Rear axle hub diameter

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Rogue-AE95
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Rear axle hub diameter

Postby Rogue-AE95 » Sun Jun 24, 2018 7:50 am

I need to know what the rear axle hub diameter is for a GTS axle. OEM would be better, but aftermarket like Weir would be nice to know too if they're different.

Edit: if anyone also has the MA46/47 Celica rear hub diameter, that would be great.

I mean that I need the diameter of the face of the hub. Not the centering ring / collar that the center bore of a disc rotor and wheel slides over (which is 60.1mm from what I gather). Thanks :idea:
'88 Corolla All-Trac x2 (manual, auto)

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jondee86
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Re: Rear axle hub diameter

Postby jondee86 » Tue Jun 26, 2018 4:06 pm

I've got a couple of axles here that were sold to me as being AE86 axles. The hub
outside diameter measures 139.6mm near enough with cheap calipers :)

The locating ring for the wheel measures 60mm and I think it is the center hole in
the factory wheels that measures 60.1mm for a snug fit.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
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Rogue-AE95
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Re: Rear axle hub diameter

Postby Rogue-AE95 » Tue Jun 26, 2018 5:55 pm

Thank you Jon! Always a font of information :idea:

For anyone who might need to know in the future, I measured appx. 14.5cm for the diameter of the AE95 rear axle hub. I'm curious if the AE86 SR5 rear hub is the same as the AE95, being both have rear drum brakes and don't have a disc rotor sliding over the hub like the GTS has.

I guess I should also ask... what is the thickness of the AE86 GTS rear hub? I'll have to pull off my wagon's drum and check it. I'm thinking about having the rear axles machined down in order to fit disc rotors on the AE95 rear axle, but I won't if it's going to be too much. Someone on the FB AE95 group said he did this...

I see my SR5 rear axle with discs upgrade topic has been bumped. I like the idea of those Hawk parts, but I would like to keep my parking brake, and be able to buy cheaper OEM type replacement parts (rotors, caliper parts). Very tempting though.
'88 Corolla All-Trac x2 (manual, auto)

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jondee86
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Re: Rear axle hub diameter

Postby jondee86 » Thu Jun 28, 2018 12:36 am

Rogue-AE95 wrote:I guess I should also ask... what is the thickness of the AE86 GTS rear hub?

I measured it at 9.4mm.

Cheers... jondee86
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persists in trying to adapt the world to himself. Therefore, all progress
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Rogue-AE95
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Re: Rear axle hub diameter

Postby Rogue-AE95 » Sat Jun 30, 2018 3:02 pm

Thanks again Jon... I just measured my AE95 hubs and they are just about the same. I can't seem to find my metric calipers, but my SAE calipers measured just under 0.375". Edit: found my metrics, and measured about 10.2mm...? Measured the same spot. Maybe one or the other is out of spec. But comparing one caliper to the other, the gap of the measurement is the same.

I find it interesting that the AE86 has 4x114 lug pattern and ~140mm diameter, and my AE95 is 4x100 and 145mm, yet the hubs are about the same thickness. The AE86 4x114 lug studs would be much closer to the edge of their hub than my AE95 and its 4x100 hub. There may be some wiggle room with machining the AE95 hubs. Just a matter of what is safe and what isn't. On the AE95 FB group, the question was raised about the durability of the hub being machined down in order to fit disc rotors over them. Someone else said that they had machined their hubs with no problems. :?

I was planning on fitting late model AW11 MR2 rear discs to my AE95 hubs, but the inside of the MR2 disc is about 130mm. So about 1.5cm of material would have to be machined off the AE95 hub. Interestingly enough the AE95 hub has a thinner section on the outside edge, beveled from the thicker part down to 4.65mm. The bevel starts around the 128mm diameter at the 9.4mm / 0.375" thickness, steps down, levels out, and ends up at 4.65mm for a few mm's of the remaining diameter.

Edit: measured about 14mm from the lug stud hole to the outside edge of the hub.

Here are some pics, if they will work:

Top view of AE95 hub:
https://lh3.googleusercontent.com/aehu5 ... 37-h709-no

MR2 disc sitting (backwards) on AE95 hub. You can see how small the inside of the rotor is.
https://lh3.googleusercontent.com/JDHD4 ... m8=s709-no
'88 Corolla All-Trac x2 (manual, auto)

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jondee86
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Re: Rear axle hub diameter

Postby jondee86 » Sat Jun 30, 2018 10:11 pm

0.375" = 3/8" = 9.52mm :)

I don't see any problem in machining the axle flange down to fit inside the AW11 disc.
Here is a pic of AE86 GTS axles for reference...

Image

In theory the if the studs stay in the same place, reducing the outside diameter of the
flange will have minimal effect on the strength of the axles. The axles should transmit
torque by virtue of the coefficient of friction and clamping force exerted by the wheel
nuts being correctly tightened. So having flat grease free clamping surfaces is the key.

The one thing you will need to sort is a locating ring to ensure that the disc remains
correctly centered on the locating spigot.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

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Rogue-AE95
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Re: Rear axle hub diameter

Postby Rogue-AE95 » Sat Jun 30, 2018 10:45 pm

OK thanks! As aside, there's one thing I wish the AE95 had, the larger GTS rear wheel bearings. AE95 uses the thinner SR5 type bearings.

Someone posted pics of an Audi A4 AWD, with 130mm diameter rear hubs. Although they looked thicker than 3/8", there's only about 3mm from the stud to the edge of the hub.

MR2 rear disc has 54.1mm hub, AE95 hub is 54mm :D If the pic above works, it's kind of deceptive because there's a bevel on the inside of the rotor's hub so it looks like it's floating on my AE95 hub. But it's neatly centered on it. That's one of the reasons I chose to work with AW11 MR2 parts. Same hub & lug pattern, no modifying of the disc necessary. But a lot of custom work to get them onto the AE95, like machining the rear hubs, custom caliper brackets, brake lines... :idea:
'88 Corolla All-Trac x2 (manual, auto)

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Rogue-AE95
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Re: Rear axle hub diameter

Postby Rogue-AE95 » Tue Jul 10, 2018 5:22 pm

I threw this together in AutoCAD today. I wasn't sure of the diameter for the lug studs, which seems to be about 14.22mm.

Edit: updated the image.

The red represents what my modified hub would be like. Since the thickness of the hubs are about the same, and from what Jondee said earlier, I don't have any qualms about going ahead with this. Someday...

https://lh3.googleusercontent.com/HKnDP ... 00-h550-no

I'm not sure if you guys can see the images I've been posting, but there's a direct link ^ to the image. Ever since Photobucket took a duke on everyone, I refuse to host images at the other free sites. So this is a roundabout way using the big "G" to host images :) If the image is blurred in my post as it is to my eyes right now, right-click and view image or click the link to see it full size.
'88 Corolla All-Trac x2 (manual, auto)