Remember what wears a thrust washer, it's side thrust. Where's side thrust
come from? Pressing on the clutch. When does it get bad? When you sit at the
traffic light with your foot on the clutch pedal.
So, if you avoid the above, thrust washer wear isn't going to be severe. And
to preclude long term problems, if you've got a 1500, you should replace your
bearings and the thrust washers about every 30,000 miles anyhow (it's a simple
job).
Now add in that every hole you make in the oil galley is yet another leak that
will reduce oil flow to other critical areas, like rod bearings and such. When
the clearances are sloppy, the leak takes even more of the oil flow and
pressure. The thrust washer area is not a tight clearance area! Not when you
compare it to the bearing clearances of the bottom end and such.
To my mind, the drilling of the thrust washers for oil flow is of questionable
benefit. Especially with a lack of size specification from the person
advocating it. The size of the hole would be a critical factor in the life of
the rest of the engine. You've also got a likelyhood of having the oil
pressure push the thrust washer away from the block, and grind it dry against
the crankshaft, while lubricating hapily between the block and thrustwasher
(which isn't a good thing).
The shops caution about drilling both sides if your going to do this is
plausable. If the clearances are tight on the thrust washer, the oil pressure
on the rear certainly would push the crankshaft rearwards, which would/could
cause the crankshaft to ride against the front thrust washer, wearing it down.
But again, even with the block and washers drilled on both sides of the
webbing, you could still have the oil pressure on the wrong sides of the thrust
washers, grinding them against the crankshaft.
Don't ride your clutch, and do frequent oil changes with a good quality oil,
and you will probably not have serious thrust washer problems. If it's a 1500,
replace all the bearings about every 30,000 miles and you won't have problems.
>>> "Fred Griffiths" <griffco@cadvision.com> 02/26/02 06:58PM >>>
Well, I found the article on drilling an oil hole in the block for the rear
thrust washer. Ted Schumaker had written it in the Spit & GT6 magazine.
So I contacted Ted and asked him what size hole. He replied - let the machine
shop decide what size!
So I asked my machine shop guy today and he said - he doesn't recommend doing
this because:
Ford tried it one time, found that the increased oil pressure on the rear
thrust washer caused premature failure of the front washer.
Now I'm really stymied - to drill or not to drill, that is the question. And
if I drill, what size is good?
I am of the opinion that thrust washers fail too early due to lack of lube -
they rely soley on spash oiling, but how to improve that lube?
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