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I'm replacing the exhaust manifold gasket on a Nissan Altima and cannot figure out how to interpret the service manual diagram for the torque specs. From Google research, the bolt (the green arrow is pointing to) requires 29-32 lbs. but I'd like to understand this diagram before proceeding.

I could not find any legend or key anywhere in this manual or online.

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2 Answers 2

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Couple of notes on how to read this manual.

A White wrench in a black square has the units N-m (kg-m, ft-lb)

A Black wrench in a white square has the units N-m (kg-m, in-lb)

So - the bolt very top left in your diagram should be tightened to 51 inch pounds (i.e, 4.25 ft-lbs - not very tight!). The nut on the left immediately below that bolt should be tightened to 11 ft-lbs - over twice as tight, but if you just look at the numbers, 11 versus 51, you'd think that the top left bolt was put on tighter.

Here are some other symbols you'll see;

enter image description here

The item in green is a stud. The stud goes into the engine block at a torque of 11 ft-lbs, and then the nut attaching the manifold to the stud is tightened to 31 ft-lbs.

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  • 1
    Great info! Especially the first part about black/white boxes ... did not know this! :o)
    – Pᴀᴜʟsᴛᴇʀ2 ♦
    Sep 10, 2019 at 21:07
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    Me, knowing something that @Paulster2 didn't! That's just made my day! :D
    – PeteCon
    Sep 10, 2019 at 21:08
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    There are PLENTY of things I don't know, but yes, bask in your glory, Pete! :o)
    – Pᴀᴜʟsᴛᴇʀ2 ♦
    Sep 10, 2019 at 21:09
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    Outstanding answer. Just last week I spent an hour trying to figure out the units for the torque values in a Nissan manual. I felt like I was being tortured by a sadistic Nissan engineer, snickering in front of his CAD monitor. Thanks!
    – John Meyers
    Sep 11, 2019 at 0:36
  • took me 30 minutes to find this info but thrilled to have done so,thank you!
    – joepolok
    Mar 1, 2020 at 18:44
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Judging from the ratios between the numbers, they are different units:

Newton.meters (kilogram.meters, pound.feet)

1 Kg.m = 9.8 N.m and 1 lb.ft = 1.36 N.m

From the diagram, I would think the cylindrical thing is a separate part, which is screwed into the cylinder head with a torque of 14.7 to make sure it is fully inserted into the head, and then the short bolt screws into the end of the cylinder with a torque of 41.7.

There must be some reason this is two separate parts, and not just a long bolt like the one that goes into the bracket labeled "2" with torque 48.0.

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