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.
Please see the PS below about a rating/nomination of my answer/me.
---------- FOLLOW-UP ----------
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.
Knowledgeability = 10
Clarity of Response = 10
Politeness = 10
Really knows the answers and explains them very well. Very descriptive.
Get a Free Fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.
I answer questions seven days a week and respond to you in about 30 minutes. "Maxed Out" means I am answering another question, briefly unavailable, or asleep overnight, so try again later.
I have do-it-yourself experience (50+ years) and a library of 100 1982-2012 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.
I was voted "Top Expert" 2010-2015, here at AllExperts, and have answered 20,000+ questions.
Five decades as a 'do-it-yourselfer' on domestic and imported cars.
Organizations Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)
Education/Credentials Advanced degrees in Physics/bruised knuckles
Awards and Honors "Top expert" of 2010, 2011, 2012, 2013, 2014 and 2015 here at Allexperts.
Quickest "average response time" at Allexperts (currently no. 1).