NORFOLK GARAGE
AS the coronavirus restrictions ease I have been gradually opening the Norfolk Garage up to new work again, starting with vehicles needing urgent attention to keep them on the road. One of my regular customers called me about a Defender 300Tdi which was refusing to engage first or reverse gears. I quoted him for a new gearbox and he arranged for the vehicle to be trailered to the workshop. By the time it arrived it had occurred to me that the gearbox might not be at fault – clutch drag (the clutch not disengaging fully) would give the symptoms my customer had described. This is a fairly common problem on older Land Rovers and usually caused by the clutch fluid level dropping too low and allowing air into the system. This gives a soft clutch pedal with lots of travel. On this Ninety the clutch fluid was up to the maximum mark and the pedal action felt entirely normal (if a little heavy) but it was impossible to engage first gear with the engine running. Engine off, no problem.
It seemed likely that there was some kind of mechanical issue with the clutch itself, so I fairly quickly had the gearbox out and found the cause of the problem. One of the cushioning springs in the centre of the clutch plate had broken up: bits of spring had become jammed in the clutch cover, preventing it from moving as it should. There was a fair amount of engine oil in the bellhousing, so I took the opportunity to change the crankshaft rear oil seal. The clutch fork on most Defenders is a rather feeble pressed steel affair and notorious for having the pivot ball punch through the cup if it is not greased adequately. The fork on this vehicle was in perfect shape so I welded a piece of steel bar across the back of the cup to strengthen it. If the fork needs changing you can buy a 'heavy duty' replacement with the strengthener already in place.
With everything back together I took the vehicle for a road test and was amazed at how much lighter the clutch pedal felt. It is quite common for clutches to become heavier as the friction material wears. I fitted a new clutch to my little Peugeot 106 a few months ago and immediately realised why it had been eating clutch cables. Spending most of my time around old Land Rovers I had not realised just how outrageously heavy the clutch action on the Puglet had become.
With the Defender back earning its keep I turned my attention to finishing off the 1964 Series IIA which I wrote about last month. Readers may recall that I had built up a 2.5-litre petrol engine for it using a 12J diesel block and crankshaft. It ran very nicely once I had sorted out some ignition system issues, but after returning to the workshop from its first road test I noticed that it was smoking quite badly. There was a haze of blue smoke from the exhaust at idle, and a big puff of smoke when the throttle was opened. Clearly something was amiss and I had an idea what that might be.
On the 2.25 and 2.5 petrol engines each little end is lubricated via a small spray jet in the side of the connecting rod, fed with oil through holes in the big end bearing shells. The 2.5 diesel uses spray jets bolted to the block, lubricating not only the little ends but the cylinder bores as well. Bore lubrication on the petrol engines has always seemed a bit marginal to me – it is very common on removing the cylinder head to find a sharp step in the bore marking the upper end of the top piston ring’s travel. So I decided when putting this engine together that I would retain the diesel-type spray jets. This now seemed to be the most likely cause of the oil smoke.
The jets are held in place with banjo bolts which turned out to have a standard M8 x 1.25 thread, so I blanked them off with short Allen bolts sealed with copper washers. I had fitted 2.5 diesel-type big end bearings which needed to be changed for ones with oil passages in them. This can be done with the engine in the vehicle although it all gets a bit fiddly when you are trying to seat the new shell in the conrod. The crankshaft journal gets in the way and there is not a huge amount of space to get your fingers behind it and manipulate the shell into place. I got there in the end, refitted the sump, filled it with oil and fired it up. No smoke. I took the beast out for a test drive, got the engine nice and hot and it came back still smoke-free.
When you are mixing and matching parts from different vehicles there is always the risk that something like this will happen. At least I won’t make the same mistake again, and I doubt this will be the last 2.5 petrol engine I build up.