8.2 BOP Axle, has anyone broke one?
 

I am interested in hearing your experiences with the 8.2 BOP axle. Has anyone broke one, if so what let go? Also what's the best 1/4 mile time/60 foot that you have done with a stock 8.2? I'll start it off with my experience with the 8.2. About 10 years ago I broke teeth on the ring and pinion (3.55 factory gears). At the time the car was running high 12's. Best et and 60 foot with stock axle are in my signature. I am considering putting in Yukon axles and the TA1808 rear cover girdle with cap load bolts but not sure it's worth it.

I broke two when I was a teenager in the early 90's, but unless you are doing 6000 RPM clutch drops with a Marlboro red in one hand and AC/DC cranking at full volume through your Panasonic cassette player and sweet-ass Jensen 6x9's, I am not sure my experience is relevant for your situation.

When I raced in NMCA Top Stock John McWhorter(one of the original Comp Cam's owners) was in my class with his 66 or 67 442 4 speed car. It had been a drag car since new and he was in the 11s when most of us were low 12s. But he would often break that rear launching. Usually the gears themselves until he started re heat treating them.

Don’t waste your money doing anything with the 8.2 10-bolt, the soft gray iron housing lacks pinion support. Stronger nodular housing 8.2s are rare and still lack proper pinion support.

Bite the bullet and buy a complete new aftermarket 12-bolt with Ford bearing housing ends.

If you want to stay 10-bolt then there’s no other choice but to upgrade to the GM Corporate 8.5 from a ‘71-‘72 Buick/Olds with bolt-in axles. Nodular housing (like every 8.5 has) and tapered roller axle bearings, upgraded to a 30-spline Eaton posi and Moser axles and then you’ll be set. That’s what I have in my Tempest, the strength rivals that of the 12-bolt just a little lighter weight.

Honestly if I had to do it again I’d just do the 12-bolt and never worry about it.

It seems like everyone spends a fortune on their engine and trans then balks at finishing up with the proper rear axle assembly. :noidea:

I have broke a few but the best one I saw was a 69 GTO the housing split in half from top cover bolt to the bottom cover only thing holding it together was the cover. I was at the purestock race in 17 and a 70 magnum 400 started to do a burn out in the box next to me I just happen to look over and bang every drop of gear oil dumped out on the track in 30 seconds or so. I’m pretty sure it did the same thing.

I broke mine in the city. 455 with 4x heads with a comp 280 cam. Heard a bang. Pulled over and look under the car. I see the driveshaft on the ground with oil coming out the front of the diff. I could see the pinion bearing on the end of the driveshaft. If that tells you anything.

Was I drinking? Probably.

In 1976 i broke my spiders shifting into second gear stock 4bbl 1966 GTO stick

Early 80's 1968 GTO TH400 keept losing axle bearings by the time i could hear them the inner race ruined the axle.

A friend ..circa 1976.. had a 1966 GTO 389 4bbl RAIV cam stick car it had a 12bolt 4.11 i broke the drivers tube loose from center section hitting second gear in that, quickly swapped lanes on me

Good Times

I broke one on the drag strip launching a 4 speed. Broke the front of the housing and the driveshaft came out with the pinion still attached. Everyone loved that I dumped 2quarts of gear oil on the track.

I ran a Ford 9” in my ‘64 GTO bracket car with a mild 455 running in the low-12/high 11s. It wasn’t a fancy higher strength one, just a cast iron carrier with a Detroit Locker and 31-spline resplined stock axles, built off of a stock Ford axle housing by Currie back in 1987. I later had a back brace welded to the housing to prevent it from bending while launching off the transbrake with 10x28’’ slicks, never an issue with it.

It was fun watching my competitors breaking spiders and axles with their stock 12-bolts or twisting the center section loose from the axles due to weak factory rosette welds on 2nd-gen F-bodies equipped with Corporate 8.5s.

The new aftermarket 12-bolts are far superior to the stock ones. A nice aftermarket Ford 9” with the proper upgrades is a great way to go as well.

Forget about the 8.2 for anything other than a proper restoration.

Now cue all the guys who have run 10s with their 8.2 rear. :rolleyes:

You guys are ensuring that my next big purchase for my car is an 8.5 Moser setup. I’ve been keeping an eye on the 4 pinion 8.2 in my car and I don’t have confidence in its longevity.

The title of the thread should have been, "8.2 BOP axle, anyone not broken one?" ...........:D.........LOL

Put a 9 inch in, and have the luxury of easy ratio changes, (swap punkins) while having enough strength for almost anything that is streetable. There are many more 9 inch rear axles, and parts available than 12 bolt parts, and pieces. The 9 inch is like the SBC of rear axles, everyone has them, and they're relatively cheap, while being reliable. My next project will have a full floater 9 inch under it, even if an axle should break, the wheel will stay with the car.

If you're going to swap to an 8.5, make sure the axle tubes are welded more than the plug welds GM used. I've seen multiple 8.5 axles snap the factory welded tubes off the center section, even with street tires.

Believe it or not my 70 GTO came with a 12 bolt rear, its and original 455 HO car.
I’m like ? Until I ran into my buddy with his all original 1970 Ram IV GTO who bought it brand new. He had no clue it had a 12 bolt rear. Until I mentioned it.

I broke my original 8.2 going 25mph. Loud bang which was the ring and pinion. Car was going 13.1 on street tires at the time. I went 9" with no regrets

The weakest link in all the Pontiacs where in the Firebird or GTO has always been 10 bolt rears weather its a 8.2 or 8.5 rear. Here’s what you have to think about. The factory fire birds in GTO‘s made at most 350-360 hp. Those rear ends could barely handle that. You hear all the stories.

Yes, it made quite a noise and mess!

Dennis

8.5 definitely better of the 2. When you get into the 650 + hp range and something you drag race is one they become weak link. Don’t mean occasional trips to track.

8.2" survive just fine with the 350 motor.
I dunno a out 400 motors, probsbly okay with either stick or Auto.

428 and 455 motors require a 12-bolt, or smartly set-up 8.5, or go Dana60 to remove all doubt. The 9" is all aftermarket stuff to play so the 9" cost ought be compared to Dana S60 or 12-Bolt.

I was first run of the night.
Broke the stock pinion gear in half right at the tree
Car wouldnt move forward but would move backwards
so it was pushed off to the side,next to waterbox and I crawled under it to remove
the guts so it could be flat towed home.
I spent the entire night under the car watching them launch from an ants prospective.
No way would the safety karens let that happen today.
Next step was aftermarket 456 gears and it did fine.

I've broke every one I've ever had behind a 400 or larger engine!

Broke the one of the top eyelet off mine in high school doing a 3k neutral drop with protrac stickies. Dumb kid back then. Fun though.

My buddy with 70 Ram IV judge broke his. Just Gears though. This is funny when I pull the cover. NO ! Rear end oil. I’m like Greg your supposed to check your rear you know like checking your oil. LOL

This is even funnier, I talked him into buying the Judge after he sold his 68 Camaro. Went to Pontiac dealer with him… but I order it, Ram air IV and suspension package. Turbo 400 trans. On the way home he says Lou you think black is going to look good, Don’t worry Greg your going to love it…LOL

Jinkies...this tread giving me more Grey hairs...i guess I'll be moving that rear end upgrade higher in the growing queue...I had no idea it was that weak

1) Broke the driver's side Rear Bearing cap.
2) Swapped to whole rear out for another 8.2 BOP which broke one of the axle shafts, (that was scary).

Replaced the rear axle for a 2.73 rear axle and small tires and had to issues with that
10 bolt rear.

Swapped the 2.73 rear axle for the original "Jim Wangers 64 GTO 4:33 (red car).
No issues with that. Later swapped the rear to Tenny so he had the correct real axle under the read car and installed a Ford 9" rear under the car. "N" case center section
and later bought from (Larry with the 1961 Catalina SS car) a Strange "Bullet Proof"
Ford center section. I now have two of those (one under the car presently) along with some gears from Larry K and Joe Z, so have a string rear set-up. The center sections use a Moser built rear housing and I have installed 4 wheel "Explorer" rear disc brakes.

That being said I was goos at swapping BOP 8.2 complete axle assemblies under the car when a teenager.

8.2 BOPs were not worth the money to sell them for scrap metal.

Tom V.

Tom V.

1) Broke the driver's side Rear Bearing cap.
2) Swapped to whole rear out for another 8.2 BOP which broke one of the axle shafts, (that was scary).

Replaced the rear axle for a 2.73 rear axle and small tires and had to issues with that
10 bolt rear.

Swapped the 2.73 rear axle for the original "Jim Wangers 64 GTO 4:33 (red car).
No issues with that. Later swapped the rear to Tenny so he had the correct real axle under the read car and installed a Ford 9" rear under the car. "N" case center section
and later bought from (Larry with the 1961 Catalina SS car) a Strange "Bullet Proof"
Ford center section. I now have two of those (one under the car presently) along with some gears from Larry K and Joe Z, so have a string rear set-up. The center sections use a Moser built rear housing and I have installed 4 wheel "Explorer" rear disc brakes.

That being said I was good at swapping BOP 8.2 complete axle assemblies under the car when a teenager.

8.2 BOPs were not worth the money to sell them for scrap metal.

Tom V.

Once I started making more power, above 650 hp. Back then wasn’t any aftermarket rears available like there is now. Had rear end done to handle the power. Which meant Chrome Molly axle tubes. Welded and reinforced. Mark Williams axles, with clip Eliminator‘s. Axle tube braces. Rear end cover that gets torque and puts pressure on the main caps, and pro gears. Kinsler has same set up 12 bolt and runs mid 7’s. The Ford 9’s is ok but its allot heavier then a 12 bolt. So when your chasing ET’s you go with the lightest. Been running car with that 12 bolt for 28 years, well worth the investment.

You forgot the Kraco amp pushing those Jensen Triaxles. !

It sucks that GM had weaker rear ends and 4 speeds than the Ford and Mopar guys. A LS6 should have something better than a Muncie and 12 bolt.
Myself, I broke a 10 bolt posi with a 400. Went to a 9" with 400 and did not hurt it. 455, with 9", broke Trac Loc then Detroit Locker. Went spool and MW axles. Eventually broke the 31 spline MW axles. Bent the snout out of my housing.
Straightened it and installed back brace, Moser Thru bolt big pinion, 40 spline Pro gear center section and 40 spline gun drilled, star flange axles.
If I had to do it all again the lightweight Strange Dana 60 might be the way to go. Light, full floater and they have a bolt on cover so they at least look kinda stock.

The word back then was the axle tubes would bend causing everything to flex. I bought a 12 bolt cheap, when we checked it, axle tubes where bent. I brought it back and got my money back. Thats when I decide to go Chrome Molly axle tubes. Plus put axle tube braces. I just seen so many rear end blow. All I could picture is going though traps at 140 mph and have one let go, thats when I decide to spend money and make as bullet proof as I can.

If you want an 8.2 to last forever the key is .... open diff, auto trans, no racing :)

I completely snapped the bearing carrier off of the housing in an 8.5 2nd to 3rd gear change on the track and a ridicuiously loud bang. Had a ford 9" under there since.

8.2 BOP behind my 455 here. Spent the 1st 20 years of ownership with a 4:56 gear behind a 3500 stall convertor. I never, repeat never left a stop sign or light without leaning my mark and routinely beat it like crazy including many long burnouts on uneven road surfaces where I thought "Yep I'm sure that one broke an axle."

I swapped my convertor with Lee Atkinson (who wanted to try a higher stall in his Firebird) for his Huges BOP 25. After about 5 more years of abuse, my posi gave up and began peg legging, I bought a used 8.2/3.55 from a forumite who claimed it was rebuilt but it wasn't. Had a shop rebuild it and the trans and put it in along with new axle bearings 10 years ago. The trans rebuilder set up my trans with good firm shifts and I've been driving it ever since. All told, I've owned the car for 35 years and besides the posi wear, the rear end has never been an issue.

Perhaps being an automatic on street tires helps but the 8.2 rear end is the last thing I've ever worried about.

@Tom ; i bet that 2.73:1 was a whole lotta fun. My 2.73:1 12-Bolt was great fun for drives involving the highway.

LMAO

GT

I’m still laughing LOL only because it sounds familiar.

LOL….That is some awesome 10 bolt carnage!:eek:

My buddy said I should carry a bag of floor dry in the trunk so when the 10 bolt’s shrapnel comes through the floor it puncher’s the bag and helps soak up the gear oil. :pound:

It is a solid idea LOL

https://m.youtube.com/watch?v=wk86GV...eHBsb3Npb24%3D

Broke the spider gears and twisted both axles using 9 inch slicks. 12.7 at 107mph. Replaced everything with Moser axles and Moser's Ford 9 inch.

Back in the early 70's, my stock 3.55 rear on my pattern 69 Judge with 4spd was thrashed many times in street races. Never had an issue until one day I discovered one of the rear wheels seemed very hot to the touch. Finally looked to the rear and found the axles were very sloppy. Took out the axle on one side and the ball bearings just fell out onto the ground. Couldn't believe it. Took it to a local auto parts store to have another bearing pressed on. Was told the old bearing spun on the axle and was recommended to get a new one. I didn't and had the new bearing pressed on the old axle. Changed both axle bearings and never had another issue. The rear held up fine, but I wasn't hole shotting the car on a dragstrip either. I think for street use many of these rears held up fine with stock HP motors. However, if you began to gain more HP, that could be another matter.

Would that 8.2 with 3.55s in a 69 Judge be an nodular (N) rear axle?

Is this 8.2 BOP the same housing and axle setup used in the big cars? Everybody's comments seem to be about Firebirds and GTO/Lemans. I have a 66 Catalina and I remember many years ago looking to get a better ratio gear for it and places like Summit and Jegs listed BOP components but something I can't remember now was different than what I had. I haven't looked lately but back then (late 90s?) the only diff parts for a 66 full-size had to be used OEM. Anyone know anything more about that?

A '69 Judge optioned so it came with 3.55 gearing & Safe-T-Track, would a Nodular 8.2 PONTIAC center housing & the late 60's 4 pinion PONTIAC 8.2 carrier.

No, the early Pontiac 8.2 rears were not used in the '65-70 Pontiac B series. All US produced '65-70 Pontiac B series rears were 8 7/8" '65-70 P Series rears. Big Olds also used a version of the P series rear. believe that was '66 model. Im NOT an Olds guy, & its been near 25 years since I crawled under a manual trans '66 big Olds to drain the r/e lube & ck out that r/e's ring & pinion.

never broke an axle on an 8.2 but started stripping the ring gear teeth right at 1.59 60's....always ran a diff cover with the bearing cap preloads, seemed to help quite a bit.... nothing saved the ring gear after 1.59 or less 60's

What are the torque/hp limits of an 8.2? I have to imagine they were close to the limit with the stock 400 application since they stepped up to a 12 bolt with the 455s in '70.

Wondering what the likelihood is of my rear end (3.55 4-pinion Nodular) surviving a launch on street tires vs. drag radials with 450ft/lbs of torque at the rear wheels? Trying to decide if I should just bite the bullet and replace it before I go beating on it.

Have not broken an axle but came very close to it. After many years of street tire drag racing, no issues but then decided to put slicks on. 455 with TH350, 3.55:1 rear gears. First pass went really well, the second pass not so well, noted a 1 wheel burnout. When I got home took the cover off and pulled the axles...one axle was twisted at the splines. Differential was done. This was an old cone style unit. Machine shop said it couldn't be rebuilt.

Currently running 9" with wavetrac and currie 35 spline/3.50:1 setup.

Replace it before you give it another thought. If it’s the original rear then stash it under your workbench and if not sell it to recoup some of the cost of a good aftermarket 12-bolt.

Why chance ruining your good and valuable N case 8.2 just to end up buying what you knew you needed anyway ?

It would probably be helpful to mention which version of the 8.2 got broke, a grey iron 8.2, or a N case 8.2. N case should be fairly strong versus the grey.

The Tempest in Post #15 is Paul Glasgo’s super quick Magnum 400 tribute. Paul’s Tempest Hardtop (called T-37 when introduced in Spring 1970) was a 350 2-bbl/ TH350 car originally, so had the gray iron center section with 2.56 gears. There are a couple of magazine write-ups about the car online to read more about the build. At the 2017 Pure Stock Drags Paul pretty much destroyed the gray iron center section during the burnout, but this is after 10 years of drag racing the car at our race, F.A.S.T. races, and other events (Hemmings Muscle-palooza’s, Tripower Nationals, etc.). From our information (the tech card every racer fills out at the race), Paul listed the trans as 4-speed and the rear end as 3.90, so a recent change from the TH400/4.10 he was originally running in the car. That 8.2” 10-Bolt took more of its fair share of abuse and the new 4-speed probably was the final straw the broke the 10-bolt’s back.

My carnage story...my ’70 Lemans 4-dr sedan came from the factory with an M20 4-speed trans and a 3.23 Safe-T-Track 8.2” 10-bolt rear end (with the grey iron center section). It survived well behind the original 350 2-bbl engine. In 2015 we swapped in a rebuilt ’70 YH code 360 hp 455 (small valve) from a Bonneville that dyno’d at 390 hp and 512 lbft of torque which that caused major havoc to that rear end. All it took was one eased-in full throttle blast from a roll in 1st gear that brought on the most extreme wheel-hop I had ever experienced for just a split second. I got out of the gas immediately and there was a clunk and a side-to-side shimmy as I came to a complete stop. After letting it sit a minute, I then just eased it back home. Fortunately, it didn’t make any more noises or lock up on me. The 10-bolt came out soon thereafter and we sent a 3.07 12-bolt from a ’70 GP out to be rebuilt along with a new driveshaft made. We haven’t opened up the original 10-bolt rear end yet, but we know there was some damage done, maybe a tooth or two off the ring gear…?

Dennis

Maybe someone can answer some more questions I have, that could be helpful on strength variations for the 8.2’s for street duty, and which upgrades are worth it for more street and strip. We went yesterday too a large salvage yard that specializes in 60s and early 70s GM cars. Must have been a couple hundred Chevelle’s. In doing so we were going through piles of rear ends, looking for N case 8.2s, and 8.5 from a 71 or 72 Olds or Buick, or a 12 bolt that could fit a friends 66 Tempest. From going on the scavenging hunt and 3 of us looking thru piles and piles rear ends, comparing notes, maybe someone can clear up some things we concluded we don’t know.


1.Does the N case 8.2 have a stronger alloy axles? One of the guys that was with me thought he remember they did.

2. When was the N case introduced??. We could not find info on anything before 68 for a N axle. We found a 68 N with 3.55s at the yard. One internet source said the N case came out in 66 though?

3. One of they guys that I went with said he talked to someone that said all 4 pins posi’s are N cases. But we have an untouched 67 4 pin with 3.36 that is not a N case. So that must not be true. But maybe there were not N case available at all in 67, and the 68 3.36 was an N case? Or did the 3.36s ratios never come with a N case. We all concluded we don’t know.

Appears to me the N case is the difference between shearing teeth off the ring gear, or ripping the pinion out of a grey iron case.