With the T140 I'm rebuilding I noticed that the conrods would drag on the crankshaft and hang up when. Case was still together and the jugs removed. Rods at top of travel, they would not move freely, kind of sticky.
When I cracked the case open I found a bunch of crud in the bottom. When I removed the plug to the sludge tube, the tube was full of crud and into the rod journals.
So yes definitely a clogged sludge tube will restrict oil flow to the rod bearings.
By luck, the journals polished up very nice with 2000 grit paper and oil with no scoring of the surface.
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