Why fit solid CV driveshafts on your classic Lotus Elan?

Ever since the Lotus élan S1 was released to the public in the early 1960s it soon became apparent that the driveline would not withstand vigorous driving habits, many stories abound of the intrepid élan driver stranded miles from the workshop with a broken rubber. donut or metalastic joint, and changing a donut on the side of the road is not the way to spend time with his friend in the lotus elan… no sir.

There have been a number of different transmission line replacement alternatives to the donut, some have offered a half and half deal, where a universal joint was used in conjunction with a donut, the thinking behind this idea is that the donut provided an effect of damping within the driveline, although the idea is good in theory, the system was still prone to failure.

Another idea put forward was to use two universal joints and a slip spline yoke to replace the rubber donuts on each half shaft, at first this seemed like an ideal solution but unfortunately due to their design the slip splines will lock up under certain conditions. conditions, and universal joints also produce variations in rotational speeds, i.e. they speed up and slow down momentarily with each rotation, the phenomenon is known as “cyclic speed variations” and is unique to universal joints when they operate at more than a few few degrees from the centerline to which they would of course be subject when used on the rear driveline of a lotus elan, movement in the rear suspension travel will produce various degrees of movement in both bump and rebound. The moments of cyclic variation occur only for milliseconds, but the phenomena can be unsatisfactory in the transmission line of a lotus elan.

The constant velocity joint is designed so that when the drive angle varies, the balls are always positioned mid-point within the joint. This eliminates the aforementioned cyclic variations in speed that a universal joint produces when operating a few degrees off center, if the operating angle is extended too far the UJs will tend to lock up.

A rubber boot, which keeps grease in and contaminants out, protects the constant velocity (CV) joints. CV joints require only periodic maintenance or greasing and are designed to last 100,000 miles (160,000 km) or more.

The initial cost of converting a Lotus elan to a CV drive system is high, but the initial cost is fully offset by long-term maintenance and donut replacement.

The elantrikbits CV Driveshaft System produces 100% reliability, because the system is well designed and known to provide many years of trouble-free service.

Another important factor to consider when fitting a solid CV driveshaft to a lotus élan is ease of installation, a well designed system will only require the removal of the old intermediate driveshafts and rings, the new system is simply offered to the inner and outer drive flanges, normal wrenches and tools is all that is needed to tension the high strength fasteners.

If the driveshaft kit you are considering requires more than just normal shop tools to install and requires removal of your élan’s rear suspension, the total cost of installation will be much higher than the initial purchase cost, because because you will have to pay for the services of a professional installation mechanic.