Question QUESTION: Hello, I am in need of the torque specs for the connecting rod bearing caps for a 2002 300m 3.5 h.o. . I have come across a few but they vary from 40 lbs to 55 lbs. I dont know which one would be correct for this motor. Thank you for any info you may have.
ANSWER: Hi Paul,
Both the '98 and the '04 manuals I have show the torque to be 40 foot-pounds + 1/4 turn. The spec in N-m is 54 + 1/4 turn, so that may be why the discrepancy in your recollection.
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QUESTION: Thank you for your knowledge and fast reply. Why is there an added 1/4 turn? Wouldn't this in reality equal to about 45 lbs. and why wouldn't/shouldn't it be listed that way? Sometimes things are just made more complicated than need be. Thank you again, you have been very helpful, Paul.
Answer Hi Paul,
That is an interesting question...and one I don't know the answer too. It is quite common for many other torque specs in the Chrysler engine line. Perhaps it is that 40 is a more precise specification to achieve and that an additional quarter turn adds just the correct additional amount of torque in comparison to say seeking 60 foot pounds in a single 'go' at it. I have to beg ignorance but nonetheless I would do it the way it is stated. Possibly when you reach torque levels above around 40 foot pounds or so a variable amount the frictional issues between the two surfaces which could be related to the presence or absence of trace amounts of grease can result in a false torque measurement. So 40 plus a quarter turn may give the correct torque no matter what the metal surface issues might happen to be. And by the way that extra 1/4 turn should be done with a solid handle not a torque wrench.
Thanks for the rating/nomination...which you may to again if you feel so inclined.
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