1970 rear wheel cylinder

[mtull]

Can anyone confirm part number and casting number for rear wheel cylinders?

I have an Sept 1969 built 1970 Challenger with disc brakes. If I understand the parts manual correctly, the part number for the rear brake wheel cylinders is: 3420997?  I found other forum posts stating the casting number is: 3461776?  I've also found information suggesting other part numbers.  Perhaps the contradictory information is due to early vs. late production cars?

Thank you,
Mike

[MoparLeo]

We have parts catalog downloads in the Resource section. You may find the parts numbers there.

[mtull]

We have parts catalog downloads in the Resource section. You may find the parts numbers there.

Thank you for the suggestion.  The parts manual states the part number is: 3420997.  I've found a few restoration threads stating the casting number for said part is 3461776 however a reputable source states the number is 3164776 (hopefully a typo)?  Additionally, I talked to a forum member with an early built E Body that has rear wheel cylinders with casting: 2881613.

Some forum threads suggest the cut-off and begin-dates for part numbers wasn't always an exact date but rather supply driven thus, some early cars have been found with previous year part numbers.

With that said,  I was hoping our fellow forum members may be able to provide more info on the wheel cylinder casting numbers found on early vs. later 70 E Body?  Could it be either (3164776, 2881613) depending on the build date?

 

[MoparLeo]

Another reason that part numbers don't always "go by the book" Is the the car manufacturers used multiple vendors on some items and that can be another reason for different casting numbers vs part numbers.

[mtull]

I believe I found the answer I was looking for.  Although my sample size is very small (3 cars). It appears some 1970 Challengers did come with rear wheel cylinders with casting number 2881613.

As an example, go to image 214 of 285, then scan down to the middle of page and notice comments on 'Brake Hardware'  https://bringatrailer.com/listing/1970-dodge-challenger-r-t-hemi/?fbclid=IwAR1bNuqIZ98M0PlSNTJ6dFafUN7GOi-VkYXCtklu1gTEl6Ay9fkS8pox07o

The car referenced above was ordered November of 1969 and delivered August 1970.  The aforementioned dates are well after two other cars in my sample set were delivered but the car still received the  2881613 wheel cylinders.

[JH27N0B]

I should take a rear wheel and drum off my November built Challenger and look.  But I'm already overloaded with fall chores I'm trying to motivate myself to do. But someday I will.
In the case of master cylinders and wheel cylinders, there was only one vendor to Chrysler then, and it was Bendix.  So it wouldn't be a case of different numbers on same model cars from different vendors.
Though one thing I've wondered about for a long time that I don't think I'll ever find an answer to, and that is with the drum brake master cylinders used on most '67 through '70 Mopars. I've seen 2 different casting numbers and one letter sequence (AANF) on OE Bendix samples, with no apparent differences in them other than the casting number between the three.
Why was that I wonder.  Bendix did have two manufacturing plants for these products I believe, many master cylinders were made in Canada, but also in South Bend.  Being so widely used, they must have made millions of these drum brake MCs.  Were they made at 2 plants and they used a different casting number casting at each plant?  I'm not sure why they would, but it's possible.
Otherwise I don't even have an educated guess on this question.
One other thing I've seen is substitutions.  Plants sometimes run into shortages of a part and engineering approved a similar part to be substituted to keep the line going building product.
So a car might have a "wrong" part on it that actually was on it when it rolled off the line.  But how can one prove that now?
I bought my T/A in 1978, and it had a 3 speed wiper motor on it that had the correct part number for E body 3 speed wiper motors, but it was a yellow sticker.  Under the sticker was a different number stamped into the barrel.
I've seen that same yellow sticker on a few other cars including some unrestored cars like Tony's F8 Challenger convertible.  Was there a shortage of wiper motors for a time, and they put stickers on some similar ones that could be substituted to keep the line stocked?  Did a bunch of barrels come in stamped with the wrong part number and the supplier put stickers with the correct part number on them to avoid scrapping components?
Fact is, it's doubtful we will ever know.  When I restored the car I had a correct date code core restored to use and the one with the sticker got traded in as a core.
Unless you have owned a car since it was new, and never changed any parts on it, you can never prove what was originally installed on it. Even that doesn't necessarily prove anything.  Sometimes cars were found to have a problem or two during new car prep, and parts were replaced by the service department before the car got sold!

[mtull]

JH27N0B,
Thank you for the education on several points.  Very interesting and very much appreciated expertise.

Thank you