8 3/4 help

[65DODGE]

i just gotta say i'm stumped here changing out my 741 case in my 65 coronet to a 489 sure grip unit i bought and i put the new gasket up to the housing and the 2 bottom studs on the housing dont line up with the 2 holes in the gasket so i take the gasket over to the 489 case just to see if maybe the gasket was boxed wrong nope all the holes in the gasket line up with the ones in the 489 case i thought you could put any case# in any 8 3/4 housing mine is the original housing or so i think you never no but it does have a bulid date of 8/64 which is in the same time frame as the build date of the car my question here is what is going on here do i need to change out to a later year housing mine does have the axle adjuster on the pass side any ideas anyone?thanks.

 

[65DODGE]

sorry nevermind looking into it further it seems that i have a 8 1/4 being it was an early built car they put a left over 64 rear in it shouldnt 65s all have 8 3/4 s the info i have found is that 63 and 64s 8 1/4 s used a 741 case and it visibly looks like a 8 3/4 but the bolt pattern on the housing is different i will have to change the housing to be able to use my 489 case.

 

[YY1]

At least you have the expensive part

The axle housing is the cheap part.

 

[72 Charger SE]

sorry nevermind looking into it further it seems that i have a 8 1/4 being it was an early built car they put a left over 64 rear in it shouldnt 65s all have 8 3/4 s the info i have found is that 63 and 64s 8 1/4 s used a 741 case and it visibly looks like a 8 3/4 but the bolt pattern on the housing is different i will have to change the housing to be able to use my 489 case.

8 1/4 inch rear ends look nothing like 8 3/4 inch rear ends. 8 1/4 has a 10 bolt rear differential cover (facing rear of the car.) 8 3/4 has no removeable rear differential cover, and the gears are removed through the front of the housing as one assembly.

Post some photos of what you have, I'm sure someone on here can identify it for you and help you figure out what the problem is.

 

[65DODGE]

8 1/4 inch rear ends look nothing like 8 3/4 inch rear ends. 8 1/4 has a 10 bolt rear differential cover (facing rear of the car.) 8 3/4 has no removeable rear differential cover, and the gears are removed through the front of the housing as one assembly.

Post some photos of what you have, I'm sure someone on here can identify it for you and help you figure out what the problem is.

this does not have a removable housing cover it looks identical to a 8 3/4 they made a 8 1/4 in 63 and 64 the only difference i can see is the 2 bottom mounting studs are located different the 63 and 64 8 1/4 used a front load carrier with a number of 741 you can see how i fogured i had an 8 3/4.mine was an early build car so i can only assume they used a left over 8 1/4 in my car to use up the left over 64 model year parts this 8 1/4 can not be confused with the later 8 1/4s no rear diff cover i found this info on the net under a 8 3/4 rear axle guide from hemmings.

 

[72 Charger SE]

Can you post a link to your source? I'm not doubting you, since I know manufacturers did some strange things from time to time back then. I'd really like to read it. I've never heard of this rear axle before.

According to the MP Chassis book, the 8 3/4 inch was the only banjo-style (gears drop out the front) rear axle they ever used from 1960 on. Could be they put something older and left over in your car, or maybe someone else swapped an older rear axle into the car.

The full casting number for the 8 3/4 inch 741 case should be 2070741. Is yours different?

 

[65DODGE]

Can you post a link to your source? I'm not doubting you, since I know manufacturers did some strange things from time to time back then. I'd really like to read it. I've never heard of this rear axle before.

According to the MP Chassis book, the 8 3/4 inch was the only banjo-style (gears drop out the front) rear axle they ever used from 1960 on. Could be they put something older and left over in your car, or maybe someone else swapped an older rear axle into the car.

The full casting number for the 8 3/4 inch 741 case should be 2070741. Is yours different?

sorry im an idiot went out and looked at everything again got a new gasket every thing lines up fine its a 8 3/4 must not of had gasket positioned on the housing right it seems i turned it around every which way but it was late and i was about burned out for the day im glad all needed to to do was take another look at it but the info i found about the 63 64 8 1/4 i googled 8 3/4 housing identification and i believe it was a hemmings article if you read the article it lists a 8 1/4 looking like a 8 3/4 and takes a 741 case but the mounting flange bolt pattern is different than an 8 3/4 and was primarily built for 6 cyl applications light duty so there still is a mystery out there about that rear i guess thanks to all sorry false alarm.

 

[72 Charger SE]

I couldn't find your article on Hemmings. I'm glad you got your problem solved though.

 

[wingcarenvy]

Here are some pics for reference. Someone could have put an 8.25 in your car, but NO B body prior to 65 came with one. All 8.75s have interchangeable third members (the gear set and its housing). The gasket and third member only go in one way so its easy to get the gasket mixed up and it wont line up. These first 3 pics are of the 8.75 in my Roadrunner. The last shot is kinda crappy one in that it barely shows the removable thrid member. The link below is a shot of an 8.25.

http://img196.imageshack.us/i/dsc03433wa.jpg/

 

[Cranky]

The two top studs on the 8 3/4 have a different spacing than the rest of the studs so the gasket only goes on one way.....