[Beige1968GTO]

Hi,

I have a BOP 10 bolt 8.2 four pinion posi unit for sale, used for 3.55 and higher gears. $300.00, plus shipping. Will be posting photos or send me an e-mail and I'll reply with photos.

Thank you,

Ron

[Beige1968GTO]

Sorry for the error on the original post- this posi carrier is for the 3.36 to 4.33 ring and pinion for 8.2 BOP rear ends used in A bodies GTO/Tempest, Skylark and Cutlass, and Firebirds. Price of $250.00 or offer plus shipping. Photos attached.

Please contact me with your e-mail address if you would like higher resolution photos sent to you.



Thank you,

Ron

[RAJ7395]

The pictures show a 2 pinion carrier not 4.

[Beige1968GTO]

then I don't know what I have; could you help me out here? Don't the four gears in the middle mean it's a four pinion unit?

A while back I asked a shop to install it in a 3:23 rear end and they said it would not work.

[69Y97GP]

Here's a pic of a 4 pinion posi. The case is split where I'm pointing. The gears on the sides that the axle shafts go thru are side gears. Not pinion gears. A 4 pinion unit has to have a split case like the one shown.

[Beige1968GTO]

Thank you. Is it correct that the four pinion units were used with 3.36 to 4.33 and the two pinion units used for 2.93 to 3.23 or 2.78 and higher? If so is there a way to tell which this is, the 2.93 to 3.23 or 2.78 and higher?

Ron

[CanAmT/AGTO]

I am interested if this unit if it will accept 3.55 gears, and fit 10 bolt BOP 8.2 in my 71 T/A

[Beige1968GTO]

Apologies to all for my error(s.) This is a 2.78 and numerically lower 2 pinion 8.2 BOP posi. It will only work with 2.78 and numerically lower gears.

With the new description comes a new price: Asking $175.00 or make an offer.

Thank you for your patience,

Ron

[android 211]

Is it good condition or does it need a rebuild?

[gtobird]

Originally I was also interested when I thought it was an original 4 pinion posi. I have a couple of other questions now that I see what it is.

Is this an original BOP posi? I have an original 2 pinion Posi in my 68 Firebird and it looks different than this.

Also, is there rust where one of the bearings mounts (outside of where one of the axles enters)? Wouldn't cleaning this up create a fit problem with the bearing surface?

[Beige1968GTO]

It is in good used condition with the gears and other components looking nice without damage or wear, but I would disassemble, glass bead to remove surface rust and reassemble at the minimum.

Originally Posted by android 211

Is it good condition or does it need a rebuild?

[Beige1968GTO]

From what I think I know no company ever made an aftermarket 2 pinion posi, but I think there were two styles of two pinon posi units made. (I think I recall seeing this in the '68 Pontiac Service manual. There is this type and a "cone" type.) If you have a photo I'd be interested in seeing it.

As far as the rust; if cleaned off with glass beads, it should not be a problem. If you tried to grind of the rust to remove it I would be concerned. Steel expands greatly when it corrodes so little surface metal is lost.

Originally Posted by gtobird

Originally I was also interested when I thought it was an original 4 pinion posi. I have a couple of other questions now that I see what it is.

Is this an original BOP posi? I have an original 2 pinion Posi in my 68 Firebird and it looks different than this.

Also, is there rust where one of the bearings mounts (outside of where one of the axles enters)? Wouldn't cleaning this up create a fit problem with the bearing surface?

[Beige1968GTO]

Price reduced to $150.00 or offer. I can send more photos if you are concerned about what you would be getting and condition if purchased.

Ron

[gtobird]

Okay, now I really am learning something new. When steel rusts, yes the rust itself usually causes the part to grow in diameter, but once you clean off the rust, the good metal itself is of a smaller diameter than original. If the metal is now smaller, how would this possibly work unless you welded and turned that surface area or bushed it before installing the bearings.

Sorry for poking at you one this one.... I actually have a set of 2:56 gears that I could use this for, but with all of the time and effort to set one of these up, I can't see how this one is worth using if it should fail.

['ol Pinion head]

Beige, some helpful info. What you have posted pics of in your first post is not an 8.2 Pontiac 10 bolt carrier.. It most likely is one of the type "O" Olds Anti-Spin carriers. these were made in a variety of "ratio steps" for 28 spline applications, and as a low ratio 31 spline version that was used in '68 applications. The Olds bunch introduced the type "O" Olds differential for '67. it's the rear with 10 bolt 8.4" ring gear and a smooth 12 bolt cover. The first Type"O" used sealed bearing axle splines that are the same pitch 28 spline axle splines as used by the Pontiac 8.2 10 bolt rears. Since the axle splines are the same count and same pitch, can see it somehow making it into a Pontiac 8.2 rearend, though it may have taken mods to do so. Since it is a clutch type posi unit, it is rebuildable with new clutches and with them properly shimmed up. The clutches are same as used in a Corporate 8.5 S spring posi carrier introduced in '71 and used through '87. The previously discontinued GM clutch packs have been reproduced by a fellow in the Olds camp, but are quite expensive. With the drivers side of the carrier standing up on a flat surface, and a measurement taken from the machined ring gear flange down to the flat surface, I should be able to identify. Over the years, have rebuilt quite a few Type "O" Olds carriers and more corporate 8.5 S spring carriers than I can count, Ford 8.8's also used an S spring posi carrier, but this does not look like one.

[GTOLiam]

OPH is probably right again. I sold one of those Olds type O carriers about a year ago and yes it looked the same. The rear was from a 67 or 68 442 and I still have a nice set of 28 spline axles for it I can't use. Perhaps whomever buys your carrier would like to buy these cheap

['ol Pinion head]

Liam, the axles will work in your '67 GTO 8.2 rear if you need them.

[Beige1968GTO]

Ol Pinion Head,

Thank you for the information. Now I know what this is. My apologies to all for advertising it as though it was something it is not.

Next time I'm unsure of what I have I'll start in the tech section. Thank you for the chance to learn.

Ron

[GTOLiam]

Originally Posted by 'ol Pinion head

Liam, the axles will work in your '67 GTO 8.2 rear if you need them.

Yes, thank you! I remember when pulling apart they used some strange kind of sealed bearing on the axle so I didn't even think about it being the same.


Beige1968GTO, the rear I had was a 2:56 and the carrier had the #673 on it.
some info
2.56-2.78 (673) 28 spline axles
3.08-3.23 (671) 28 spline axles <<< Richmond gears fit this carrier ONLY!
3.42-5.00 (588) 28 spline axles
3.42-5.00 (672) 31 spline axles

A guy in a shop out East purchased mine for pro street clients or something... I'll try to find his name and you could contact him

[Beige1968GTO]

Sold! Price TBD