Announcement

Collapse
No announcement yet.

Diff Ratio question

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Diff Ratio question

    anyone know how i can tell what diff ratio i have.... My car is a 89 325 I i was told it came with lsd Thank you in advance
    sigpic

    #2
    depends if it is an auto or 5-speed.
    http://instagram.com/dslovn.drives

    Comment


      #3
      99% chance its an open differential. If you have a 5 speed, you have a 3.73 open diff. If you have an auto, its a 4.10 open diff. The only way you have an LSD is if the previous owner changed it, unlikely, or the first owner got it from the dealer as an option when it was new







      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


      Comment


        #4
        its not that unlikely, these cars are 20 years old and changing diffs isnt unheard of. who knows the story. theres a little metal tag on the differential with the ratio stamped on it. if it says S3.73 or S4.10, the S means LSD. assuming the diff cover/tag is original to the diff.

        Comment


          #5
          where is the S located on the diff i did a vin look up on bimmer forums amd came up with this
          209 LIMITED SLIP DIFFERENTIAL (25%) <<<??????? what is 25%
          sigpic

          Comment


            #6
            If the diff isn't too rusty, there should be a large S on the bottom to signify LSD. If you don't see that, the ratio tag will be on one of the bolts holding the diff cover on. There will be a S preceding the ratio numbers.

            Another was to tell is to jack one rear wheel off the ground and see if it spins freely. If not, it is a LSD.


            The 25% is the lockup ratio of the diff.
            Byron
            Leichtbau

            Comment


              #7
              the vin look up said lsd so im guessing it is but ill check just in case thank you for advice
              sigpic

              Comment


                #8
                %25 is the lock up ratio (standard % for stock lsd diffs)...
                Mtech1 v8 build thread - https://www.r3vlimited.com/board/sho...d.php?t=413205



                OEM v8 manual chip or dme - https://www.r3vlimited.com/board/sho....php?p=4938827

                Comment


                  #9
                  Originally posted by E30_fiend View Post
                  99% chance its an open differential. If you have a 5 speed, you have a 3.73 open diff. If you have an auto, its a 4.10 open diff. The only way you have an LSD is if the previous owner changed it, unlikely, or the first owner got it from the dealer as an option when it was new


                  Taylor
                  It was an option for the 325i. Standard was open, but you could order one with the LSD. Sounds like that is the case on this car. (But checking the tag is the sure way to know... somebody could have switched in an open diff)
                  1987 E30 325is
                  1999 E46 323i
                  RIP 1994 E32 740iL
                  oo=[][]=oo

                  Comment

                  Working...
                  X