Twisted cage
AN old long wheelbase Series III was dropped off at the workshop last week. It came in on a trailer, the owner reported a loud bang from the gearbox area, followed by the gearbox jamming in third and requiring both hands on the gear lever to disengage it.
The vehicle is a fairly regular visitor and quite an unusual beast in that it started life as a One Ton pick up. This was a rare and short-lived heavy-duty version of the 109in with the six-cylinder petrol engine, special low ratio transfer box, stronger axles and springs on extended spring hangers, and big 9x16 tyres. Utility companies bought a few, but for most users the extra quarter tonne of load capacity was not enough to offset the low top speed and outrageous thirst for petrol.
This particular One Ton lost most of its distinguishing features long ago and, like many old Series Land Rovers, could best be described as a bit of a mongrel. It now has a 2.5-litre non-turbo diesel engine which previously powered a military One Ten, coupled to a Series IIA gearbox. I was curious to see what had caused the gearbox to fail as the symptoms were not familiar to me. On removing the bellhousing I found a couple of broken bits of steel lying in the bottom. These turned out to be the remains of the thrust washer which sits inside third gear and is retained by a snap ring. The washer had fractured, possibly due to sheer old age.
Once I had removed the selector forks and extracted the third/fourth synchromesh hub all became clear. One of the bits of thrust washer had become jammed in the hub in such a way that the entire cage had twisted – not something I have seen before. Who says 2.5 non-turbo diesels are gutless? The rest of the internals turned out to be in good shape, but the steel carrier for the rear main bearing had spun in the casing and worn a fairly deep groove in it. Luckily most Series IIA (and early Series III) gearbox casings are the same and I have a few spares. I have noted the damage on the old one and stashed it away. Not long ago it would have gone in the scrap bin, but I suspect that in a few years’ time I will be glad I kept it.