Toyota B Main Bearing Torque Specs

Joined
Jan 5, 2015
Messages
37
Hi guys, I need help. My manual says 145ft lbs. I am trying to achieve it but in the process stretched 4 bolts. Why does it seem so tight? I am using a 50-220 Torque wrench.

I have reused these same bolts twice as this is the second overhaul.

Are my specs right or are the bolts too old?

I can find new bolts 8.8 but they are only rated to 90ft lbs and the bolts at wreckers of an old B motor, im hesitant to buy since it might be old too.

my engine is a B, B stamped on the block.

I'm lost and have tried researching for answers.

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Joined
Jun 26, 2003
Messages
101
 
 
 
There are different main bearing bolts depending upon the year. In the 10yr productiion life of the B engine, there were at least 3 different main bearing bolts used, 12mm, 13mm, and 16mm, each with a different thread pitch. Two of the torque specs are listed above, and another spec from the Aug 1980 B manual is listed at 92-103ft-lbs.
 
Joined
Jan 5, 2015
Messages
37
wow thank you so much, any wonder I screwed up my bolts,

I just bought some bolts from an old B block in a wreckers. These have 19mm heads so I'm guessing its the 16mm.

I dont know how the manual expected these to handle 145ft lbs. From experience 100ft lbs is plenty so I'll use that figure.

Do you think thread locker is a good idea?
 
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