Auburn Cone Style LS

[HP JUNKEY]

Hey Jim, Maliburacing member here and I have a question about the GM 7.5" Auburn cone style LS units,,, Everyone tells me that the unit cannot be "rebuilt" but I have heard that you can machine the "end" surface {at the base of the narrow part} of the cones slightly {approx. .030} and re-shim the small spider gears {approx. .030} to get the correct teeth mesh, and this prolongs the life of the unit. Have you ever done this and would you recommend it? OR do you have any "tricks" to make the unit grab better? On the street it will spin both "street tires" but when I put on my ET Streets and hit the track, she only spins the one wheel. Trying to save up for a new/used 8.5" GN rear and just looking to get 1 more season out of this Auburn unit.

THANKS,
HPJUNKEY

[monzaz]

Yes you can machine the cone...BUt you should be shimming the side gear NOT the spider gears... It requires a press to remove the outer cone material from the splined steel spider gear. Then packing very thin shim material and repress back together again.

NOW, this may not help your track issues as the limited slip units from the factory do not have enough preload pressure to compensate for the slicky load you are putting on the unit. YOU need more water when doing a burn out and both will spin and heat equally.
This is why they sell AUBURN PRO series units.

Best to just use a mini spool if your drag racing and cross them fingers -

8.5 will not be any better grip if you do not upgrade to a aftermarket posi unit with at least 400 pound preload.
STOCK posi unit are made for STOCK driving conditions. STREET.

Hope you gather you money before the rear blows. How much do you have saved?

JIm

[HP JUNKEY]

Thanks for the reply,,,, In looking at the side "cones" they look like they are one piece, They come apart??? I do have access to a large press and milling machine so I "think" I can do it, you indicate to put shims in between the steel splined piece and the cone, then repress together? Correct me if I misunderstand.... placing the shim between there, moves the cone into the "cup" of the carrier {or the cone mating surface?}

I have $500 saved now for a 8.5 rear,, but I want to wait until the end of the season this year, by then I should have approx. $1200 and then go on my 8.5 "hunt"

In lieu of doing the machining to my Auburn unit,,, Could I just replace the spring with ones that have more pressure? and are they available? That may buy me some more time.

I drive my Malibu on the street often so I do not want to go with a spool, although I have Moser axles, Aluminum support cover and ARP studs, I am still uneasy about putting a spool in.

OR,,,, do you have a used but good Auburn Pro unit for sale? Mine is a 26 spline Series 2 and I have the "thick" Richmond 4.11 gear set on it. I have a 26 spline Eaton Detroit Locker series 3 carrier, that is in almost new condition that I could sell and that money could be spent to "hold me over" A lot of questions and I apologize, but you have the knowledge I am looking for!

THANKS!!!
HPJUNKEY

[monzaz]

HArd to explain with out pictures so I wil ltry to post some. The outer cone is a totally different softer metal then the spider gear that is a super fine spline press fit. You have to have 2 pieces of metal to hook the cone edge between the v in the teeth. (IT AIN"T EASY but nothing like this ever is) Then a socket in the axle spider gear spline area. YOU will push on the socket to push the center out (your pushing on the NONE SPIDER GEAR TOOTH SIDE) the outer cone is stable on the metal block hopefully right on the outer edge...ONLY about 2-3 finger nails thick.

AGAIN pictures say a thousand words. Jim

give me a few days as it is Easter and we are having family on the weekend.

[HP JUNKEY]

Jim, Thanks for the info, I don't think I am going to do the machine work to the cones, Can I replace the springs with heavier ones and are they available?? That may "hold me over" this season.

THANKS,
HPJUNKEY

[monzaz]

You can put the heaviest of springs in the world and it still will not make the cone grip. You have to understand how the system works to get what I mean.

Lets take 2 dixie cups made of steel so nothing will give... Now you stack them inside each other and they fit snug ...Put more pressure and they fit tight enough you can not spin them...Right?
NOW pull the cups apart and stick a flat washer in the bottom of the cup and now try to put the cup inside on top of the washer...NO matter how hard you push down on the outside cup with the inside cup the bottom of the inside cup hits and the side never get a grip. THIS IS WHAT IS HAPPENING to your posi unit...SO NO MATTER how hard you push it will not lock up just create heat and it will destroy itself. Jim

[HP JUNKEY]

Got it, Thanks for the info!, Now I guess I am on the "hunt" for a "better" Auburn posi to get me through this season, and keep stashing $$$$ for my 8.5.

THANKS AGAIN!!
HPJUNKEY

[monzaz]

Best I can offer is sending us the unit we can do the work for 50.00 AS LONG as the cones are cut-able and not all cracked up from heat. Only way to tell is to tear it apart. Post pictures and or send that unit in a flat rate 10.00 box

so with shiping back and forth and the rebuild 70.00 is the total. - Trying to help.

What series posi unit do you have? Using standard 3 series gears aor thick 2 series on a 2 series posi? Jim

[HP JUNKEY]

I am running a "thick" Richmond set on a 2 series carrier. What would be the turn around time if I sent it to you?,
I will take it apart tonight and take some pics, and post them tomorrow.

THANKS!

[HP JUNKEY]

Hey Jim, WEEELLLL, I took apart my carrier and this is what I found




I thick it is JUNK, Do you have a "used" good one I could purchase?? and if so how much $$$$

THANKS
HPJUNKEY

[monzaz]

Yep look at the cone it is cracked... then the cone is bottomed out WHICH can be fixed BUT the cracked cone can not be fixed.

Good reconditioned 26 spline 2 seires posi is 219.00 Plus 10.00 for the ride. Jim

Just finished reconditioning it and the cones have NEVER hit the case yet...Still factory finish

Can post pictures this evening for you. Jim

[HP JUNKEY]

Thanks Jim, I am interested! Just to be sure on what series I have,,,, I will post a pic of it with the measurement from the mounting surface of the ring gear to the "bench top" I have it setting on, I will also include a pic of my ring gear thickness.

THANKS!!!
HPJUNKEY

[monzaz]

Sounds good. Jim

[HP JUNKEY]

Hey Jim, Here is what I have.............
and how much extra to press on new bearings to the carrier?? So I can just bolt up my ring gear, check backlash and go!!

ALSO, Do you paypal? keeping it on the "down low" from the wifey, I use my buddy's paypal and have things shipped to his house,,,, Happy wife, Happy life!




THANKS

[monzaz]

That is a 2 series carrier measurement for 7.5 10 bolt GM.

The carrier I am selling you is the same as that. ... Amount correct - send away. Jim