E21 LSD diff

[jarocho]

Hello, i got an LSD diff on my 76 2002 when I bought it, I wanna rebuild it but, I couldn't find the exact model and year it came from, if any of you can tell me what exactly I got here 

[TobyB]

You want parts for the later E21 diff- getting parts for an '81 will be safe.

 

t

 

[Conserv]

The housing was cast January 28, 1981 ("28  1  81" on underside).  Just under the pinion and ring tooth numbers "11    43", which tells us it's a 3.91 [43/11]), on the left front side of the housing, a month and year date should be stamped.  I clearly see the "3", which would be March, but I don't see a single-digit year underneath the month (I'm expecting 1981, which would be represented simply by a "1").  The stamped date, in contrast to the cast-in casting date, tells when the unit was assembled.  Just as a check that we're in the ballpark, the unit has 6-bolt covers on the output flanges, which indicates a unit manufactured after 1978.

 

Or....you can skip all this fuss and simply ask Toby, whose gut response gets you to the right answer...☺️

 

Below are three photos of the 1978 LSD currently in my '76.  Note the housing was cast April 26, 1978 ("26478" in first photo), and the unit was manufactured in May 1978 ("5" over "8" in second photo).  But, being and early e21 differential, the unit has 4-bolt covers on the output shafts.

 

Regards,

 

Steve

 

EDIT:  In the updated photos in the initial post, I can now see the "1" (i.e., the year stamp, representing 1981) below and slightly right-of-center with respect to the "3" (i.e., the month stamp, representing March.  Thus, the unit was assembled March 1981.

 

Edited June 15, 2017 by Conserv

[AceAndrew]

Yep, order parts for a late E21 LSD and you are set.  Don't forget to check breakaway torque prior to disassembly.  It'll give you a good indicator as to the health of the pumpkin.

[TobyB]

Quote

the unit has 6-bolt covers on the output flanges, which indicates a unit manufactured after 1978.

and sometime after about  the middle of 1979, too...

 

t

 

[jarocho]

On 6/11/2017 at 4:27 PM, Conserv said:

The housing was cast January 28, 1981 ("28  1  81" on underside).  Just under the pinion and ring tooth numbers "11    43", which tells us it's a 3.91 [43/11]), on the left front side of the housing, a month and year date should be stamped.  I clearly see the "3", which would be March, but I don't see a single-digit year underneath the month (I'm expecting 1981, which would be represented simply by a "1").  The stamped date, in contrast to the cast-in casting date, tells when the unit was assembled.  Just as a check that we're in the ballpark, the unit has 6-bolt covers on the output flanges, which indicates a unit manufactured after 1978.

 

Or....you can skip all this fuss and simply ask Toby, whose gut response gets you to the right answer...☺️

 

Below are three photos of the 1978 LSD currently in my '76.  Note the housing was cast April 26, 1978 ("26478" in first photo), and the unit was manufactured in May 1978 ("5" over "8" in second photo).  But, being and early e21 differential, the unit has 4-bolt covers on the output shafts.

 

Regards,

 

Steve

 

 thank you, great info

ill be only doing the seals and bearing, which BTW any recommendations on where to get all of that?

[jarocho]

On 6/11/2017 at 4:27 PM, Conserv said:

The housing was cast January 28, 1981 ("28  1  81" on underside).  Just under the pinion and ring tooth numbers "11    43", which tells us it's a 3.91 [43/11]), on the left front side of the housing, a month and year date should be stamped.  I clearly see the "3", which would be March, but I don't see a single-digit year underneath the month (I'm expecting 1981, which would be represented simply by a "1").  The stamped date, in contrast to the cast-in casting date, tells when the unit was assembled.  Just as a check that we're in the ballpark, the unit has 6-bolt covers on the output flanges, which indicates a unit manufactured after 1978.

 

Or....you can skip all this fuss and simply ask Toby, whose gut response gets you to the right answer...☺️

 

Below are three photos of the 1978 LSD currently in my '76.  Note the housing was cast April 26, 1978 ("26478" in first photo), and the unit was manufactured in May 1978 ("5" over "8" in second photo).  But, being and early e21 differential, the unit has 4-bolt covers on the output shafts.

 

Regards,

 

Steve