Hey guys,
What is the differance between 1972 and 1975 brake rotors for the front?
And is 1972 and 1975 rear brake rotors the same? I have a 1972 1.7 4 lug and want to put all the suspension from a 1975 on the car. If I do.... do I order 1975 rotors front and rear?
And what is the best and cheapest place to buy rotors?
Thanks guys,
Seth

70-later 72 same in the front late 72 after 4722919033 to 76 the same. The two have different offsets to accomodate differences in calipers (thicker pads on the late) and the centering circle on the late (much better set up!) Cannot be interchanged without changing the struts.

Rears are all the same on the fours.

Thank you much DR.

Fronts have a different offset "depending". Depending on the build date in 72. Rears are the same.

We went through this with a car out East. Rich was going to get some measurements for us because he had ton's of rotors layting around...

I suspected that the rotors could be interchangeable as long as the calipers followed suit. The early (1970-1972.5) calipers have a different offset to accomodate the rotors.

Best indicator is the "Centering Ring" on the rotor. If it has one you generally have a later set up. Early front rotors don't have the centering ring.

Also, look at the calipers. Early calipers have one bleeder and 7mm Ribe head "through" hardware with an 11mm nut on the back end. Later calipers have two bleeders and hex head 7mm hardware with a machined nose for them to screw into (no nuts).

If you use the 75 suspension (calipers and all) for sure, you would order the later parts.

Hey George, can you weigh in on this? I've never had a pair of each strut laying around with the rotors etc. I was told yes and no. No "real" answer. The only thing i have now for referrence is my car and that has Koni struts on it

Eric the early so called "split strut" has to have the early rotors and calipers that wear the thin pad. The late "solid strut" has the taller rotors with the wheel centering circle and the calipers that wear the thick pads. Of course the split and solid refer to the balljoint hole in the bottom. Nothing will interchange except for the wheel bearings, and strut inserts. The factory even made two different pedrinni wheels to fit the different rotors.

Same wheel bearings... seems the spindle is identical. Which has me wondering (follow me here)

If I had an early split ball joint strut and I slipped a late (centering ring) rotor on it, would the "late" caliper then slide over that rotor and bolt up to the ear?? We had a car that seemed to have that combo (wish I could recall the thread and the member). It was back in Mass or somewhere...

Looks like you're definitly saying no.

Found the thread and bumped it.

Click Here

Yes there was the late 72 that used the late caliper but the early balljoint. Very rare and like one of the guys said a crossover. So odd it is only worth mentioning in passing. (we have also seen the late rotors without the centering circle on these same late 72 cars!

Does that mean late rotors will fit on early struts as long as you bring the calipers to the party?

That means that late rotors and calipers will fit the odd transition late 72 strut that had the late offset with the split balljoint hole. Late calipers and rotors will not fit the standard early strut. That transition strut is very rare (late 72 only) and is not desirable anyway as it uses the bad early balljoint assembly that even porsche superceded

Cool. Mystery solved. There are 3 struts for the 914-4.

Whew...

And... that's a weird one. Hard to imagine Porsche (or Boge) tooling up for a few hundred of those 72 tubes.

And as George indicated, 3 rotors as well. However, the transition rotor was used only a short while, and most will have been worn out and replaced by now. Not likely that anyone will see one again.

You guys are great.
You make me laugh and learn stuff at the same time.

Oops.
what did you want to measure..I can do it tommorow...the Ice has left the building.

Rich

That was when I was exploring the theory that all struts may be created equal and only rotor and caliper offsets made the difference.

It now appears that there are three struts and three rotors for the -4's

(It would be cool to see all three side by side.)