Hello all I was wondering if anyone could decode this rearend for me I just pulled it this weekend on the axel tube it says LD1023K I am curious what LD stands for i know its oct 23. Also on the housing i saw M1 D & N the & is some weird flame like symbol and above that is a M in a box. then J208 then 3959038 thanks in advance...

unbelievably frustrating maybe i might find the build sheet on top of the gas tank when i pull that tomorrow? LD never heard of it its picking at my brain

LD - ? Are you positive that it is an 'L'?
I don't see any codes beginning with L
10 - October
23 - 23rd day of the month (Assembly date)
K- McKinnon Industries

The J208 is the casting date - October 20, 1968.
3959038 is the part #

yeah i know its definetly an L ive been staring at it for hours ahhaha

Only LD code I find are these;

LD - 3.23 non-locking (42-13)
10 bolt cover
8-1/2" ring gear
Buick 1974-75
Pontiac 1975 (coil spring)


Source - Hollander Interchange Classic parts indentifier 1960-1989

hmm thats odd its not a 10 bolt im pretty sure its a 12 the two top and bottom bolts are in line with each other the ribbing between the bolts and the cover has that indent in it maybe i can try to take some pics for everyone

Pretty sure? All you need to do is count the bolts and you will know.

Once thing to note, some Olds rears have 12 bolt cover but only 10 bolt ring gear.

If you are sure its a 12 bolt cover etc, then you better double check the stamped code because I can't find any Chevy axles with that code. Ther might be another letter before the LD?

Yeah It has 12 bolts the guy I bought it off of told me it was a 10 bolt but I read an article in a magazine in which it was said that a 12 bolt rearend will not just have 12 bolts on the cover 10 bolt rearends can have 12 bolts but it is the way the bolts are aligned. In the fall 2003 muscle car review "To identify this rearend, look at the retaining bolts at the bottom of the differential cover. If there are two directly opposite each other, you`re looking at a 12 bolt." which is how mine is with the ribbing between the bolts and on the cover so with this information i am sure it is a 12 bolt and the LD is definetly there I am going to borrow a digital camera to take some pictures to show you will that help or is the code still no where to be found

also with the dates 1023 K and the J208 or 9 on the cover thats october 20-23 68 69 am i right?

I just counted the ring and pinion gears and got a 43 to 14 ratio which was also imprinted in the ring gear along with xxxx691 gm (cant remember the rest) so maybe a new rearend code has been found? 69 malibu made in canada i dunno works out to a 3.255 gear ratio non posi thanks for everyones help!!!

http://www.oldsmobility.com/10bolt-tech.htm

Could it be the "O" rear end thats on this site?

No the O rearend on the website has the wrong cover the bolts are lined up like the o type but it has the inverted v cover
"Most Chevy-style 8.2" 10-bolts use the 11" cover with an inverted "V" groove (for internal lubrication) across it's face, just like the 12-bolt version"

"Remove the inspection cover and check the side of the ring gear for two numbers...for example, 43:13. This means that there are 43 teeth on the ring, and 13 teeth on the pinion. 43/13 = 3.31 ratio." that is exactly like my rearend so now im 100% sure about the gears and rearend thanks for that site that has everything i need

whoops got carried away with that site mine has a 43/14 ratio which makes it a 3.07 non posi unit

This is a chevrolet 12 bolt. The one under my 69 Chevelle to be exact. See the upside down V on the cover? The beads between the bolts, are there too.

http://f1.pg.photos.yahoo.com/ph/yenko_chevelle_69/detail?.dir=/6402&.dnm=d036.jpg

Also, you can see the casting date in this picture for my rear end....K138, thats the only place a casting date will show up on a 12 bolt. On the front side pass side axle tube, you will see the stamped numbers telling the gear set, plant, and assymbly date.
"Most Chevy-style 8.2" 10-bolts use the 11" cover with an inverted "V" groove (for internal lubrication) across it's face, just like the 12-bolt version"
I have had 5 or so stock 10 bolts over the past year with the factory covers, and none of them have had the 12 bolt V stamped into the cover.

I show LD was a 3.07 Chevy non posi 12 bolt, but it was one of the Chevrolet rears used in a 70 GTO. The date code should be J-20-9 for a 70 though.

Rene
66_Malibu

oh really it probably is a 9 that part is pretty worn out and its definetly LD so maybe its a GTO rearend i figured out now that it is a 3.07 non posi rearend so maybe it was switched later I didnt think too many 307 t350 malibus would have a 12 bolt would make sense with all the trouble finding the code was thanks a lot shooter! graemlins/beers.gif :D