Need really good rotors.

M

maxmk8

Registered
Ok the steering wheel shake is bad, I am about to throw away another set of rotors. Please note i have 13 inch cobra brakes and rotors that i decided to purchase after not beeing able to get rid of that annoying vibration when braking. It makes my car feel cheap and old. I need to know some really good rotor brands and where I can purchase them. Are those cryogenically (frozen) rotors any good? I would like to have them slotted or drilled for the look, since obviously it does nothing for my warping problems.

btw I used proper brake in procedures where I gently stopped from 35-5mph 6x. Then let the car sit and let the rotors cool down. I also went really easy on them for the next 5 days. Within 2 month the damn shake was back. I do not think i can machine these rotors because they are drilled and slotted so i need a new pair.

In case anyone wonders I torque my wheels to 90 pound feet.
 
RE: Need really good rotors.

[div class="dcquote"][strong]Quote[/strong]
I used proper brake in procedures where I gently stopped from 35-5mph 6x. Then let the car sit and let the rotors cool down. I also went really easy on them for the next 5 days.[/div]
Max - was this with ceramic or semi-metallic pads? The procedure you described is for semi-metallic.

John
[link:www.goldengatemark8.com|Golden Gate Mark VIII Website]
http://mark8.org/users/johnaec/Mark_VIII_s.jpg
'97 Mark VIII LSC
'96 T-Bird 4.6L
 
RE: Need really good rotors.

[div class="dcquote"][strong]Quote[/strong]
...semi's need almost full stops from 60 or so...about 8 stop and goes. Then drive without using brakes (if you can) until brakes cool..[/div]Hmmm...I thought the procedure you mentioned was for ceramics...

Here's also some other info: http://www.stoptech.com/whitepapers/warped_rotors_myth.htm

I take the above-mentioned paper with a grain of salt, though. The author mentions he's never seen a warped rotor in 40 years, that instead they've all had uneven material build-up. Well, when I had my last set turned, the operator said they were warped so bad he almost couldn't bring them down to spec. And yes, I'd followed the hard break-in procedure and torque all the lug nuts to 90 ft/lbs that time. They did last almost 10K before much warping, though. That was with ceramic pads - I'm going to try something different the next time...

John
[link:www.goldengatemark8.com|Golden Gate Mark VIII Website]
http://mark8.org/users/johnaec/Mark_VIII_s.jpg
'97 Mark VIII LSC
'96 T-Bird 4.6L
 
RE: Need really good rotors.

Yeah - I just waded through 7 pages of google searches on warped rotors - it's unbelievable that car manufacturers can't come up with a better way of preventing it than just crossing your fingers...

John
[link:www.goldengatemark8.com|Golden Gate Mark VIII Website]
http://mark8.org/users/johnaec/Mark_VIII_s.jpg
'97 Mark VIII LSC
'96 T-Bird 4.6L
 
RE: Need really good rotors.

NOT a solution BUT, a money saver. Had the same problems with my T-Birds and Mk's. Go to O'reillys and buy the "lifetime guarantee" rotors. They have replaced my rotors several times, FREE!!
 
RE: Need really good rotors.

Start by skipping the cross drilling and slotting. that just creates stress risers and impairs the rotors ability to absorb heat. plus, it means you can't have them turned when they start to warp.

also, buy a torque wrench and make sure you torque the lug nuts on your front wheels properly every time.

i don't know about the cobra brakes, but i use NAPA rotors. they have two options, get the expensive ones.
 
RE: Need really good rotors.

Max, I assure you(with you as my witness) I hand torqued the right front to 90 lbs when i swapped your fuel filter!


Seriously, is there a Mark VIII that hasnt had the shimmy at some point?

Max, are you sure your FE suspension is all tight? radius(strut rod) arm bushings/tie rods/UCA/LCA, etc?

Just a thought.


[a
Club 16 President/Founder
94 Black/Black M8
97 Toreador red/Lt. graphite LSC M8
V.P. GGM8​
 
RE: Need really good rotors.

+1 on the suspension. The same thing happened to me so i'm replacing every piece of rubber up front (including tires) and now i've got the car on jacks waiting for the stock cobra rotors to get here.
 
RE: Need really good rotors.

I swear it's those aftermarket wheels and the hubcentricity issue + worn suspension. Your rotors are fine.
 
RE: Need really good rotors.

Hmm alright first a few responses.
1). I have a torque wrench and I hand torque my wheels to 90.
2). Front suspention will get a closer inspection but I need to know where to start. ( I will take pics of both sides of it maybe you guys can see a problem since i think my bushings look good.
3). A lot of people have those wheels and reported no problems so I have to believe that it is a problem with my car. But I still have a set of my other wheels, I will swap them on when time permits and I will have to see if the situation improves.
4). My front suspention was almost completely rebuilt 40k miles ago. (bags, steering rack, and a few other things). I sure hope they used new bushings that time.
5). I think the Pads are semi-metallic since they are the stock Cobra pads.
6). I have a problem while driving (steering wheel shakes), and while braking (Steering wheel shakes more).
 
RE: Need really good rotors.

if you have a problem while not braking you have a problem outside of the rotors. not to say the rotors aren't the problem, but they aren't the only problem.

when you get the rotors off, take them someplace to be turned. Even if you don't actually turn them, putting them on the lathe and spinning them, then moving the cutter in until it just barely touches will reveal whether or not they are warped fairly quickly.
 
RE: Need really good rotors.

Max...the ONLY problem right now is, I dont have any 18" wheels(or 17's) to slap on your car to further troubleshoot the issue.

I dont think its the rotors. it's either strut rod bushings, tie rod end(s) or LCA bushings.

A picture might help, but I doubt it as there is no way a picture can depict the amount of play in any suspension component.

Bushings that "look good" can be just days away from failing.

I remember checking your tie-rods for end play while you were on the rack, as well as the bearing play and I disnt feel anything "loose". I am at a loss buddy.


[a
Club 16 President/Founder
94 Black/Black M8
97 Toreador red/Lt. graphite LSC M8
V.P. GGM8​
 
RE: Need really good rotors.

my car has a bad motor mount (or 2) right now and it's the only vibration left. It actually causes the steering wheel to shake, even when I'm not moving (only when it's about about 2500 rpm). So just for the hell of it you might want to put your car in drive, put the brakes on hard and hit the gas. If the engine moves more than a 1/2 to 1 inch it's time for new mounts. They can be a cause of vibration too.
 
RE: Need really good rotors.

The rotors on my Mark VIII need replacement every 20,000 miles because they get warped and the steering wheel shakes like crazy when I apply the brakes.

I had a 1973 Chevy Malibu with front disc brakes. Those rotors never warped.

Alexander
Board of Directors
Lincolns of Distinction
 
RE: Need really good rotors.

I have had my Autospecialty power stop rotors for almost 50k and they are still good. Before that the OEM would start to warp about every 10k.
 
RE: Need really good rotors.

I have put over 40k miles on my Mark with nothing more than a pad change front and rear using stock rotors, and I have no shake using ceramic pads in front. I get build-up shake once in a while, but usually a couple "safe - all clear" panic stops makes the shake go away.

One thing that has not been mentioned in this thread that I believe is a preventative maintenance item for me to reduce the rotor overheating, and longer pad life front and rear, is setting the parking brake to adjust the rear brakes. I set the parking brake every time I start the Mark, and I think this is the main reason why I have no issues with my brakes with over 90k miles. I have not read anywhere that the rear brakes on the Mark are "self adjusting", so maybe this info might help with your next set of rotors.
 
RE: Need really good rotors.

I have 169,000 miles on my '94, bought it with 34,000. I have not had any problems with what I presume are the original rotors. I put new pads on about a year ago, expecting the rotors to be shot, the rotors looked great. I was one happy camper (until I tried screwing in the rear calipers xo , I've got the good caliper tool set now.)

Jeff
 
RE: Need really good rotors.

While going through my 98 Ford Workshop Manual looking for brake vibration info, I read the following in the diagnosis and testing part of the brake system section, pg 206-00-6:

"If vibration can be felt while applying only the parking brake, use a hub-mount brake lathe to machine the rear disc brake rotors", and it also says: "If vibration is only felt while applying the brake pedal, use a hub-mount brake lathe to machine the front brake rotors."

Here is the key... "Ford recommends on-vehicle rotor machining"

Has anyone had their rotors turned while they are still on the car? If yes, did it help?
 
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