How difficult can it be?
Dave makes a special propshaft for his Shadow
With the new gearbox and suspension in place it was time to refit the back axle and measure the distance between the two so that I could make a propshaft.
In order to access the propshaft, first of all you need to remove the rear differential, carrier and halfshafts. Luckily for me these had already been removed prior to renovating the body so I was able to simply slide the old propshaft down the transmission tunnel and, with a trolley jack and two bolts, temporarily lift the differential and carrier into place to measure the length needed for the new propshaft. With my trusty vernier and –allowing for expansion and some play – I measured the gap at 81mm.
With the prop on the bench I set about cutting it up to remove the pieces that I would re-use and to ascertain the size and wall thickness of tube that I would need to order. I carefully removed the yokes from each end, bought tubing and set to work. First of all, it’s vital that at least one end of the tube has been cut square, preferably with a lathe, in order that the end of the tube is exactly 90 degrees to the sides. If not you could end up with a rhombus rather than a square. I then hammered one of the yokes into this end and measured it several times before tack welding it into place. The other end of the tube could be rough cut with an angle cutter as it’s the yoke that has to be aligned accurately but once tacked into place and double checked for accuracy both yokes could be welded into place. With new UJS fitted it was off to H J Chard Engineering to get my propshaft balanced.
Balancing act
Once spun up on the balancing machine, the balance weights needed were actually smaller than the ones fitted to the original Rollsroyce prop shaft ! Slid up and bolted onto the output shaft of the gearbox that is on a sliding yoke to allow for expansion and play, the new shaft looked to be the correct length and with the differential carrier bolted firmly back into the car the propshaft was a perfect fit with the designed gap of 3mm between the shaft and the differential to allow for expansion and play. A job well done.