No need.........We have a wealth of knowledge in EVERY aspect of the A body here, with folks willing to share that knowledge. There is no such thing as a stupid question if you don't know the answer.
Need to know what kind of hubs I can use?
- Thread starter 19Dart74
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Probably. Unless the drums were swapped on.
These cars are like 50 years old so a lot can happen. Someone that ordered the car talked the dealership into taking the disks off, some drag racer thought they needed drums for less rolling resistance, somebody was parting this car and stole the disk set up for another car. Or yeah, it was a slant 6 car that’s had a V8 swapped in at some point. Also a good reason to check and see if the bolt pattern on the rear axles is 5x4” before ordering parts for the rear.
Thanks for the clarification.
doug 371
Well-Known Member
7/16 studs=small bolt 1/2 studs=big bolt
Usually. But then there’s the Wilwood disk conversions that have the 5x4” pattern with 1/2” studs. Or any of the new kits like Pirate Jack that have the same thing, BBP rotors/hubs set up with the 5x4” pattern and 1/2” studs.
Drums are usually a pretty safe bet, but you never know. The 7/16” studs are getting hard to find, and if your hubs were sketchy/loose you might be able to tighten them up by using larger studs. Obviously not without its issues too, but I would still measure the pattern.
doug 371
Well-Known Member
Absolutely
cudamark
Well-Known Member
Early '73 models (built in late '72) could still have had 9" front brakes. Those went away after the first of the year. They used the same spindle as the 10" brakes, so, they were a pretty rare animal. Speaking of spindles, inspect yours very closely for damage. That photo you posted makes me cringe! If damaged, either get a complete set from someone here doing a BBP disc changeover, or, bite the bullet and swap to that setup yourself. It will require new wheels though, and either a second spare, or, a conversion in the rear too.
The swap over date is in the TSB I posted, listed as approximately November 1, 1972. After that all the front drums would have been the new 10x2.5” design with the new large ball joint drum spindle. There is no new 9” drum brake mentioned, and the new 10” drums were run with 9” drums in the rear, which is in the TSB.
Before the changeover, the start of ‘73 model year production would have been early August 1972, when Ma Mopar would have been using up the prior year small ball joint spindles and the 67-72 version of the 9” and 10” drums. Then switched to the new 10x2.5” drums and spindles November 1, with no mention of the new, redesigned 9” drums. Because that’s why the TSB came out, it announced the changeover from 67-72 drum parts to 73+ drums and spindles.
So you’re saying that Ma Mopar designed a brand new 9” drum set up, to use with the ‘73+ large ball joint, larger wheel bearing 10” drum spindle? Then left it out of the TSB describing the new 10” drums that used the same spindle?
Got part numbers or pictures?
cudamark
Well-Known Member
Sure, all the '73 up model A-bodies with drum brakes use the 3402739 spindle, and 3722460-1 upper control arms, regardless of build date. The early production '73 low line models with the 9" front brakes used the 3699574 front hub and drum assemblies. I owned two of those early '73 slant 6 cars with that setup.
michiganpat
Well-Known Member
nope, my '76 is 5x4 with 10" front drums. bought from the original owner in 1991. build date 11/75. discs weren't mandatory by NHTSA until jan 1976.
MILO
Well-Known Member
Remember when you take the cotter pin out and unscrew the nut taking the drum remains off the bearings come out also so make sure you have them put in the same with bearings races and seal and Do Not over tighten when installing the nut just snug it with pliers and spin the drum a couple times and snug a little more only if need and if the lock clip dont line up back the nut off a little to put the cotter pin in I have seen these overtightened before and it will burn the bearings out quick
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