In two separate phone conversations this morning, folks have brought up a discussion about did I see this thread topic and asked my opinion. I was going to stay out of it, but since I saw my name mentioned above, I'll get involved with my 2 cents...
So in reality, what is leaking and why? Back in the day, the weak-link IMO would have been a cork gasket however with modern gaskets and sealants, should this really still be a problem?
Take the rear differential for example, if the flanges on the axle housing are trued in a lathe, this really helps cut down on leakage. There are many thread sealants on the market to use on the axle housing to diff housing bolts. Add a
little sealant to the drain plug and leaks in the center should be non-existent. With regard to the torque tube, a small bead of sealer on the flanges that have been true will pay dividends there too. Use a quality gasket on the speedometer cable adapter along with a thin film of sealer on the gasket and the fasteners, and you should be good. If the bell end of the torque tube is deburred and polished on both the outside and inside, this really helps too. Most people do not install the gaskets correctly here either.
Next is the transmission. Sealed bearings have come a long way towards keeping the trans lube in place, and now with O-ringed aftermarket shafts, and/or the Mitchell O-ring kit will help. Using the correct viscosity lube in the transmission along with making sure the vent is not plugged helps the lube inside too. Also, sealant on the retainer gaskets and bolt/drain threads will help.
I think most engine leaks come from junk gaskets and over-tightening fasteners. Proper rear crank journal to bearing clearance, good pan & side-plate gaskets, along with ensuring both the pan & the plate is flat helps keep the oil in and no drips.
So now we have leakless water pumps and leakless gas valves to cure those problem areas, ...along with steering gear boxes that have aftermarket tubes for the bottom, O-rings for the sector shaft, and if someone takes the time to fit the sector housing to the gear box housing, by the time the correctly styled & fitted sector bushings are used, there is no reason why any of these three things should leak.
The only other two things I can think of would be radiators & shocks, and surely those are cured in the aftermarket. So, what else can possibly leak besides vacuum, the roof, and electrical??
I personally see no reason why a 'restored' car should leak fluids. Am I missing something??
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