76 breaks problem

[slant6dart76]

I have a '76 4 door with the slant 6. Discs on the front and 10" drums with 1 3/4 shows on the back. I have read some threads about the centric 123.63044 being the right replacement drum. I ordered 2 from rockauto, website said 10" 1 3/4 but received 12".(returned) Went to ebay right part number but also received 12" drums. Any suggestions? Mechanic says its supposed to have 10" 2.5 shoes.
I cant seem to find 10" 1 3/4 drums anywhere. Should I look into swapping the backing plate to take the 10" 2.5 that "its supposed to have"?
Thanks guys

 

[townsend]

The 1976 Chrysler part number is 4049663.
Many of these can be found on eBay.

 

[Dana67Dart]

This part number is specked for 66 thru 70 something 10x1.75, 7 1/4 and 8 3/4 rears.

At some point the 8 1/4 with 5x4.5 became the 8 3/4 replacement

Iirc the 7 1/4 was still used in /6 cars.


What rear end do you have?

It looks like 5x4.5?

Post some photos


I got these from summit. Great customer service.

The first set they sent me had 9" Oriley brand drums inside.

2 possible things happened...

1. The manufacturer mis labeled the box
2. The manufacturer put the wrong drums in the box
3. A customer bought the cheaper 9" drums at O'riley and the more expensive 10 inch at Summit. Swapped the 9" into the 10" box and returned to Summit who resold them not knowing they were the wrong part inside.

Photos just taken from my spare set.

 

[Dana67Dart]

123.63044 being the right replacement drum. I ordered 2 from rockauto, website said 10" 1 3/4 but received 12".(returned) Went to ebay right part number but also received 12" drums

Where are you measuring the 12"?

 

[Professor Fate]

Couple of problems here.
The Centric 12363044 is a small bolt pattern, 10" x 1.75" drum (brake diameter is measured on the inside of the drum by the way. If you look at the specs for that part number, the outside diameter is listed as 11.610", which is where I assume you got your 12" measurement). These drums are used (again, re-read the application info) on the rear of vehicles that have front drum brakes, which gives them a 4" bolt circle and 10x1.75 rear brakes.
YOUR car has front disc brakes, which means you have a 4.5" bolt circle and gives you the 10"x2.5" rear drums; Centric 12363020.
You got the brakes that you ordered, you just didn't read RA's description closely enough and ordered for the wrong brake option.

 

[slant6dart76]

This part number is specked for 66 thru 70 something 10x1.75, 7 1/4 and 8 3/4 rears.

At some point the 8 1/4 with 5x4.5 became the 8 3/4 replacement

Iirc the 7 1/4 was still used in /6 cars.


What rear end do you have?

It looks like 5x4.5?

Post some photos


I got these from summit. Great customer service.

The first set they sent me had 9" Oriley brand drums inside.

2 possible things happened...

1. The manufacturer mis labeled the box
2. The manufacturer put the wrong drums in the box
3. A customer bought the cheaper 9" drums at O'riley and the more expensive 10 inch at Summit. Swapped the 9" into the 10" box and returned to Summit who resold them not knowing they were the wrong part inside.

Photos just taken from my spare set.


View attachment 1716218851

So these is the 3rd pair I ordered thinking one of the things you mentioned happened and I keep receiving these12" drums.
For the rear end I'm not sure which one I have. I posted a picture of how the 10" shoes look inside the 12" drum I received.

 

[Professor Fate]

So these is the 3rd pair I ordered thinking one of the things you mentioned happened and I keep receiving these12" drums.
For the rear end I'm not sure which one I have. I posted a picture of how the 10" shoes look inside the 12" drum I received.

View attachment 1716218888

View attachment 1716218889

View attachment 1716218891

View attachment 1716218894

Um, those are 6 bolt drums you've got there. Lord knows what they're actually for, but it ain't a Mopar.

 

[slant6dart76]

Um, those are 6 bolt drums you've got there. Lord knows what they're actually for, but it ain't a Mopar.

Seems like no matter where I order them from I get those 12".

 

[Professor Fate]

Have they all been 6 bolt? Sounds like a massive mis-packaging error at Centric.

 

[slant6dart76]

Couple of problems here.
The Centric 12363044 is a small bolt pattern, 10" x 1.75" drum (brake diameter is measured on the inside of the drum by the way. If you look at the specs for that part number, the outside diameter is listed as 11.610", which is where I assume you got your 12" measurement). These drums are used (again, re-read the application info) on the rear of vehicles that have front drum brakes, which gives them a 4" bolt circle and 10x1.75 rear brakes.
YOUR car has front disc brakes, which means you have a 4.5" bolt circle and gives you the 10"x2.5" rear drums; Centric 12363020.
You got the brakes that you ordered, you just didn't read RA's description closely enough and ordered for the wrong brake option.

If you look at the pictures I uploaded I did not receive the 10" 1 3/4 drums.
My car has the 4" bolt with 10" drum and 1 3/4 shoes. I've been told it should have the 2.5" you mentioned but it doesn't. I'm not sure why.

 

[Professor Fate]

In '76, factory front disc brakes were 5x4.5 bolt pattern. The factory did not mix'n'match different bolt patterns on the same vehicle, front to rear. With front disc brakes, the only way you could have 5x4 in the rear is if somebody swapped in a different differential. But, I see you have the same wheels all the way around on your car. So if all your wheels (and therefore the bolt circle) are the same, then you either have non-'76 front disc brakes (either '72 and earlier Kelsey/Hayes, or aftermarket), or you are measuring your bolt circle incorrectly and have a 4.5" bolt circle. Look at @Dana67Dart 's picture above, and how he is measuring the bolt circle- the outside of a stud/hole to the center of a stud/ hole across from it; his picture shows he is measuring a 4" bolt circle drum, and not a 4.5". Are you SURE this is what you have, and how you arrived at it? Both patterns were available in '76, but not together. 4 wheel drum cars got 4", cars with factory front discs got 4.5".

 

[Dana67Dart]

So these is the 3rd pair I ordered thinking one of the things you mentioned happened and I keep receiving these12" drums.
For the rear end I'm not sure which one I have. I posted a picture of how the 10" shoes look inside the 12" drum I received

I think centric is having problems.

Take a photo of your rear end from behind. So we can see the rear cover.


Also measure your studs as described

Outside of one to center of opposite.

What is the OD of your studs.

They look 1/2"

And your center hole looks closer to 3" than 2"

Get all those measurements.

And report back

BTW 7 1/4 and 8 1/4 only use 4 bolts to bolt the backing plate to the housing.


8 3/4 uses 5


There is a possibility that someone put 10x1 3/4 shoes on a 10x2.5 backing plate.

Additional inconsistent info.

The brake hardware suggests pre 69, no spring in the auto adjuster

 

[junkyardhero]

something is certainly afoot. obviously getting a 12" 6 bolt drum when that's not only wrong for the application but wrong in the box is a whole issue.

i'd start with 100% confirming what you have cooking. a lot can change in 50 years. verify your rear end, bolt pattern spacing and diameter of the studs, and the same on the front. if you're not sure pics help and the train spotters here can id damn near anything.

the centering hub for the axle looks oddly tall to me, but maybe that's just how 7.25's are

 

[townsend]

Bendix catalog shows PDR0182 fits 10 x 2.50 rear drums.
Raybestos catalog shows 2947R fits 10 x 2.50 rear drums.
Both are available from multiple sources: Amazon, Summit, and many other vendors.

 

[cosgig]

Those look like 1 3/4” shoes, but since you have disc up front, you should have a LBP 7 1/4” rear, and that would use the more common 10x2.5” brakes. Looks like you have a mismatch there.

 

[H22A4]

Those look like 1 3/4” shoes, but since you have disc up front, you should have a LBP 7 1/4” rear, and that would use the more common 10x2.5” brakes. Looks like you have a mismatch there.

That’s the ‘fun’ in working on a older car. Even if it’s been in one family for a long time, unless whoever has the car now was left with a stack of receipts or was almost beside the previous owner/family member when parts were being replaced or upgraded, it’s a crap shoot wondering what the part number is that needs to be replaced.

I’ve got a folder of receipts that goes back to the late 80’s when my brother and I inherited the car from our grandmother. Yeah my grandmother didn’t save service receipts from when she owned the car but gas station she got the work done at was only doing regular work on it. Besides it’s only had 27k miles on it by the time my brother and I started driving it. At least she saved bill of sale from when she bought it new!

 

[slant6dart76]

I think centric is having problems.

Take a photo of your rear end from behind. So we can see the rear cover.


Also measure your studs as described

Outside of one to center of opposite.

What is the OD of your studs.

They look 1/2"

And your center hole looks closer to 3" than 2"

Get all those measurements.

And report back

BTW 7 1/4 and 8 1/4 only use 4 bolts to bolt the backing plate to the housing.


8 3/4 uses 5

That’s the ‘fun’ in working on a older car. Even if it’s been in one family for a long time, unless whoever has the car now was left with a stack of receipts or was almost beside the previous owner/family member when parts were being replaced or upgraded, it’s a crap shoot wondering what the part number is that needs to be replaced.

I’ve got a folder of receipts that goes back to the late 80’s when my brother and I inherited the car from our grandmother. Yeah my grandmother didn’t save service receipts from when she owned the car but gas station she got the work done at was only doing regular work on it. Besides it’s only had 27k miles on it by the time my brother and I started driving it. At least she saved bill of sale from when she bought it new!

Those look like 1 3/4” shoes, but since you have disc up front, you should have a LBP 7 1/4” rear, and that would use the more common 10x2.5” brakes. Looks like you have a mismatch there.

I can't post pictures and measurements as you guys mentioned at the moment because I'm out of town. As soon as I get back I will. Thank you all for your interest in helping me.

 

[Professor Fate]

Yup, late model disc brakes, '73-'76. 4 1/2" bolt circle. If all your wheels are the same (you can rotate your tires), you've got 4 1/2" in the rear, too.

 

[Bewy]

Could those be Imperial drums?

 

[junkyardhero]

Could those be Imperial drums?

to my knowledge, all ma mopar was 5 lug

obviously the big/HD trucks and modern stuff have their own jam.

maybe they're dakota 6 lug? what was that, 97?

 

[RustyRatRod]

Seems like no matter where I order them from I get those 12".

First, they are the wrong drums, obviously, but you need to learn how to measure them. You measure from inside to inside.

 

[Dana67Dart]

In a side note and I did this myself with every drum Summit sent me after the first two they sent were wrong...

Video tape in one continuous video you opening the outer shipping box and then opening the inner boxes showing part numbers and what's inside show all sides of the box to show that it is or is not opened etc.. That way you have proof that YOU are not the drum swapper

 

[BillGrissom]

Rockauto shows Centric 123.63020 for your car (1976 Dart, front disks). Their Centric listings are best since give all dimensions and photos.

Strange if your rear wheel bolt circles was 5x4"D. Does your spare wheel fit both front and rear? You can find many photos how to measure bolt circle. Show how you are doing it. Strange that you measure the OD of the drum, not the ID. Report back, don't leave readers hanging.

More Information for CENTRIC 12363020

 

[slant6dart76]

In a side note and I did this myself with every drum Summit sent me after the first two they sent were wrong...

Video tape in one continuous video you opening the outer shipping box and then opening the inner boxes showing part numbers and what's inside show all sides of the box to show that it is or is not opened etc.. That way you have proof that YOU are not the drum swapper

I will do this next time. Thanks for the advice

 

[slant6dart76]

Rockauto shows Centric 123.63020 for your car (1976 Dart, front disks). Their Centric listings are best since give all dimensions and photos.

Strange if your rear wheel bolt circles was 5x4"D. Does your spare wheel fit both front and rear? You can find many photos how to measure bolt circle. Show how you are doing it. Strange that you measure the OD of the drum, not the ID. Report back, don't leave readers hanging.

More Information for CENTRIC 12363020

I can try and order these. I will go check on the car monday ( its at the mechanic shop) and get the measurements I can to report to you guys. Thanks. I've been on vacation then sick, sorry for the delay.