so i'm starting my 10 bolt 8.2 differential overhaul in my 65 442. i removed the original anti slip lsd differential carrier from the rearend housing last night. i took apart the case, cleaned & inspected all the parts & its time for reassembly. i do have some questions on clearance & such. there is some light scoring on the inside halves of the case & more scoring where the bottom of the side gear & the inner portion of the cone touch. from what i've read in the csm it is normal from debris that gets trapped inside the case itself. the csm also states that the lsd carrier is good as long as the cones don't bottom out on the bottom of the case. luckily mine hasn't but i decided to plastigauge the clearances just to see how close i am. the closest measurement i took was .018" from the machined surface center of the cone to the smooth machined surface sticking up through the center of the case... NOT the machined surface on the bottom of the case (since that dimension was significantly more) please see my pic for reference.

1) .018" doesn't seem like very much. is this lsd case worth reusing?
2) anyone know what the clearance dimensions are on theses cone type posi cases when they are new?

thanks in advance

 

I don't know the answers to your questions but I do know that a worn cone diff can be machined to bring it back into a functional state. My brother in law had the cone posi in his '68 GTO done back in the late 80s. I think it entailed machining the end of the cone so it would have more end clearance and the cones would grab the walls. Anyway, just a bit of info so you are aware these actually can be rebuilt.

 

took the same measurement on the the half of the case & measured .012" clearance... even less.

 

thank you. do you know who did it?

 

I do the reconditioning here in Ohio... Akron area.

.050 -.100 is about a guess NEW. Your getting close to having a bottom out in the carrier. one more summer of winding roads and that unit will be toast. Jim

Do not forget about the cone outer diameter too. Jim

 

A local machine shop back in the 80s. Likely a lost art for most machine shops these days.

 

I have an 10 bolt 8.2 for sale.

Eaton posi diff
Richmond 3:55 gears
TA Performance girdle/diff cover
New brakes

Needs drums and brake lines
Other than that it's ready to install and run
Has less than 1000 miles

 

Jim, just saw this post. I am taking possession of a 66 Cutlass vert shortly. It has posi so I see you do reconditioning. Can you advise what services you provide so I can possibly contact you if needed.
Thanks
Wayne
Medina, Ohio

 

Complete rebuild / restore. We do not do powder coating ...just not a big fan of the practice... Most muscle cars these days never hit rain let alone salt snow etc for the need for all that.... It looks nice... just always seeing it flake and peel after a few years seems if you do not do it just right it can be more trouble than help.
anyway... posi gear setup narrowing etc.

pm will get you squared away. Jim
J D

 

Jim, thanks for getting back to me. I will make a note.
Thanks
Wayne