The big Buick Olds Pontiac 8.5 10 bolt info/tech thread and POLL

[carcass]

B.O.P. bolt in axle 10 bolt tech.
Forgive me if this has been discussed before, but I'd like some help compiling all the information and tech for the Buick Olds Pontiac B.O.P. 10 Bolt bolt in axle press bearing rearend housings that some of the third generation A bodies seem to have gotten.
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Moser engineerings answer.
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I called Moser on 4/25/2013 to inquire about aftermarket axles for these housings and I got a tech guy who was very abrupt in saying that "we have'nt seen anything like that around here" and then went further to say that "you would have to send an axle to us to have us copy it" this particular tech guy has apparently never heard of this type of ten bolt housing, I think this is not accurate for everyone at Moser considering probly 50 million of these were made over the years of the A body.
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I'm going to write a letter to Moser online to inquire about these rearends further in hopes to get some answers, here are a couple quotes from this site about guys getting these exact axles from Moser.
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w451973 wrote:
How much power do you plan on making ? You already have the better 10 bolt with the bolt in axles. You can get the good axles with better bearings from Moser. A 9 inch is great to brag about but alot of people that buy them don't even have the power to break a 10 bolt. They only got bad reps because nobody made quality parts for them years ago like they do today. You also don't want to forget the extra weight of a 9 inch over your 10 bolt.

The 10 bolt in my 75 Cutlass I had handled many 10:60-10:70 passes without any problem.
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JB2wheeler wrote:
I have a BOP rear in my 74 Elky from the factory. I upgraded it with a 3.42 posi and Moser 30 Spline axles. Funny thing, you must have got the janitor on the phone. JB
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Strange Engineerings answer,
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So then I called Strange Eng. and talked to a very knowledgable guy named Edwin at the tech dept. and he was fully aware and versed on the B.O.P. type ten bolts with bolt in axles however he stated that "Strange Engineering does not make axles for these press bearing 8.5 ten bolts because the diameter of their axles is actually larger than the surface where the pressed on bearing would need to ride so they would have to make a new forging or machine down an intire axle to get the bearing into place, and that the bearings on these axles from GM are inferior due to the small diameter of the bearing itself."
Edwin did tell me that Superior Axle and Gear makes a stock replacement axle for these housings.
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I called Superior Axle and Gear and couldnt even get through the phone just rang and rang.
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So I ask all who have info on these and can get part numbers for axles, wheel bearings and tech on if the carriers are the same, and if so do they need some sort of conversion carrier bearing. and also if and how we can convert to 30 spline axles and what EATON DETROIT carriers will work.
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My 1974 Malibu has one of these housings as does my new to me 1976 Malibu classic, I took the cover off the rear of the 76 today to check the gear ratio and state of the oil and gears themselves, and this is what I learned today. 4/28/2013
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The rear cover on both my B.O.P. style rearends looks like this.

[img][/img]
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Here is the rear cover off of a 1973 Nova 8.5 ten bolt housing,
[img][/img]
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here is the two covers layed together which all ten bolts lined up just perfect
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[img][/img]
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so the only difference in the covers is the c shaped cutouts on the B.O.P. version, the felpro gasket i got for a standard C-clip 8.5 ten bolt works for the B.O.P. version as well and I used it to put the cover back on today. The regular ten bolt cover can be used on the B.O.P. housing but not vice versa because the C-clip housing requires the oil channels in the rear cover to direct oil down the axle tubes to feed the bearings here----
[img][/img]
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Here is a photo of the same area on the B.O.P. ten bolt housing it does not have the need to feed oil to the bearings as they are sealed bearings.
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[img][/img]
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more to come

[ant7377]

The Timken part # for the axle bearing is "Set 9" the corresponding seal I would have to check,I don't remember right now.

[carcass]

Here is the felpro gasket on the cover for the C-clip 8.5 ten bolt out of a 73 Nova you can see how the cover has the slits in it where oil goes into the axle tubes to feed the axle bearings.
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[img][/img]
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Here is the same cover on the B.O.P. housing
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[img][/img]
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[img][/img]
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so my theory is that a Moser, TA, Jegs, aluminum girdle type rear cover for a regular C-clip axle will work just fine on a B.O.P. housing as the the stock type steel C-clip cover could be used on a B.O.P. housing. Heres a photo of it on the B.O.P. housing,
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[img][/img]
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and a photo of the irregular cover in the same spot.
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[img][/img]
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Next up a carrier bearing cap comparo.

[carcass]

Here is a photo of the bearing cap on the 1976 B.O.P. bolt in axle 8.5 ten bolt housing,
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[img][/img]
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here is a shot of the 1973 Nova C-clip 8.5 ten bolt carrier bearing,
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[img][/img]
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next up axle tube end photo comparo

[carcass]

another thing learned was that you can tell right away if you have the bolt in axles because the ends of the axle tubes next to the brake backing plates are not tapered down like the C-clip housings are.
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and that the four bolts that retain the backing plate are T bolts stuck in from the back.
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Heres a photo of the end of my 1976 Malibu B.O.P. ten bolt housing end,
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[img][/img]
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you can see that its not tapered but straight into the backing plate,
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here is a photo of the 73 Nova C-clip ten bolt housing end sorry theres no backing plate on it for comparison, my twelve bolt in my Nova has housing ends just like this,
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[img][/img]
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By the way my 76 Malibu has 2.73 gears

[carcass]

I got on TA performances website looking at aluminum rear covers and they list a B.O.P. rear cover but it looks just like the chevy one,
heres a link
http://www.taperformance.com/products.asp?cat=48

[carcass]

And low and behold I searched Timken set 9 on the web and the second link down was for Moser Engineering and they CARRY THE TIMKEN SET 9 BEARING KIT WITH SEALS!!!!!!
http://www.moserengineering.com/other-parts/bearings/bop-and-jeep-tapered-bearing-timken-set-9.html
kinda funny how the tech guy on the phone knew nothing about these B.O.P. rearends and they carry the friggen bearings and seals but it does say on their site that its for a Jeep model 20.

[carcass]

I pulled the axles out of my 74 when I put the mini spool in it and wish I would have taken photos of the axle bearings and the seals and the retaining plate for the axle. The retaining plate is made out of basically sheet metal. I wouldnt trust it to take much abuse.
the nine inch housing retaining plates I've seen are like a 1/4" thick.

also my buddy just spit an entire axle and brake and tire assembly out of his Monza that has a Furd 8.8" housing that has welded on C-clip eliminators, the axle retaining plate bolts sheared off and the whole kit and caboodel came out of the car. So I wouldnt say that they are fool proff.

[carcass]

here is Moser's page on 73 to 77 laguna axles, but it only talks about C-clip style axles.
http://www.moserengineering.com/axles/gm-axles/gm-car-axles/1973-1977-chevelle-gm-laguna/10-bolt-30-spline-fits-1973-77-laguna-monte-carlo-chevelle-malibu-cutlass.html

[carcass]

Summit racing Timken Set 9 bearing link
http://www.summitracing.com/parts/tmk-set9/applications

[1973 454 MONTE]

here is Moser's page on 73 to 77 laguna axles, but it only talks about C-clip style axles.
http://www.moserengineering.com/axles/gm-axles/gm-car-axles/1973-1977-chevelle-gm-laguna/10-bolt-30-spline-fits-1973-77-laguna-monte-carlo-chevelle-malibu-cutlass.html

but ours are 28 spline.


says an aftermarket 30 carrier has to be bought.

[jerry46765]

Lots of info here, but what are you trying to do / goal?

[carcass]

here is Moser's page on 73 to 77 laguna axles, but it only talks about C-clip style axles.
http://www.moserengineering.com/axles/gm-axles/gm-car-axles/1973-1977-chevelle-gm-laguna/10-bolt-30-spline-fits-1973-77-laguna-monte-carlo-chevelle-malibu-cutlass.html

but ours are 28 spline.


says an aftermarket 30 carrier has to be bought.

Sorry about that link its a page ahead of Mosers listing for both 28 spline and 30 spline C-clip axles for 73 to 77 A bodies. Moser's catalog lists C-clip axles for our cars but not the press bearing bolt in type axle, but theres some folks saying they have gotten such an animal from Moser, an aftermarket,alloy, non-tapered 3/8 wheel flange 28 OR 30 spline bolt in press bearing axle.

Reportedly our 73 to 77 A bodies could have come with either spline count 28 or 30, there was even some odd ring gear diameters, such as 8 7/8" or something.
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Heres a better link to all I could find at Moser for our cars,it lists two spline counts 28 and 30, the 30 most likely would require an aftermarket 30 spline carrier, but maybe not if the rumours are true about some stock cars getting 30 spline axles.
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http://www.moserengineering.com/axles/gm-axles/gm-car-axles/1973-1977-chevelle-gm-laguna.html
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[carcass]

Lots of info here, but what are you trying to do / goal?

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Thanks for the reply,
My goal is to dispell any misinformation and compile correct information and part numbers and links for aftermarket support for these rearends, and also to collect data regarding what cars got these rearends and why. If its humdrum please forgive me but I think its worthy considering the tiny amount of info I could find on this website or any orther. And the fact that many of our cars got them. Also these rearends are touted as being "better" than the standard C-clip rear, if this is true, I want non tapered betterr aloy axles hopefully 30 spline with 1/2" wheel studs, a new Eaton Posi or True Trac, and an aluminum support coverr, and new wheel bearings of the best quality. And a list of compatible OEM parts such as carriers from late model 94-96 Imaplas and newer disc brake packages. It is my opinion that a sticky for this is well in order with the amount of these rears made and the small amount of info available, I haver personally seen two other cars with these rears in a junkyard, one 74isch Grand Prix and one 74 Olds 442, and yet both of these cars had a standard C-clip style rear cover, but they both had bolt in axles. And I have two myself, both came in Chevy malibus, yet both of these had the odd shaped rear cover, so what the heck is going on?

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[carcass]

Moser lists C-clip ten bolt axles for 73 to 77 A bodies right in their catalog, but these axles WILL NOT WORK IN PRESS BEARING BOLT IN AXLE TEN BOLTS due to the bearing surface being ground to the dimension required to act as the race for an open roller type bearing that requires 80/90 weight lubrication.
Literally all the third Gen A bodies I have crawled under (only four) have had the bolt in axle ten bolt, WHY CAN'T i FIND AFTERMARKET AXLES FOR THEM?????

[Sleddogg]

Great post, cleared up some questions I had. Thanks.

[carcass]

Heres a bolt in axle for 2nd gen A bodies at USA standard gear, trying to contact them but they don't list their contact info on their website.
http://usastandardgear.com/ProductDetails.aspx?ProdID=7720

[carcass]

Interesting info page about oldsmobile axles, halfway down is the 8.5 bolt in style cover and gasket description, and the years and cars that got them.
http://www.oldsmobility.com/old/10bolt-tech.htm

[thatfnthing]

Heres a bolt in axle for 2nd gen A bodies at USA standard gear, trying to contact them but they don't list their contact info on their website.
http://usastandardgear.com/ProductDetails.aspx?ProdID=7720

That's 'cuz they want you to buy their stuff through one of their vendors. When you click the "Buy Now" button, you actually get the distributors page.

[JB2wheeler]

I had my speed shop do my rear end modifications and I can not guarentee that they did the work they claimed they did because the rear has not been visually inspected since they did the work. JB

[jerry46765]

Is there a side by side picture comparison of axles?

[jerry46765]

I went back and reread this again.

What is better in the BOP pressed bearing unit over the corporate 8.5 c-clip 10-bolt?
Bigger axle bearing?
Different style axle?
Bigger diameter axle?
Different axle spline?
Different carrier bearing?
Different style diff/spider gear configuration?

It is interesting that a non-c clip 8.5 inch exists but if it's uncommon, and parts are hard to acquire, then maybe there is a better choice.

Thanks -

[carcass]

I went back and reread this again.

What is better in the BOP pressed bearing unit over the corporate 8.5 c-clip 10-bolt?
Bigger axle bearing?
Different style axle?
Bigger diameter axle?
Different axle spline?
Different carrier bearing?
Different style diff/spider gear configuration?

It is interesting that a non-c clip 8.5 inch exists but if it's uncommon, and parts are hard to acquire, then maybe there is a better choice.

Thanks -

Ah Yes!!
These are excellent questions.
I wish I had a side by side axle photo comparison for you but I have had the axles out of my 74 with the bolt in axles.
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The bolt in axle is the same diameter at the tapered area 5inches down from the splined end as the C-clip style axle is, the only difference I could see was that there was no c clip groove and there fore the axle is a little shorter like the end just wasnt included. The diameter at the end where the pressed on bearing resides went unmeasured when I pulled mine out, sorry, but I think that the bearing area is a different diameter than the c-clip axle is.
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I don't know and wish some folks would chime in about the axle bearing itself and how it wears verses a C-clip style bearing.
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From what I understand all 8.5 ten bolts regardless of bolt in axles or c-clip axles can use the same carriers but one needs to be mindfull of spline count, my B.O.P. style rearend has 28 spline axles, but some may have gotten 30 spline, and later cars such as the 94-96 Impalas got the 30 spline carriers, and as we all know a 28 spline 8.5 ten bolt carrier can be upgraded to 30 spline axles if you get both in combination.
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The carrier bearings are the same from what I understand, the difference between the two housings really lies in the wheel bearing area, and I have yet to get an aftermarket company to confirm that they make EITHER 28 spline or 30 spline non tapered better aloy axles, or even a company to confirm that you can get stock replacement axles for these housings.
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Not to muddy the waters further, but such oddities as 8.6", and 8.7" bolt in axle B.O.P. rearends exist some with weird twelve bolt covers, from what I've read these were mainly used in 68-72 Oldsmobiles. Possibly called the type "O" rearend.
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to answer the question what is better about the bolt in axle ten bolt. IMHO I would say absolutely nothing. The simple fact of bolt in axles does not make it better if you can't get good non tapered axles, and the axle bearing itself is questionable in longevity, and expensive and somewhat hard to get, and the part numbers are screwy, the whole "timken set 9" thing doesnt seem to necessarily include our gen 3 vehicles in the part descriptions. And the bearing retainer itself is made out of thin sheetmetal like stuff and is questionable as well. I would fully trade anyone right now for a c-clip version of the ten bolt. At least then I could get good axles and convert to 30 spline and get new wheel bearings easily, And theres no way in heck I'm gonna brake a Moser C-clip axle they are beefy, I'd trust a Moser C-clip axle to stay in the car long before I'd trust an undefined 28 spline 45 year old axle with a sheetmetal retainer to stay in the car any day.
Here is a photo comparison of stock GM C-clip twelve bolt axle next to a moser replacement c-clip axle, the bolt in axle I pulled from my 74 Malibu had the same porosity and tapered area as twelve bolt cclip axle just with no c-clip end.
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[img][/img]
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[img][/img]
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These photos are for comparison and in no way imply that a bolt in axle is available from Moser.

[carcass]

heres an ebay listing for 8.2 bolt in axles, I contacted the seller about this and added a link to this thread, hopefully he'll be able to shed some light on better axles and the coresponding wheel bearings.
http://www.ebay.com/itm/NEW-PONTIAC-BUICK-BOLT-IN-AXLES-10-BOLT-8-2-A-Body-GM-442-Skylark-GTO-FIREBIRD-/221217456006?pt=Motors_Car_Truck_Parts_Accessories&hash=item3381967f86&vxp=mtr

[texan01]

Whats interesting is my '77 California built parts car has a BOP axle in it (I think) 2.56 ratio, and my Dec 76 Arlington built car has a c-clip 2.56 axle in it. My December 75 build 76 (Arlington built) had a 3.08 BOP axle in it as well.

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