When was the last time you changed your rear hubs?
03-21-2017, 06:08 PM
#222
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Ok, so I just bought a few of the Dorman 930-550 rear hubs from Rock Auto for around $15/ea.
They are made in China.
They are drilled with a ~0.552" hole for the wheel stud.
The closest 'murican drill sizes are:
35/64=0.5469
9/16=0.5625
The closest metric drill size:14mm=0.5512
These are the ARP wheel studs which are specified for the 94-05 rear. ARP says they have a 0.579" knurl diameter, so that means I can measure good.
I really don't know what size stud they should be.
The ARP 100-7717 has a knurled diameter of 0.565", which is 0.006" smaller than the original studs. The 100-7720 is 0.008" oversize.
I had no issues installing the 100-7720 with my hazard fraught ball joint press.
They are made in China.
They are drilled with a ~0.552" hole for the wheel stud.
The closest 'murican drill sizes are:
35/64=0.5469
9/16=0.5625
The closest metric drill size:14mm=0.5512
These are the ARP wheel studs which are specified for the 94-05 rear. ARP says they have a 0.579" knurl diameter, so that means I can measure good.
I really don't know what size stud they should be.
The ARP 100-7717 has a knurled diameter of 0.565", which is 0.006" smaller than the original studs. The 100-7720 is 0.008" oversize.
I had no issues installing the 100-7720 with my hazard fraught ball joint press.
The Dorman Taiwan hubs have the proper rear hole size. The China hubs do not. If you are replacing studs, IMO, you have to start with US or Taiwan hubs.
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03-21-2017, 06:50 PM
#229
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No offense, but I would throw those hubs and studs in the trash. Hole diameter is .551, press-fit is .005-.008, and you pressed a .028" oversize stud into a part which is already known to be weak enough to require regular time-out intervals. Way, way too sketchy for me.
The Dorman Taiwan hubs have the proper rear hole size. The China hubs do not. If you are replacing studs, IMO, you have to start with US or Taiwan hubs.
The Dorman Taiwan hubs have the proper rear hole size. The China hubs do not. If you are replacing studs, IMO, you have to start with US or Taiwan hubs.
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03-21-2017, 06:55 PM
#230
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If I use standard interference fit clearances, such as you listed, then even the stock studs are the wrong size on the Dorman hubs. I'm not a design engineer or machinist and have found nothing online about clearances for interference fit joints with knurling. Hopefully we can come up with a cheaper solution than buying OE replacements from Mazda. I can buy a stack of Dorman hubs and get them reamed at the machine shop for less than 1 OE part.
I can't see any problems with reaming Chinese hubs to the proper dimension, so long as the geometry and metallurgy of the rest of the part is adequate.
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03-21-2017, 07:19 PM
#232
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Drilling and reaming 4 holes is worth $80 to me. I'm not on that bay area salary life though 
Last edited by aidandj; 03-21-2017 at 07:58 PM.
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03-21-2017, 07:30 PM
#234
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And I suspect Savington's labor rate is high enough that it's not worth his time.
--Ian
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03-22-2017, 01:10 AM
#237
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I went with Madza comp hubs, for a couple of reasons. #1, guaranteed to work. #2, guaranteed to work.
Pictured also are lovely Madzacomp brand new rear knuckles. Why? A couple of reasons
a) original uprights with this car are 180k and no ABS. I am installing ABS. For those not in the know, this requires new uprights all the way around, unless you possess mad machining/fab skills not available to mw, The mounting points for the abs sensors are not machined on the non abs uprights.
b) used rear abs uprights are problematiic. How many miles do they really have? I purchased some, and they came with bearings and dust shields, but the rust factor was real. For a track car seeing 2x+ oem power, I questoned them. Also one of the dust shields was bent during shipping, not the fault of the seller, but. But. My experience with separating 100k+ mile rear knuckle components is bad, here in the salt free NW. I didn't even contemplate trying to take the bearings and dust shield out of those uprights. So I just bought new.
For your internet amusement: New Uprights (w/bearings, as MazdaComp ships them), new rear hubs. Deadblow Hammer. Win. As with so many things, apply lube and hammer it home. The pipe products pictured are 1-1/4". Floor adapter, nipple adapter, joiner. 32mm socket.
Pictured also are lovely Madzacomp brand new rear knuckles. Why? A couple of reasons
a) original uprights with this car are 180k and no ABS. I am installing ABS. For those not in the know, this requires new uprights all the way around, unless you possess mad machining/fab skills not available to mw, The mounting points for the abs sensors are not machined on the non abs uprights.
b) used rear abs uprights are problematiic. How many miles do they really have? I purchased some, and they came with bearings and dust shields, but the rust factor was real. For a track car seeing 2x+ oem power, I questoned them. Also one of the dust shields was bent during shipping, not the fault of the seller, but. But. My experience with separating 100k+ mile rear knuckle components is bad, here in the salt free NW. I didn't even contemplate trying to take the bearings and dust shield out of those uprights. So I just bought new.
For your internet amusement: New Uprights (w/bearings, as MazdaComp ships them), new rear hubs. Deadblow Hammer. Win. As with so many things, apply lube and hammer it home. The pipe products pictured are 1-1/4". Floor adapter, nipple adapter, joiner. 32mm socket.
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