I was just thinking last night about former car repair adventures with
my father, and we had at times replaced main bearings with no serious
engine disassembly. This is a lost art, I believe, because so few cars
in later years will allow pan removal without engine removal.
This is not the best fix, however, and will only forestall the eventual
rebuild, but for the adventurous, it's worth a try. And it's cheap.
You would want to know first whether the crank has ever been ground, in
order to know what bearing size to use. But if unknown, you must start
with standard.
The technique uses a dowel in the oil hole of the crank surface,
protruding up just enough so as to catch the edge of the bearing. Going
the appropriate direction, it will rotate the bearing around and out.
Probably want to loosen the other two when doing this, and spark plugs
out, etc.
New bearings install the reverse of disassembly.
Plastigage is then used to determine what you did for clearance. Of
course, I would begin with a plastigage check before doing anything
before you condemn the bearings.
Plastigage will tell you right away if the crank was ground undersize by
some PO.
Also, we used to put steel shims under stock and/or worn bearings to
adjust for the wear. Really cheap.
Paul Asgeirsson wrote:
>Hi John,
>
>In order to ease your pain of replacing the engine bearings, I have but 3
>words. Pull the engine!
>
>Paul A
>
>----- Original Message -----
>From: <john.dagostino@comcast.net>
>To: <spridgets@autox.team.net>
>Sent: Monday, February 05, 2007 6:41 AM
>Subject: bearings
>
>
>
>
>>Hi.
>>Spring will be here soon, so I figured I better look into the low oil
>>
>>
>pressure problem on the Sprite. Yesterday I removed the pan to examine the
>bearings. I found the oil pickup tube was loose where it screwed into the
>block, probably not good. Lots of gook in the pan too, no big pieces
>though...
>
>
>>The center main bearing wasn't too bad, just starting to wear through, the
>>
>>
>journal looks fine too, no scoring.
>
>
>>So, can anyone offer any tips on replacing the bearings in-situ? Can the
>>
>>
>thrust bearings be done also?
>
>
>>I guess they are standard bearings, since there are no markings other than
>>
>>
>AEG 158 on them. It's a 1968(1275).
>
>
>>Thanks,
>>John
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