Front Rotors - Model Year Differences? (1 Viewer)

[zerotreedelta]

In prep for doing my front axle knuckles, grabbed some new rotors, ordered for my '76 MY. However, when I went to drop them on, they're different from the originals...the 6 holes are more stud-sized than bolt sized, although there are two bolt-sized holes.

Some sites do still show these for the '76...but others show them only for 80+. I'm assuming they're for a stud-through mounting hub, but that's not how my early '76 is...can anyone confirm? Worst case, I could probably zip the other 4 holes in, plenty of meat there...or track down another set and donate these to someone that can use 'em...they're out of the return window at this point.

 

[bikersmurf]

Companies like NAPA have discontinued the 76-78ish rotors. I used them the last time by drilling out 4 news each. Studs go through the hub and then the rotors are mounted with six bolts to the hub. The 79+ have the studs going thtough the rotors and two extra bolts to secure them.

I used the old rotors as a jig and drilled the 4 new holes in the rotors. It wasn't worth it to me to return the two rotors, and buy two more for twice the price... rather than drill 8 holes. The rotor is hub centric so the percise locaation of the hub isn't critical.

Others have used washers to fill in the space.

 

[zerotreedelta]

Good deal - I did the same last night as well, just hadn't had a chance to reply. Used the original rotor as a guide, and banged out the other four holes.

One of those quirks of having the transition year type rigs...seems like a few parts like that on the '76s.

 

[Pitter Patter]

In prep for doing my front axle knuckles, grabbed some new rotors, ordered for my '76 MY. However, when I went to drop them on, they're different from the originals...the 6 holes are more stud-sized than bolt sized, although there are two bolt-sized holes.

Some sites do still show these for the '76...but others show them only for 80+. I'm assuming they're for a stud-through mounting hub, but that's not how my early '76 is...can anyone confirm? Worst case, I could probably zip the other 4 holes in, plenty of meat there...or track down another set and donate these to someone that can use 'em...they're out of the return window at this point.

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I have the reverse issue of this. Mine is an 81 and I’ve gone through 3 different vendors (including Toyota) seeking rotors with the extra two assembly holes. Super annoyed because I returned my OEM rotors to the dealership, they claimed the 8 hole ones aren’t available and these will work. I then ordered through CCOT. Spoke to them and specifically asked for the 8 hole rotors as pictured on their website. They assured me this is what they would send me. Same OEM 6 hole rotors showed up. So… I’m in the process of assembling these without adding those two extra bolts but is seems like there is excess slack in the rotor to hub. The wheel studs don’t seem to be designed to sink deep enough into the hub to hold w/o those extra assembly bolts. I can always take this apart… again. And use a drill press to add those two extra assembly holes but that’s another PITA.

Question for those who have been through this. Is it really okay to mount without the assembly screws? Or should I go drill these out?

Thanks everyone

 

[4Cruisers]

When I did my '86 build four years ago I used new rotors without those two holes, no problems at all. I pressed the studs in with my HF 20-ton shop press.

 

[-MaTTi-]

I drilled those 2 missing holes by myself. Now they are like OEM.

 

[Pitter Patter]

Decided to drill the rotors out for the assembly screws, used the old rotors as a template and used a drill press. Turned out well. Fit on the hub is perfect.