Re: AAR/TA Rear Brake Drums??
[Re: floyd]
#1158568
01/16/12 03:40 PM
01/16/12 03:40 PM
|
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
xs29j8
master
|
master
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
|
Quote:
Is there anything special about AAR/TA rear drums? What siz are they supposed to be? Are they 11X2.5 or 11X3.0? Does any one have the part number or interchange numbers?
Thanks!
The rear drums are 11x2.5, I believe they are same as other 11x2.5 rear drums from 1970 models.
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: xs29j8]
#1158569
01/16/12 08:54 PM
01/16/12 08:54 PM
|
Joined: Jan 2003
Posts: 4,115
MD
floyd
OP
master
|
OP
master
Joined: Jan 2003
Posts: 4,115
MD
|
Thanks Allen - I had it in my head that they were 11X3.0. I'm still a bit confused on the 11x2.5 rear finned drums. I have a set of original 70-71 finned drums and the machined surface whre the shoe mates measures 2.75. I have an NOS set of 11x2.5 drums (part number 3549843) and the machined surface measures 2.5. I'm trying to figure out if the NOS ones will work for me.
Last edited by floyd; 01/16/12 08:55 PM.
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: Troy]
#1158572
01/16/12 11:58 PM
01/16/12 11:58 PM
|
Joined: Jan 2003
Posts: 27,471
So Cal
autoxcuda
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 27,471
So Cal
|
Quote:
...those are the original drums that came on my car, check out the pictures and you will see.
I would imagine that still had the original shoes in them too with only 30K miles???
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: Troy]
#1158573
01/17/12 12:26 AM
01/17/12 12:26 AM
|
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
xs29j8
master
|
master
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
|
Quote:
...those are the original drums that came on my car, check out the pictures and you will see.
...I guess I don't spend enough time on here, so I do not understand which "those" you are referring to, the finned/2.75 or the NOS/2.5... And I would very much like to see the pictures you refer to... where are they located? Sorry for the questions...
Allen
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: xs29j8]
#1158574
01/17/12 08:29 AM
01/17/12 08:29 AM
|
Joined: Dec 2011
Posts: 892
MA
steve70
super stock
|
super stock
Joined: Dec 2011
Posts: 892
MA
|
Here's a picture of Troy's T/A original rear drum
Last edited by steve70; 01/17/12 08:29 AM.
1970 Challenger T/A 4 speed
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: steve70]
#1158576
01/17/12 11:59 AM
01/17/12 11:59 AM
|
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
xs29j8
master
|
master
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
|
Quote:
Here's a picture of Troy's T/A original rear drum
IIRC, the original ones on my Challenger T/A look like the ones in the pic... Thanks for posting the pic!
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: floyd]
#1158577
01/17/12 12:32 PM
01/17/12 12:32 PM
|
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
xs29j8
master
|
master
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
|
Quote:
The original finned drums I have are just like Troys, with the small notch in the hub opening. The NOS ones do not have the notch. I'm just wondering what the purpose of the larger machined surface was? It's not like they used 2.75 inch brake shoes.
Finding the correct brake drum is turning out to be pretty confusing to me - there seem to be a lot of superseded part numbers.
From a Designer's perspective, the width of the machined surface would have to be greater than the width of the brake shoe to accommodate tolerance accumulation. With at least three of the parts in the tolerance stack being sheetmetal (+/-.030) plus at least four machined parts, a tolerance stack-up in the neighborhood of +/-.125 ((3x.030)+(3x.010)+(1x.003)= +/-.126)... i.e. the brake shoe's location would vary up to an 1/8 inch either side of nominal. I hope this makes sense...? Comments?
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: xs29j8]
#1158578
01/17/12 12:56 PM
01/17/12 12:56 PM
|
Joined: Jan 2003
Posts: 27,471
So Cal
autoxcuda
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 27,471
So Cal
|
Quote:
Quote:
Here's a picture of Troy's T/A original rear drum
IIRC, the original ones on my Challenger T/A look like the ones in the pic... Thanks for posting the pic!
Were yours painted black? What rims? Trims rings with dog dishes?
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: autoxcuda]
#1158579
01/17/12 01:16 PM
01/17/12 01:16 PM
|
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
xs29j8
master
|
master
Joined: Jan 2003
Posts: 3,624
Fort Worth, Texas
|
Quote:
Quote:
Quote:
Here's a picture of Troy's T/A original rear drum
IIRC, the original ones on my Challenger T/A look like the ones in the pic... Thanks for posting the pic!
Were yours painted black? What rims? Trims rings with dog dishes?
I do not remember if they were painted ... I will try to have a look this afternoon. 15 inch Rallye wheels...
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: xs29j8]
#1158580
01/17/12 02:22 PM
01/17/12 02:22 PM
|
Joined: Jan 2003
Posts: 4,115
MD
floyd
OP
master
|
OP
master
Joined: Jan 2003
Posts: 4,115
MD
|
Quote:
Quote:
The original finned drums I have are just like Troys, with the small notch in the hub opening. The NOS ones do not have the notch. I'm just wondering what the purpose of the larger machined surface was? It's not like they used 2.75 inch brake shoes.
Finding the correct brake drum is turning out to be pretty confusing to me - there seem to be a lot of superseded part numbers.
From a Designer's perspective, the width of the machined surface would have to be greater than the width of the brake shoe to accommodate tolerance accumulation. With at least three of the parts in the tolerance stack being sheetmetal (+/-.030) plus at least four machined parts, a tolerance stack-up in the neighborhood of +/-.125 ((3x.030)+(3x.010)+(1x.003)= +/-.126)... i.e. the brake shoe's location would vary up to an 1/8 inch either side of nominal. I hope this makes sense...? Comments?
It makes sense, but the later NOS drums I have with the 2.5" machined surface also used a 2.5" shoe. Did the shoes get smaller? In other words, do later versions of 2.5 inch shoes actually measure less than 2.5" wide? I have an NOS set of 70 11X2.5 shoes that measure 2.5 across.
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: Troy]
#1158583
01/18/12 04:43 PM
01/18/12 04:43 PM
|
Joined: Jan 2007
Posts: 1,163
NORTHERN VA
THESHAKERPROJECT
super stock
|
super stock
Joined: Jan 2007
Posts: 1,163
NORTHERN VA
|
Quote:
This is a very cool picture!! The drums were black because Steve's T/A had 15X7 steel wheels and Dog Dish hub caps...... if it had Ralleys then the drums would be red. Also do you see where around the one stud whole there is no black paint??.... that is where the retaining washer was installed for assambly.
....i miss that car....  
.....from your pic the drums look like grey phosphate...the same finish as the backing plates on most Mopars....did TAs have black painted drums? 
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: THESHAKERPROJECT]
#1158584
01/18/12 05:25 PM
01/18/12 05:25 PM
|
Joined: Dec 2011
Posts: 892
MA
steve70
super stock
|
super stock
Joined: Dec 2011
Posts: 892
MA
|
Black,here's another picture
Last edited by steve70; 01/18/12 05:26 PM.
1970 Challenger T/A 4 speed
|
|
|
Re: AAR/TA Rear Brake Drums??
[Re: THESHAKERPROJECT]
#1158586
01/19/12 02:04 AM
01/19/12 02:04 AM
|
Joined: Jan 2003
Posts: 27,471
So Cal
autoxcuda
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 27,471
So Cal
|
Quote:
Quote:
This is a very cool picture!! The drums were black because Steve's T/A had 15X7 steel wheels and Dog Dish hub caps...... if it had Ralleys then the drums would be red. Also do you see where around the one stud whole there is no black paint??.... that is where the retaining washer was installed for assambly.
....i miss that car....
.....from your pic the drums look like grey phosphate...the same finish as the backing plates on most Mopars....did TAs have black painted drums?
.
.
.
.
Quote:
This is a very cool picture!! The drums were black because Steve's T/A had 15X7 steel wheels and Dog Dish hub caps...... if it had Ralleys then the drums would be red. Also do you see where around the one stud whole there is no black paint??.... that is where the retaining washer was installed for assambly.
|
|
|
|
|
