73+ A-body knuckle -- Drum or Disc?

Posted By: Molloy

73+ A-body knuckle -- Drum or Disc? - 12/19/08 12:56 AM

Can someone help me figure out what I bought?

I'm doing Andy's viper caliper conversion and I thought I bought the 73+ A body drum brake spindles. However, the spindle diameter is 1.25", not the 1.375" diameter of the ones coming off the car. The adapter plate bolts up great though. Do I have the wrong spindles?

Thanks,
Molloy

Posted By: 1_WILD_RT

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 01:01 AM

Drum spindle will have a four bolt pattern to attach the backing plate, Disc spindle will have a two bolt pattern to attach the caliper adapter.

Posted By: DoctorDiff

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 01:13 AM

Sounds like you have a B-body drum knuckle.

Posted By: Molloy

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 01:33 AM

Cool, so I guess I just need a different bearing set than what's installed in the 11.75" discs?

Posted By: 1_WILD_RT

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 02:06 AM

DoctorDiff has bearing adapters...

Posted By: DoctorDiff

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 02:09 AM

Unfortunately, you cant change the inner bearing and race.

I sell a cr-mo spindle sleeve and conversion seal kit to adapt the late rotors to the early knuckles.

E-mail me if you are interested.

Posted By: autoxcuda

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 02:10 AM

Quote:

Cool, so I guess I just need a different bearing set than what's installed in the 11.75" discs?

There is no conversion bearing set. I don't think anyone makes a adapter ring to make up for the diameter difference??

And the spacing of everything else might be diffrent. You need to contact AndyF direct. If B-body spindle would work, I would think he'd have them listed in his installation instructions.

Are you going to run the AndyF custom spindles, 13" and brembo viper calipers??

Regardless, sounds like someone sold you the wrong part. Was it misrepresented or guaranteed to be a 73 A-body drum spindle. Does the AR Engineering site and/or his instructions list a casting numbers on the spindles to ID them??

Posted By: autoxcuda

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 02:22 AM

Quote:

Unfortunately, you cant change the inner bearing and race.

I sell a cr-mo spindle sleeve and conversion seal kit to adapt the late rotors to the early knuckles.

E-mail me if you are interested.

Do you sell a sleeve for an original A-body disk to big bolt pattern disk (small or large bolt pattern)?

The 68 S/S clone guys would be interested in that as well as original 66-72 A-body disk brake owners.

Scott Harvey had special large bolt pattern disk made for the 66 Trans Am cars. And Bob Tarozzi worked on the 66 Trans Am effort and later was chief engineer and designer for the 68 Super Stock cars. Those special trans am rotor were used on the 68 super stock cars to get big bolt pattern to match the rear big pattern.

Posted By: DoctorDiff

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 02:27 AM

I haven't looked into a small bolt pattern DISC to large bolt pattern Disc swap, but I do make a small bolt pattern 10" DRUM knuckle to big bolt pattern disc conversion.

The small bolt disc/large bolt disc swap should be easy, however.

Posted By: Molloy

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 02:34 AM

I thought the difference between pre 73 A-body knuckles and the later ones was the ball joint, not the spindle?

Yes it was represented as a 73 A-body Drum knuckle. I bought them about 3+ years ago though.

Posted By: DoctorDiff

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 02:38 AM

The only difference between a '73-'76 A-body drum knuckle and any B-body drum knuckle is the diameter of the spindle where the inner bearing and seal ride.

Pre '73 A-body knuckles are totally different.

Posted By: autoxcuda

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 03:02 AM

Quote:

I haven't looked into a small bolt pattern DISC to large bolt pattern Disc swap, but I do make a small bolt pattern 10" DRUM knuckle to big bolt pattern disc conversion.

The small bolt disc/large bolt disc swap should be easy, however.

Looking to retain the KH calipers on a factory 66-72 disk brake car.

Significant market. As you go later into the 69-72 A-bodies, disc become more popular factory option.

The SSBC or MP conversions use a mustang rotor, mustang caliper, custom caliper adapter and bearing spacer.

If you could make a bearing spacer then... customers could buy one part, buy an under $50 parts store rotor and get big bolt pattern conversion.

Posted By: DoctorDiff

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 03:09 AM

Shouldn't be too hard because I already use an off-the-shelf 11.25" Mustang rotor for my SBP drum knuckle kit.

Posted By: Molloy

Re: 73+ A-body knuckle -- Drum or Disc? - 12/19/08 03:12 AM

Quote:

The only difference between a '73-'76 A-body drum knuckle and any B-body drum knuckle is the diameter of the spindle where the inner bearing and seal ride.

Pre '73 A-body knuckles are totally different.

Ah so then I have the correct knuckles and the wrong rotors. Guess we need to talk about the CrMo sleave.

Sorry for the ignorance. I've taken a 3 year hiatus from my cars and displaced the mopar side of my brain.