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| | | | Joined: Jul 2014 Posts: 892 'Bolter | | 'Bolter Joined: Jul 2014 Posts: 892 | 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 Gallery1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971. | | | | | Joined: Jul 2014 Posts: 892 'Bolter | | 'Bolter Joined: Jul 2014 Posts: 892 | To clear up any confusion I may have caused.......
The main bearings on 55 2nd TRUCK engines apparently are pinned top and bottom just as the earlier mains were. This engine has the low mount water pump just as 56 to 62 engines so one can be easily fooled by appearances. So I ended up ordering mains for 53 & 54 engine and they have fit just fine.
The top pins make doing an in-frame overhaul a lot more work as you have to pull the timing cover and drop the crank far enough to get the top bearing shells out.
1951 3800 1-ton"Earning its keep from the get-go"In the DITY Gallery1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971. | | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | I see you've got it figured out Tommy. But for anyone else that is facing the same thing, here are a few pictures of the mains out of the block: http://www.pbase.com/dennygraham/image/161809704/large And yes, the brg shell does stand above the cap so that the seam in the shells are not in line with the mating surface of the cap and block. dg
Denny G
Sandwich, IL
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