1997 z28 w/abs... i ordered new rotors for all four corners, and started in on the rear only to find that the axle shaft flange is too large for the rotor to fit over it. the new rotor casting is clearly expecting a smaller flange size. is this because the car has abs? i ordered online from a parts place and specified my cars particulars, however i didn't see anything asking about whether or not it had abs or any other criteria that might dictate a different choice. i haven't checked the front ones yet, was too pissed off about the rear ones being wrong ...

and since i am now going to have to order new rear rotors, anyone want to point me in the right direction? looking at this set on amazon ->

 

I don't believe there is any difference between ABS and non-ABS rotors. You likely just received the wrong part or someone incorrectly specified the vehicle it fits. Personally, I would go for a normal set (not slotted and drilled) of rotors on Rockauto from Powerstop or another reputable brand. Slotted and drilled rotors are great for racecars that need to consider every bit of weight and cooling, but on a normal "street car" they can be dangerous. If you would still like to go with a slotted and drilled option make sure that they are produced by a reputable source. Here is a link to the rotor section on RockAuto: https://www.rockauto.com/en/catalog/...hub,rotor,1896. The prices are usually great and they arrive in an unholy amount of time. I ordered a fuel pump recently, it was shipped from their warehouse twenty-five minutes later and showed up at my house in only three days. Hopefully this helps

 

well... rockauto was where i got the ones that don't fit, and it seems to be impossible to reach anyone from customer support, AND their "automated" site and system has already decided i'm not allowed to return them because the parts i received are exactly as depicted on their site which was presented to me as a valid choice for my vehicle. there was not sufficient information for me to have any shot at knowing in advance these wouldn't fit (i.e., "axle flange size xx" or some such). guess i'll end up going to a local auto parts store where i can take the old one with me and make sure i get something that's right.

thanks for the suggestion on drilled/slotted vs. normal. i'll consider that.

 

In the 93-96 model years the rear axle hubs were slightly larger than the front hubs. The 94-96 wheels were made with larger hub holes to match the rear hubs, so the wheels/tires can be rotated. I've heard stories indicating early 93’s had different size hub holes on front and rear wheels, requiring tires to be dismounted to rotate them. The mismatch occurred when GM pulled the rear axle assembly for the S10 pickups out of their parts bin and decided to use it in the 4th Gen F-Bodies.

At some point, late in 96 model year or early in 97 GM resized the rear axle hub to match the front hubs. And they made the wheel hub holes smaller so all 4 wheels were now hub-centric. Unfortunately, anyone who tried to put 97 and later F-Body wheels, or OEM wheels from a Corvette on a 93-96 had to open up the hub holes slightly to match their larger rear axle hubs.

Shoebox indicates the mismatch was corrected in 1998.

4th Gen LT1 F-body Tech Articles

Appears either someone swapped an earlier model rear axle assembly into your car, or it was early production and ended up with a leftover 96 rear axle assembly. Measure the diameter of both the front and rear hubs. If in fact the rear hubs are larger than the front, you should be able to order rear rotors for 93-96. These are the diameters I have seen posted on an F-Body wheel site. May or may not be correct???

front wheel hub = 70.50 mm

rear wheel hub = 70.75 mm