Hi bolters,

I set out to replace the clutch on my 51 3800 and it was oil soaked. So, now I'm into the the rear main seal question and fortunately I have a NAPA rubber oil seal. It's clear that the old one has a lip that is worn compared to the new one so I'm going with the rubber.

Now as long as I'm in there I'm checking the clearance on the mains and I find that the rear cap is doweled as I expected but I find that #3 is not. No tangs either. This bearing is rotated so that the shell stands proud of the block maybe 1/16th and shows some wear. What holds it in place? are the dowels in the block? If so how did it rotate?

Believe it or not, I completely rebuilt this engine frame out in 1975 and remember tapping in a rope seal (which has since been replaced) with a hammer handle but don't remember correctly about the main dowels. I had thought that all the main caps were doweled. The motor has ~180,000 road miles on it and there's no indication that it needs a rebuild but I thought I might replace the mains and rods for good measure. If the block is doweled it's a much bigger deal to replace the mains, so I might skip it but now I'm concerned about this #3 main that seems to have moved.

Any thought about this?

1951 3800 1-ton
"Earning its keep from the get-go"
In the DITY Gallery
1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.