Oldsmobile 12 bolt rear end identification. 31:1 - Tooth Combination 43,13 Ratio 3.

Oldsmobile 12 bolt rear end identification Package includes; I have what I believe to be an Olds 12 bolt differential for an A-body that I am trying to ID and possibly obtain a posi unit for. 5 but gears not interchangeable with chevy 10 or 12 bolt I have a 72 Monte with7. So guys with 1978 and up G bodies had a few options: beef up the 7. 4 Olds: Cover Bolt Count: 12: Ring Gear Bolt Count: 10: Ring Gear Bolt Size: 7/16 right hand thread / aftermarket gears 7/16 left hand thread: Axle Spline: 28 bolt in axle 60 degree spline 31 Rear Axle Identification. not 9 3/8 that is the Buick rear and olds full size 12 bolt cover rear ring gear diameters. Tag usually mounted using the upper right cover bolt . Now it I do know it is a Buick, Oldsmobile, Pontiac rear end because it is the typical 10 bolt rear end and pumpkin. 2 10 bolt is great little rear end, I have a 1970 Chevy Nova that runs 11’s through the quarter with a 1:56 60′ time. This is not the 10 bolt ring version both cover and ring have 12 You can identify a truck differential by the smaller, 1968 and 1969 Olds F85 and Cutlass (some) with “C”-type axles. 55 wv xv gto 455 ho only(c-type axle) 12 bolt 1970 3. 7digits and will start Expect to pay upwards of $1000 for one of the desirable axles (ie, Chevy 12 bolt) with posi and a popular gear ratio. Thank you Foe identification purposes, the Buick and Olds rears have pressed on axle shaft bearings and the Chevy rear Incidentally, this cover only needed 10 zinc-plated bolts, because GM switched from the 12-bolt rear to a 10-bolt unit. 5 rear end, It is known as the "O" axle and was used in the Olds Cutlass from around '68 to the early '70s. I do see a TR code for a 68 Olds F85 c-type open rear w/2. http There's a lot of crossover within GM on the housings as the Chevy castings were used in Olds ,Pontiac and Buicks before Rear-end track width measurements of classic American cars including Chevrolet, Ford, and Mopar vehicle rear axle widths Newest [ December 12, 2024 ] The Key to The Olds 12 bolt looks almost like a Chevy 8,5 10 bolt. 5 Scott I found this note : 1969 - 1970 All 1969 O axles use a sealed ball bearing as you describe. 3 that I have and making new brackets n stuff. Share If I can't find a set of 3. I traded a 10 bolt rearend to a guy 2 years ago for a 12 bolt (he traded cause the rear end I had was a bolt in to his 56 Chevy). May 30, 2024 06:59 AM by Have Oldsmobile rear end. In 1971, GM instituted a standardized "corporate" If it is A 12 bolt BOP they had 8. It has an odd-ball bolt pattern on the cover, and the cover is almost completely round. Call 800. Another reason Minore went to these guys for the rearend resto is Rear Axle Identification. 55 ratio E=Eaton posi 0526=May 26th assembly date K=McKinnion (Canada) axle plant Edit: FYI From 64-72 there were 4 different rear ends used in a Cutlass/442. com. This information should help you locate the Auburn Gear differential model Scott I found this note : 1969 - 1970 All 1969 O axles use a sealed ball bearing as you describe. It does not have c clips, the axles bolt in. The code will tell you what was originally installed in the housing, but nothing about any 1958-1970 Full size Chevy rear differential identification chart. $6. 875 in. 5 O-Type (Oldsmobile) - 12 bolt cover with 8. and not the 12-bolt cover 10-bolt ring gear Oldsmobile rear that isn't a real 12-bolt. 394139, which shows to be 1967-1969 A-body. 5 rear. Casting no. monzaz Power Poster Posts: 1002 Joined: Wed Nov 14, 2007 12:56 am Location: RICHFIELD, The Strange GM 12-bolt rear end is available in any state of completion from a bare housing to a fully built differential for certain popular Ford 8. Ring Gear Axle This is in my 70 GS 455, it has 12 bolts on the rear cover, has the 8. 90 and 4. 5-inch-diameter ring gear with 10 attaching bolts. 5 1971 1972 Olds cutlass original rear end. 5/7. In Stock. 5in 10 bolt axle The 7. I couldn't find any axle codes on the tubes Chevy 10- and 12-bolt axle assemblies have been standard equipment on GM passenger cars, muscle cars, and trucks for decades. I have a 72 Cutlass where the rear end was changed to a type "O" 12bolt cover/10bolt ring. 73 none coz fb 1970 So, if you have a 1970 12 bolt olds the axles will be 28 spline and have OILED axle bearings and the SEALS will be on the axle shaft. The 1970 rear end differs from the 1971-1981 rear end. jwesley4152 on Dec 2, 2024. BOTH these rears were Bolt In Axles and both were 31 spline 45 degree cut axle spline angle. 75-inch The rear axle identification code consists of a two letter prefix indicating the gear ratio, four digits indicating the assembly date as month/day, and a single letter suffix indicating the manufacturing location. '65 Cadillac, '66 Buick Wildcat, '66-67 It is a 12 bolt rear end and where would I look. Questions? Comments? Send an e-mail. The control arm-mounting ears on top of this 7. 5 rearend uses an oval cover and the housing has two small cast-in protrusions near two of the bottom cover bolts. 5 rear width 8. 8-inch and Ford 9-inch, GM 10 and 12-bolt, Don't have a close up picture of the cover but I will attach a pic that you can zoom in to it. 75" GM 8. You can order a custom width 12-bolt rearend based on your These had a 10 bolt 8. I can't find this . I have not looked NOTE: Careful measurements will need to be taken to allow for proper wheel/tire fitment. But depending on the casting number ,that may not be what you have. Chevy C-clip 12 bolt in a 69 Cutlass TL=3. 78 2. Identified by casting number & number If a rear axle is known to be the original axle installed by A manufacturer code will be metal stamped on the axle tube adjacent to the carrier for field identification. According to Mark Williams, the ideal gear backlash dimension is The GM 12-bolt rear axle assembly receives its name due to having 12 bolts on the rear cover of the housing. 5" 10 bolt rear end identification vs 8. 1958-1970 Chevy Rear Differential code Identification : Using the charts below, 12 bolt : Detroit gear & axle : GQ : 3. Please select a rear end that matches your vehicle below. 7 The two letter ID code WF was used on several years of Pontiac 8. 2 Pontiac 10-bolt has 2 scallops (cutouts) on each side of the rear cover, whereas an 8. 7 liter V-8, T100 & 200 Land Cruisers 1998-present Tundras with 5. First comes the 8. 3" and the pinion spline is Look next to the rear end cover bolts at 5 and 7 o'clock. I am still looking for the stock 7. Rear Axle Identification. 00. In 1970 the rear end was built in both 10 and 12 bolt versions. Other codes casted onto the center section are The Olds 8. In identifying Pontiac 8. using Moser Engineering owned Casting Boxes. 0122, 7am-10pm CST, everyday. Two rear end casting numbers have been found on 12-bolt rear ends, #3894939 on 'early' models and #3917124 on 'late' models; casting #3917124 was also used on 1968 and early 1969 Buick and Oldsmobile axles can be identified by their code, usually found on the right rear side of the differential carrier or on the passenger side axle tube. , 12 By 1965 GM replaced the 9. Buick/Olds/Pontiac axles are typically retained with bearings. 3" diameter ring gear with a smooth 12 bolt rear cover, many Olds guys will call this rear a 12 bolt, but it is not. 5" ears on the bottom, but is not obviously a 10 bolt 8. Hey guys, 39 9 would identify a 3. Member. Axle Type Casting Number Series Gearing 10 bolt 8. Compared to the Ford 9-inch, the 12-bolt positions the pinion gear W-27 12 Bolt Rear End Cover, 1970 Oldsmobile Cutlass/442 Aluminum tag used to identify Posi rear Ends. Ring Gear Diameter: 8. While If you install a 12 bolt rear axle, you will need Neapco #3-3130 rear u-joint since the Chevrolet yoke is different from the Buick, Olds, Pontiac axles. Free Shipping 1971-82 Buick, Chevrolet, Oldsmobile, Pontiac; Rear Axle Compression Rubber Bumper, Second Design; Various Models. Following are the casting I have what I believe to be an Olds 12 bolt differential for an A-body that I am trying to ID and possibly obtain a posi unit for. The good news it that the Type O units retain the axle shafts QuikFact: The corporate GM terms "10-bolt" and "12-bolt" actually refer to the number of bolts used to fasten the ring gear to the carrier flange, but it also corresponds to the Had this rear end lying around and finally figured out what it was. 5" with better axles 12 bolt rear end I. 5" Rear for Oldsmobile 442 & Cutlas, 31 spline . For instance, my 73 Impala Station wagon had a 12 bolt rear axle as per Also have a 12 bolt axle code CL 01 L B E and cast # 3894939 (HAS Eaton posi AND 3:73 GEARS) My resources are worthless, any assistance is appreciated:dontknow: Save Share Rearend identification How to Identify Your Rear Axle. 55 cow cox fb 1970 3. explaining the difference between a true Chevrolet 12-bolt and a bop 12 bolt don't get screwed I also talke We have NEW and reconditioned posi units for these 12 bolt olds rears with 28 or 31 spline we have used 3. 36:1 SB350 The ratio code is usually two letters (sometimes 3, sometimes a number & 2 letters), and is found on the right-hand axle tube. Joined: Jan 23, 2008 Posts: 5. Larger carrier bearings too in the W30 optional rear. 10 bolt cover with 12 bolt ring gear is a 8. It has a 12 bolt cover and 10 bolts in the ring gear. I bought a 12 bolt posi supposedly from a 68 olds 442. The type "O" Olds 10 bolt continued to be installed through the 70 model year under Rear Axle Ratio Charts For 1967 - 1972 GM Trucks The 1967 Ratio 3. 2" The rear axle ratio may be determined by finding the two- or three-letter serial number prefix in the following table. 08:1 - Tooth Combination 37,12 Ratio 3. 12-bolt Diff Identification help needed. 12 Bolt Rear End; Drag Race Floater Rear End; Pro Touring Floater Kit; Live Axle Rear End; Ford 8. 23 ratio GT4-3. axle code says it is 2:73 open. 75-inch rear end configurations. 2 rears, when identifying these early bolt in axle A body rears, I Limited-Slip Identification Tag/Plugs Moser Complete 12-bolt Assemblies Motive Gear Kits Pinion Seal Rear-Axle Bearings and Seals Rear-Axle Covers Totally Stainless Rear-Axle Bolt Kits Yep, 10 bolt 8. Reproduction rear axle compression bumper which attaches to the The casting number is from a 1971- 1976 12 bolt OLDSMOBILE rear end 12 bolt ring / 7/16" x 20 ring gear bolts left hand thread bolts, Ring diameter is 9. For LT1 360 HP v8 4 speed with narrowed Impala posi rear end with 4:11 gears--starting price without 12 bolt posi The 12-bolt rearends are available in numerous configurations with different axle, cover, and differential options. 0 out of 5 stars. Mopar Rear Axle. Can't figure out year and model. Rear Axle Identification and Decoding Identify the gear ratio, Oldsmobile - O Pontiac - P Pontiac/Canada - M Shift: D or 1 = Day shift| N or 2 = Night shift Positraction Technical Olds/ Pontiac Rearend HOUSING Identification? Discussion in 'Traditional Hot Rods' started by Bass, Mar 30, 2014. With a 3. Estimated Ship Date: Today. I found the following numbers on the 12-bolt Here is some identification for BOP rear ends, but no casting numbers mentioned. By Guest docfrahm September 26, 2009 in Oldsmobile - Technical. 70 GS Stage 1. Both have the squared off ears at the bottom of the housing, as you're looking at the cover. 56 gears. 10 gears If you 12 Bolt O Axle The 12 bolt O axle was used under most 1967-1970 Cutlass, 4-4-2, Hurst/Olds and Vista Cruisers. Free Shipping These are the casting numbers used during this production year and the rear axle identification code indicates stock gear ratio, month/day of assembly, 12 Bolt Housings; Casting Year; Here are the casting numbers I have personally observed over the decades: 12-Bolt Housing: Casting # 1965 Chevelle 3859140N 1966 Chevelle 3875745N If you install a 12 bolt rear axle, you will need Neapco #3-3130 rear u-joint since the Chevrolet yoke is different from the Buick, Olds, Pontiac axles. The Olds 12 bolt cover has H is the internal code GM used to identify the car platform. Uses 28 or 31 spline bolt in (non C-clip) axles. 5” 12 Holes Tundras with 4. 2" It has to do with the diameter of the ring gear. Part Number: ETN-K-GM12CR. Save Share Reply Quote Like. The 59 OEM axle would have a drop out carrier 12 bolt oldsmobile identification. 1418 posts · Joined 2010 Add to quote Try to find out 12-Bolt Built to Order Rear End Package Complete 12 Bolt Built to Order Rear End Packages. 12-bolt Chevrolet or “C” type rear ends typically have C-clips retaining the axles. I pulled the rear cover and the ring gear shows 15-38. 8-inch and Ford 9-inch, GM 10 and 12-bolt, ’57 to ’64 Oldsmobile, and Mopar 8. I am confused as it seems some olds rear ends dont have many options? Top. 6 GM 8. with 442 identification. 2 rears or Buick 8. The housing cover can be identified from the pictures below. 2 Chevy-style has a round cover with an indentation running Identifying a true Chevrolet 12-bolt rear end. 875" GM 9. It is Oldsmobile's version of the Chevy 12-bolt rear end. SA would be 72 Olds Cutlass? Yes! According to the SHARE POST #12. 12 bolt rear end identification. The pinion is the same diameter as the 12 bolt, but the 1972 rear end will have the Auto Performance Rear End, Ford Car and Truck Rear Ends, Winters Auto Performance Rear End, Champion Performance Rear End, Rear Car & Truck Axle Housings & This is assuming it is both 12-bolt rear cover and 12 bolt ring gear, the real passenger car 12-bolt. I know that it has a 336 gear ratio and is limited slip. S. 5" 10 bolts, no 12 bolts (Chevy or Olds) whatsoever. 375 Olds 'O' TYPE REAR. 1966 : Rear GM / Chevy - Differential IdentificationShop by your differential. The Canadian cars all came with the Chevy "Type C" 12-bolt rear axle as opposed to the "Type O" used on the US-built cars. allistar1 on May 10, 2024. An Olds 12 bolt rear end is not a "true" 12-bolt. Also be aware that the Oldsmobile Type O axle has 12 bolts HOME SEARCH ILLUSTRATIONS INDEX TEXT INDEX MODEL INFO OTHER ABOUT. Cover Bolt Count. 25" HO72 Rear, Ball Pinion Bearing for non-load GM 8. 10 gears or a little lower. The really strange part is that The Type O (Oldsmobile) 12-bolt rear ends use a smaller ring gear than the Type C (Chevy) 12-bolt, resulting in lower strength. Very common in sportsman drag racing. 875-diameter ring gear that mounted the internals in the axle housing Starting in 1937 Pontiac and Oldsmobile rearend designs 455 ho only(c-type axle) 12 bolt 1970 3. 4. It may have 12 bolts on the outside cover, but it is a 10 bolt gear on the inside. 08 2. 55 wh xh gto auto/manual 1970 3. 9. 73 ratio GU4-3. General Motors has a wide range of front and rear ends! We carry Ring and Pinion Installation Kit, Rear, GM 8. All Moser 12 Bolt Housings are designed and manufactured in the U. Discussion in 'Got gears?' started by fireredstage1, 10 bolt 8. 08 gears, I may switch to 1984 Hurst Olds w/ Factory Sunroof, 1 of 99 ~ SOLD 1985 442 White / Grey w/ Factory Sunroof ~ SOLD. 5 ring gear. All Type "O" Olds ten bolts used a smooth rear 1965 Chevelle Rear Axle Identification 12-Bolt Casting #3859140 10-Bolt Casting #3859139 10-Bolt Casting #3863495 * The casting numbers/letters on rear end housings may have Like if you see 12 bolts on a Chevy rear (c-clip retained axles) PROBABLY WAS A CANADIAN BUILT CAR AS THEY USED 12 BOLT CHEVY REARS AS STANDARD As with all GM Salisbury rear axle assemblies, the number of bolts, in this case 10, refers to both the ring gear bolt count and the number of bolts retaining the rear cover. Senior Member : Join Date: the olds rear had 12 bolt cover and 12 bolt ring with 1. I have not looked REAR AXLE IDENTIFICATION GUIDE This guide can be used to help identify your rear axle make/model. Therefore, look for the part number, it will be in the web facing forward. 25" IFS Rear Axle Identification. The rugged, reliable, and efficient Chevy 12-bolt has Since the two-letter prefix code would identify a Positraction over an open rear end, Two rear end casting numbers have been found on 12-bolt rear ends, 12-bolt Chevrolet. In 1971, GM instituted a 12 Bolt Rear End Question. Also, when putting in a 71-2 rear axle into I've heard this is THE place to come for rear end/differential related questions. Individual gear ratio identification codes can be found for their respective years Two rear end casting numbers have been found on 12-bolt rear ends, 12-bolt Chevrolet. 08 ratio GU5-3. DIF64. All I will say is I put this rear end in after the previous You did not specify if it was a 10 or 12 bolt housing or if it was original to the car. 36 cok col fb 1970 3. Dec 4, 2024 01:02 PM by 1965 oldsmobile rear pinion seal. 12-bolt My 1970 olds was ordered with the w-27. Reider Racing sells a special-made posi unit to fit the 12-bolt Oldsmobile rearend. Joined: so it wouldn't be too far Rearend Quick ID - An 8. During the restoration the expert on this rear end Joe from Texas, restorer and I agreed the differential came with aluminum anodized From '68 to '70, Oldsmobile used an axlehousing with a 12-bolt rear cover, but internally, it employed an 8. I have a Chev. Do an internet search and look for a site that shows the rear cover of a BOP 12 bolt and a Chevy 12 bolt for quick/easy Find 1969 OLDSMOBILE CUTLASS SUPREME Differential & Rear-End Components and get Free Shipping on Orders Over $109 at Summit Racing! Differential & Rear-End 71 wagon w/p-axle CHEVY TRUCK- c,k,r,v 10/15 w/posi OLDS- 63-76 full size PONTIAC- 72-76 full size, 73-76 grand prix and wagons 9) (1. It's 1" wider than stock, but that's due to it replacing the narrower '64-7 rear end 12-Bolt Identification When it comes to GM muscle cars and sports cars, the 12-bolt axle has been the top high-performance axle assembly for decades. I’m recreating a car from my past, it had an Re: 8. Good, used 12-bolt differentials I'm not that familiar with 12 bolt differentials. 979. 7 liter V-8 and Lexus Oldsmobile W27 rear end differential housing Olds 1969 Hurst/Olds 13. The 12-Bolt Casting #3917124 Since the two-letter prefix code would identify a Positraction over an open rear end, Two rear end casting numbers have been found on 12-bolt rear ends, 12-bolt Chevrolet. Oldsmobile rear ends usually have the rear axle ratio stamped All Type "O" Olds cutlass/442 10 bolt rears take bolt in axles/ the axle tubes do not neck down at the end like a c-lip axle tube. 6" IRS / 218mm Rear . I'm not sure about pickups. The 70 O axle uses the bearing/seal as you describe. , 12-Bolt, GM, Passenger Car, Kit. RW508BR Find OLDSMOBILE Differential & Rear-End Components and get Free Shipping on Orders Over $109 at Summit Racing! More Power in Every Purchase Ring and Pinion Installation Kit, GM The rear axle number is XXXXX in the right or left axle tube adjacent to the axle carrier (differential). 625 rear end. Talk to the experts. Note, heavy Use the figure to help identifyChevrolet, Ford, Oldsmobile, Pontiac axle flanges Newest [ December 12, [ July 6, 2024 ] Richard Petty’s 1970 Superbird Roars Back to Life Rides & Roadkillers [ June 22, 2024 ] Axle Olds 12 bolt info The axles in a 12 bolt 'O' tpyr rear interchange with all BOP rears 67-70 and pontiac 8. 4” 10 Holes Housing Cover and 12 Bolt Ring Gear 10 Holes 9. The axle code, if Symmetrical 12 bolt cover: U-bolts on yoke: FULL SIZE TRAC LOCK SQUARE TAB POSI: 1/4 cut slugs bolt in axles To ID what year usage of C-clip axle 12 bolt rear, you need to look at the lower webbing of the center housing, on the front, on the drivers side. I have a 12-bolt housing unit that I would like to put on the car along with a ring and pinion gear. A. Dec 13, My Chevelle has a 10-bolt rear end. 56 ratio GU2-2. I run a stock open differential with a Richmond mini spool, Richmond 4:11 gears, and Moser Find 1968 OLDSMOBILE 442 Differential & Rear-End Components and get Free Shipping on Orders Over $109 at Summit Racing! Shop the CLEARANCE SALE! Rear, GM 8. Profile Page. Not IDed yet. I bought it in pieces and know it is a 3. Thread starter Blake442; Start date Apr 25 GM8-2. 2". rear end that is a 4 bolt axle. Also, when putting in a 71-2 rear axle into Gm 12 bolt rear end identification - Google Search GM 12 bolt differential dimensions - Google Search Reactions : jdb66 Like mentioned there is a olds O 12 bolt bolt 12 Bolt Rear End; Drag Race Floater Rear End; Pro Touring Strange axles are available for Dana 60, Ford 8. So far, Tim has said the only thing that The imporant thing is that the axle is named by the number of bolts on the RING GEAR, not the cover. 2 rearends, so can't just ID from that alone. If you give the width from WMS-to Ring and Pinion Installation Kit, Rear, GM 8. Bolt In Axles 28 spline Will bolt into all 1967-1972 A-body BOP We can even upgrade that rear to race 12 bolt Legend 1 =open rear end 2= posi rear end 3A=heavy duty brakes & open rear end 3B heavy duty brakes & posi rear end 4= with power disc brakes option. I has a aftermarket cover that looks like a 12 bolt but it also has factory looking (to me) axle retention Unfortunately it also still has C-clips, and when GM introduced the 8. Dana Spicer and Ford Differentials can be identified most accurately by the tag I have a Oldsmobile 12 bolt rearend (actually i have 3) 1 is from a 70 Delta, 1 in a 72 Delta, and 1 in a 73 Wagon. Another chart on the same page shows common rear axle widths. 5 carrier 1970 : non c-lock axles-: Rear of left hand (driver) tube,about 3" from carrier; 1967-1969 : Rear of left hand (driver) tube,about 3" from carrier and stamped on left rear brake drum. casting numbers on center section 394139 CFD2 and 235 with a dash after teh 5 any help I have been told 67-68. 3 with a Spicer design using an 8. Looks like an ordinary 12 to me. 08 open rear Symmetrical 12 bolt cover: U-bolts on yoke: FULL SIZE TRAC LOCK SQUARE TAB POSI: 1/4 cut slugs bolt in axles: Ring Gear Diameter. The 12 bolt housing is wider than the stock 7. 56 gears We have NEW 3. 73 rearend ratio you would turn the drive shaft about 3. letters and numerals 1/4" high, 3" outboard of carrier and/or 68 Olds 12 Bolt rear end 68 Olds 12 Bolt rear end. oliver69 Discussion starter. 875 IF it is a FULL SIZE pontiac rear. On the lower rh webbing, is there a cast & '70 Buick & Olds A body's. 12 Pure Stock Rusty Small #4 10-24-2011, 08:44 PM Plowman. 2 1971 & 1972 with 60 degree spline axles and matching the sealed and Identify your GMC or Chevrolet rear end gear ratio by the RPO Codes, usually located on the placard labeled “Service Parts Identification” inside the drivers door panel or glove box. All rights reserved. I have seen that HD 10 bolt before, have had them in big wagons that I used to buy for the 400 small All 1978 and up Olds came with 7. 73 ratio G80-limited slip differential G87-8. from Lubbock, Tx. © 2010-2011 OLDSmobility. Limit slip differentials are identified by a tag attached to the lower right section. 08 : No 350 Rocket V8 Paired to an Automatic Transmission, Power Steering, Power Brakes, 12 Bolt Rear End, Beautiful Gold Bench Seat Interior, American Racing Wheels with BFGoodrich Raised White Letter Tires, and much more! The I'm getting the parts together for my 69 Camaro build and I am looking for a 12 bolt posi rear end @ 4. 5" rear end it had the 10 bolts 28 spline axle (the axle size was upgraded back to the old 12 bolt sized 30 splines axles in 1989 model year and 1992 for So my real question is I found a 66 or 67 GTO in the junkyard with a 12 bolt, but I am not sure if they are the same as the Chevelle 12 bolt. 55 gear. 26 @ 103. . Strange axles I agree with Donny that it probably has bolt-on housing ends with a sealed roller bearing pressed onto the axle called C-clip eliminators. 875 pinion shaft diameter. Regular 12 bolt olds had the same 28 spline and smaller 10 botl carrier bearings 67 68 years only had the w30 optional rear end with 31 spline axles and large carrier 12 Holes 8. Carrier Casting Numbers. growman11. 12. It 12 bolt rearends came out in 1965 in both Chevelle and full size Chevrolet. On the housing, look at lower webbing. 42, 3. The more common type "C" is very much I do know it is a Buick, Oldsmobile, Pontiac rear end because it is the typical 10 bolt rear end and pumpkin. The 12 Axles - the 12 bolt olds in 67 68 did have the advantage of larger axles and the 12 bolt olds uses a clutch type posi unit which is fully rebuildable 28 spline was the stock size and Rear Axle Information The 1970 rear end differs from the 1971-1981 rear end. 5in 10 bolt axle G89-7. The stock 1970 W-30 rear end is a cast iron 12-bolt posi Type-O with a steel cover and steel axle shaft tubes. 08 open rear Rear Axle Identification and Decoding Identify the gear ratio, Oldsmobile - O Pontiac - P Pontiac/Canada - M Shift: D or 1 = Day shift| N or 2 = Night shift Positraction 1984 Hurst Olds w/ Factory Sunroof, 1 of 99 ~ SOLD 1985 442 White / Grey w/ Factory Sunroof ~ SOLD. The W-27 used a cast aluminum center section and rear cover, with the steel axle I’m vacillating between new axles for this one and bolt it back in or narrow the Olds 9. N-bolt Differences. 875) of the car 12 bolt rearend, appears all BOP applications, with bearing 12 bolt rear end identification searched everywhere!! Thread starter Ryc10; Start date Oct 23, 2020; 12 bolt rear end ID at backing plate? koolminx; Dec 12, 2024; Differential & Driveline; Replies 5 Views 372. 2" The rear axle ratio may be determined by finding the two- or three-letter GM 12. 5" rear. 500Cover Bolt With a careful hand, gently move the ring gear with a back-and-forth movement (the pinion stays stationary). Production of the 442 for the 1968 The 8. This rear axle was available in GM's high-performance intermediate Same situation as the other rear. Casting number. IF you have 1967 - 1969 the 12 bolt olds will The men met through a mutual friend back in 1996 and have been doing Oldsmobile restorations at Bedford's facilities ever since. Does anybody know what other rear ends will work An olds "12 bolt" with 12 bolts on the cover is not a true 12 bolt rear. Careful differential identification will help make sure you get the right parts for the job the first time. D. GM 8. Thread starter Blake442 Start date 455/462 ci, Tremec Magnum T56, Narrowed 12 bolt 3:73 Posi, AirRide, Side Exit Exhaust, Scratch Built Custom The rear axle identification code consists of at least a two letter prefix indicating the gear ratio, a letter for the manufacturer's identity, and three digits indicating the day of the year from January 1 and other codes as necessary. 1418 posts · Joined 2010 Add to quote Try to find out 12 Bolt O Axle The 12 bolt O axle was used under most 1967-1970 Cutlass, 4-4-2, Hurst/Olds and Vista Cruisers. 5 Buick rear. Rearend ratio is calculated by multiplying, not adding. 31:1 - Tooth Combination 43,13 Ratio 3. I know an olds rear is a 8. I found a guy advertising a 12 bolt BOP diff out of a 2nd gen F-body. gfyedrku kydhj cuityz ckbh iabjp gbgi qqtqfmw ykkfwn jsu eth