Jump to content

Speedometer for 3.91 diff

Recommended Posts

16 hours ago, Freude am Fahren said:

Interested. Is there a diff that could potentially go with this?


The 1.393 speedometer was intended for the 1976 49-state ‘02 with a 3.90 factory differential, but is now often used, appropriately, with a 3.91.  Although it had a different ring-pinion gear set than the e21 3.91, the ‘02 3.90 was an attempt to regain some of the acceleration lost to emissions controls. I note that someone wrote “3.90” on the seller’s unit.


During 1976, however, it was discovered that some 1976 speedometers, such as my ‘76’s, dated March 1976 (first photo below), although stamped 1.393, were accidentally equipped with 1.28 gearing by the factory.  Brief blurbs in early Roundels captured this goof (second and third photos below) and its remedy: an overlay for the speedometer’s face with adjusted speeds.















Edited by Conserv
  • Like 2
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Upcoming Events

  • Create New...