with a 23-degree helix angle, which is better suited to lightweight vehicles, thus reducing understeer. Perfect for kitcar use.
Rally Design can also supply service packs of hardware – bearings and seals, which will also fit the original Ford Sierra assembly. In addition, various Sierra 7in crown wheel and pinion ratios are available to suit all kitcar applications and these come in the following ratios: 3.14, 3.38, 3.62, 3.92, 4.11, 4.44 and 4.71.
The assembly is supplied in CKD (completely knocked-down) format for home or professional build-up, which allows for personal selection of diff ratios. In case you aren’t able to assemble the unit, Rally Design can steer you towards a recommended axle assembler.
The complete assembly, including helical LSD but without crown wheel and pinion, costs £1182 inc VAT. CWP in 3.14, 3.38 and 3.92 cost £418.80 inc VAT, with 4.11, 4.44 and 4.72 cost £454.80 inc VAT.
More information from www/rallydsign.co.uk or call 01227 792 792 ENDS.