The rear of my Series III is making a grinding noise. It starts after I slow down from 45mph and gets really bad after pressing the clutch at this speed. It started when I switched to two-leaf parabolic springs. I’ve replaced the rear diff, which was apparently off a Series I, with a reconditioned SIII one and although the noise improved slightly, it was still there. The halfshafts and rear prop are good.
I added 3o caster angle wedges to the rear axle, hoping that would clear the noise – but it still remains. The gearbox was recently reconditioned and upgraded to the Ashcroft transfer box. I’m at the end of my tether trying to figure out what the noise could be, as it doesn’t sound healthy. My next plan was to change the rear and front propshafts.
Peter Jenkins, Telford, Shropshire
Grinding noises can often be traced to worn propshaft UJs or output/pinion bearings.
Try driving it in 4WD with the rear propshaft removed and see if the noise disappears. If it does, you’ve narrowed down the problem area.
I assume from the fact that you’ve fitted caster correction wedges that the springs have lifted the car quite a lot. If this is the case, it may be as simple as the angles on the prop UJ being too great. The short-wheelbase rear prop is quite short and does struggle if the vehicle is lifted too much.
This workshop advice appeared in the December 2015 issue of LRO. Back issues are available to download on digital devices here.