I have a 86 951 with 90,000 miles. The front rotors are a little warped. What is everyones' thoughts on resurfacing. These rotors have never been resurfaced before. It only cost me $25/pair. Much cheaper than the 200.00 required for a new set.

 

You can resurface them, but the first time you heat them up to any degree they are going to warp again. Bite the bullet, put on new rotors and be good for another 70k or so.

 

Well, I don't think that's true. I haven't used resurfaced rotors on the 944 (yet), but I have on many other car without problems.

There's really only one thing you need to watch out for: make sure that they are thick enough before you have them resurfaced. If they are too think they will not dissipate heat correctly, and then they will warp. If they are thick enough you should be fine.

 

I've always felt that rotors are one of the cheapest parts for our cars. The later offset, MO30 ones are just about $100 per. Heck, a good set of brake pads can cost more than that per wheel. New rotors are a relatively little amount of money well spent.

 

Sorry, but that has been my experience on numerous 944's (and I do this for a living), as well as my jeep. They will be good for a short period of time, then you will have the same vibration again.

 

Warping is fairly uncommon, especially if your car is driven primarily on the street. Make sure you don't just have some uneven pad material transfer on the rotor surface causing the vibration. You can sand the rotors with garnet paper and rebed the pads. You never know, this may solve the problem, and only cost you $.41 for a sheet of garnet paper.

That being said, if they truly are warped, I would just replace them.

 

I guess I will try the garnet paper first. I have so many things that needs maintenance on the car right now, I am trying to find ways to save some cost. (Timing belt, Clutch needs to be done real soon).

 

In my experience the most common cause of brake rotor warpage is improper sequence when
tightening the lug nuts. Excessive torque (usually with impact wrenches) can also do it.

 

Are these the original rotors, with 90K miles on them? If so, I'd be surprised if they are above the minimum thickness. You'd be better off just replacing them if that's the case.

 

Yea with that kind of mileage just replace them.

 

While not on the 944, I too have experienced the warping after being cut. I currently have very warped rotors on the front of my S2 and will replace them very soon. I am considering cross-drilled rotors, but either way I don't think I'd cut them on a 944

 

My opinion, for what its worth..........

Measure what ya got. Dial indicate the runnout. Make sure its not due to loose wheel bearings. Just like standard procedures for any disc brakes.

KNOW what the min. thickness callout is. KNOW that you must have the rotors turned WHILE still on the hubs (don't remove them from the hubs). You have them turned/machined BELOW minimum, and yessiriee...........they WILL warp shortly thereafter. Even if everything else is good.

Decide what your gonna do with the car in the near future (race it, street it ONLY, or whatever).

KNOW, that sticky/bad calipers, are gonna destroy even the bestest, brand new rotors. Take appropriate action and KNOW if that might be the problem.........first.

Know, there is a difference in stock vs "preformance" pads, and what/how they can wear your rotors out faster.

"What is everyones' thoughts on resurfacing"

NO problems...............IF ya consider all above. THATS.........my thought.

 

Cross drilled rotors are a waste of money. I asked a brake engineer from TRW who is authoring a book on brake systems for the Socioty of Automotive Engineers and those were his words. He then went in to detail about why they are no good. Now slotting a rotor is a totaly different story and has merit if it is needed.

 

Well, except for that they look sweet!