Now that Centric is gone...what now for Disc brakes with 5x4 SBP
- Thread starter Miranthis
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Yes the caliper as well as the seals were hitting prior to taking the rotor to the lathe. They seem to be original calipers, but I did get them at a parts store and had to provide the old ones for cores. Its my understanding there was only one caliper made. Having written that I do know that there are aftermarket calipers out there, are you suggesting they could be different dimensionally?
Ford 9" and chrysler 7 1/4" axle bearings are proof that there is nothing wrong with ball bearings for axle bearings. Millions of miles on that type of bearing
Yup. Don't say that too loud. The green bearing haters will hear you. lol
Sure they will last 100,000 miles or so of normal driving. The original tapered bearings will hold up to road racing and only last 400,000 miles, so far. But you are able to repack them with grease and they are adjustable. Ask green bearings for the axial load for their bearings... They never replied to me. It all comes down to intended usage. Obviously most of this old stuff is plenty beefy for most of us.
There were reproduction calipers, kinda crazy to see the calipers touch the rotors. I have some original virgin K-H rotors, swedged studs and all. I'll try to get some measurements and pictures of the rotors in the next day or so.
66FS, You may be on to something here. There are a lot of people here myself included that would benefit greatly knowing that this isn't a rotor issue, its a caliper issue. If so, it would be great to be able to determine which calipers fit the current replacement rotors.
320,000 miles on my 71/4.
350,00 plus on my mom's 6 cyl Ford mustang.
7 1/4 only lasted me for around 100,000 miles they were making noise and were shot. I'll probably never get past 400,000 on the 67 Barracuda 8 3/4. I want to redo everything but the pumpkin (3.23 Powr Lok) including the axle bearings and seals. They have done enough. My friend road races a Mustang in American Coupe. It runs a 9 in Ford with full floating axles, 2 tapered bearings per side. He told me he would never run green bearings, that was enough for me. However you are probably misunderstanding where I stand. Green bearings are inferior, but it is no big deal. Just like comparing the various 8 3/4 and Ford 9 in pumpkins. They will all last plenty long enough, for most of us. I don't think your 7 1/4 or you mom's Mustang bearings would last as long for me.
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Slantsix64
Well-Known Member
Sorry I meant I bought rotors and pads off rock auto recently not a conversion
Green bearings are in every single front wheel drive and AWD car made. For decades now. The ones in our Ford Escape have over 200,000 miles on them. Course now that I've said that, they'll probably start going out. You can spout all that stuff you want, but you're parroting everything you've seen on the internet and it's wrong. But that's ok too. You can be wrong. You'll still wake up tomorrow.
Actually I'm right. I agree those bearings are fine for most people. I am not parroting anything. I do not read the internet. I am a mechanical engineer and know the differences in bearings. I have a friend that actually road races and wins whenever he runs, he doesn't mess around with good enough. The original bearings in an 8 3/4 are super heavy duty. It is way cheaper and easier to buy and run Green bearings and they are fine in most applications, but they are not equal in radial or axial strength than the tapered needle bearings that came in 8 3/4 rears. I grew up working on these cars and know how to pack and adjust bearings (my Grandfather taught me), front or rear and they will last forever, no matter how I abuse them.
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Ok. Ifin you say so. I'm plum proud of your education and experience...and I'm not bein a smartass. Lots of people don't have that opportunity. But last I checked, we weren't talking about road racing.
I'm not trying to brag, but we did have to research stuff and had to defend choices with published data. I tried to get data from Green bearings years ago now, and they would not respond. Timken publishes all kinds of data for their bearings. Road racing is the hardest on wheel bearings because of the side loading. Not a Green bearings strong point, but for most they work plenty good. That was all I was trying to say. But I can't agree that greens are as good or better than the original bearings.
fstfish66
Well-Known Member
have you tried scar bird ? he has kits that use off the shelf parts,he supplies the adapter plate for the caliper, GM style, and a list of parts and part numbers to get from the parts store, no special parts, been doing this for many years, theres another one his name escapes me at the moment,,,
I'm not saying that one is better than the other JUST that Ball Bearing axle bearings are not the scourge of the earth that some make the out to be.
Of course a full floating rear hub (like Trucks use) would be the ultimate in performance, no pressed on axle bearing retainer to slide off etc.
8 1/4 uses non tapered roller bearings right on the axle shaft. And we don't hear about failures all day long or side load issues with the axle keeper against the axle gear in the diff.
67 Dart FSM
7 1/4 with ball bearings
65 Ford Mustang FSM
9" with ball bearings
Of course a full floating rear hub (like Trucks use) would be the ultimate in performance, no pressed on axle bearing retainer to slide off etc.
8 1/4 uses non tapered roller bearings right on the axle shaft. And we don't hear about failures all day long or side load issues with the axle keeper against the axle gear in the diff.
67 Dart FSM
7 1/4 with ball bearings
65 Ford Mustang FSM
9" with ball bearings
All I can tell you is my experience says otherwise. But I can agree to disagree. I have some bearing knowledge, myself. Ever heard of the company Bearings and Drives? Look it up. It was founded in Griffin, Georgia and later moved to Macon, Georgia by a man named John Nations. My mother, then Nan Yandle and Uncle, Bruce Yandle helped found that company. I'm not an engineer and certainly don't claim to know half as much as you obviously do, but I know some people pretty high up in that company that'd argue your position. But again, I can agree to disagree. To me, they're just different type bearings that do the same job.
I stumbled across this looking for parts for Diff rebuild. They might know a thing about bearings also.
Yukon Rear Axle Bearing and Seal Kit for Chrysler | AK C8.75-GREEN | RANDYS Worldwide
Technical Notes
- These bearings are not recommended for daily driven vehicles or for trucks. The OEM design, part number AK C8.75-OEM, is a much better design for those applications.
My experience is the problems begain with the rotor castings somewhere around 1999.
The dust boots have always been very close to the 'hat' to begin with.
Also in the old days the replacements were sold as an assembly with the hub and balancing weights in the rotor.
IMO with replacement rotors its even more important to be machined as they won't be balanced with weights. Arguably the closer to the center, the less important a slight imbalance will be. But the eccentric shaped 'hat' is really unacceptable in my book.
I htink I have some measurements in a notebook somewhere.
This was on the Centric website, but doesn't have the diemension we're discussing.
I'm sure they do. But it sure is funny that MILLIONS of trucks have been using the sealed green style hub bearings now for decades and you don't see them piling up on the sides of roads from failed bearings. Understand, I'm not arguing with you. I'm just stating fact. If green type bearings were a big problem, we'd know it.
Interestingly, your photo of the original has very little taper in the hat, current offerings are more cone like. I've had recent experience with machining the hats on two current versions of the replacement rotors from Summit The amount of material that must be removed from the hat is a minimum of .1250" in order to not rub on the seals. Keep in mind the seals will expand a bit in use, so mine have had about .1500" removed, and have about .0250" clearance from seal to hat to allow for expansion of the seal. Its not a simple process as you have to remount the caliper each time to check clearance. Its best to use a lathe that can chuck the assembly with hub installed, otherwise you have to remove the hub from the rotor and reinstall to check clearance with caliper installed. Using a lathe that can only chuck the rotor through the center, you may have to remove the hub and repress the studs in and then remount on spindle, bolt on caliper to check clearance. Sure would be nice if they fit right out of the box!
Wow! That is a lot of work! Be careful you don't get the cross section too thin. On the Ford Taurus the cross section was too thin and occasionally the rotor would rip off the hat.
Yes, brother. I pretty sure OEM bearings are a higher quality than Green Bearings. However, I never said they were a problem, I just said the Original bearings were better.
Yes, the wall thickness of the hat is a concern. That's why I had to take it a step at a time, the less material taken off the better, but without machining the hat it simply is unsafe as it will wear through the seal. Having written that, I have 2 pair of old swap meet rotors, worn past their limit, bought for the hubs. The hat wall thickness I ended up with was comparable to the thickness of the old worn rotor hats, about .220" to .230" . The newly machined rotors on the car have a hat wall thickness about .230" That's the first I've heard of the Taurus rotor hat failures, I owned an '87 Taurus, and had issues with warping rotors, but no hat failures, fortunately.
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