bolt grade

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  • E30_fiend
    R3V OG
    • Apr 2006
    • 7348

    #1

    bolt grade

    I need to replace a few bolts from the diff where it mounts to the subframe. The bolts I pulled off are grade 8 M12x1.5 bolts. I went to my local bolt supplier because my metric bin didnt have the 1.5 thread pitch. The only bolts they had in the size I needed ad thread pitch I needed were grade 5 bolts.

    No my question is this. Was BMW being anal by putting grade 8 bolts in there or would a grade 5 bolt wor just fine? This is one of those things that you really dont want to take a chance on you know?


    Can anyone help me out?








    Taylor
    Need a performance chip for you BMW? Shoot me a PM and I'll get you taken care of!!
    Taylor- Follow me on Instagram @e30_fiend


  • whiltebeitel
    R3VLimited
    • Apr 2007
    • 2098

    #2
    You could use the grade 5 if you are nice to the car, but i'd only suggst having them in long enough to find the grade 8's.


    McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.
    '89 325i track sloot
    '01 530i daily

    -Enginerd

    Comment

    • Stevie30
      E30 Mastermind
      • Apr 2007
      • 1534

      #3
      Go with the grade 8. Don't shortcut safety.

      1991 325ic and 1991 318is

      Comment

      • E30_fiend
        R3V OG
        • Apr 2006
        • 7348

        #4
        I understand the safety thing but what i meant was BMW just being overly safe? The grade 5 bolts are still really strong but just not the strenght of grade 8
        Need a performance chip for you BMW? Shoot me a PM and I'll get you taken care of!!
        Taylor- Follow me on Instagram @e30_fiend


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        • rThor432
          No R3VLimiter
          • Feb 2007
          • 3907

          #5
          Hard to say about the grade. I personally would go with the grade 8 bolts just because of all of the stress those bolts see, as you know. I've seen those bolts back out on track cars that are driven on the street. The vibration gets to them. If they see enough stress to break them loose when properly torqued, I might worry about what would happen with a grade 5 bolt.

          Hope that makes sense and is relevent enough. Just my thoughts on the subject.

          Comment

          • E30_fiend
            R3V OG
            • Apr 2006
            • 7348

            #6
            Originally posted by rThor432
            Hope that makes sense and is relevent enough. Just my thoughts on the subject.
            thank you
            Need a performance chip for you BMW? Shoot me a PM and I'll get you taken care of!!
            Taylor- Follow me on Instagram @e30_fiend


            Comment

            • StereoInstaller1
              GAS
              • Jul 2004
              • 22679

              #7
              I would get out the phone book and find some Grade 8.

              GL!
              Luke

              Closing SOON!
              "LAST CHANCE FOR G.A.S." DEAL IS ON NOW

              Luke AT germanaudiospecialties DOT com or text 425-761-6450, or for quickest answers, call me at the shop 360-669-0398

              Thanks for 10 years of fun!

              Comment

              • JGood
                R3V OG
                • Jan 2004
                • 7959

                #8
                Grade 8. Unless you want to replace your axles, wheel bearings, diff bearings, driveshaft, etc.. when your diff falls down on the highway.
                85 325e m60b44 6 speed / 89 535i
                e30 restoration and V8 swap
                24 Hours of Lemons e30 build

                Comment

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