911rsq

I am redoing my front brakes on my '91 Z28 w/J65. I go to the parts store, buy the "J65/Z28" rotors, inner and outer wheel bearings, and seals. I get home and dry fit the bearings to the hub. The inner is the correct size, but the outer that I was sold was to big??? I thought something must be wrong so I go back to the parts store the next day and ask why the bearing doesnt fit the rotor. Parts guy does some checking and FINALLY finds a smaller front outer bearing, but says it is for the base model Camaro and non-Z28 cars, not the "better" J65 cars. I decide to go home and tear the brakes down to see what's on the car in the first place. My rotors come off, and sure as can be, smaller outer bearings????
I thought the J65 was an "Upgrade" from stock. Why would the outer bearing on the upgraded brakes be smaller than those ont he regular Z28s? Anyone else run into this problem? I just figured with all of the suspension and brake options this car has that it would have the larger outer bearings for better performance reasons. Anyone have any ideas?

Edit - P.S. the rotors that came off of the car match the "J65" rotors I bought for the car, so I am pretty sure those are right?

Apeiron

J65 is the RPO for the rear brakes. Were the front brakes listed specifically as "J65" brakes, or was it listed as "performance package"?

Performance package refers to the 1LE brakes, which use the larger Set-3 bearing. Everything else uses the smaller Set-34.

911rsq

That's a good question. If I remember right it was rears we figured out first, because those were actually the ones I really needed. Since it was listed as performance for the rear, I think we may have assumed that the fronts were as well. I do know that he asked if it was 1LE, and I said no. He did sell me the Set-3 bearings, not the set-34, which is the one we went back and found. I am pretty sure he had another bearing listed as well. I am going back in the morning to take back the Set-3 bearings, and I am going to see what that was.

If I recall correctly, he didn't even have the Set-34 bearings listed under the Z28....how odd.....

Thanks for the info Apeiron......we will know tomorrow...

ebmiller88

iTrader: (7)

It depends on where you go to get the parts. At Autozone, if you say it's a "Z28", you'll get parts for a Performance Package car. If you say "RS", you'll get the standard stuff. The other bearing you saw was probably the inner bearing, Set 6, which is the same on all '82-92 F bodies.

Ed

911rsq

I went back today, but was in a hurry to get to work, so no chance to have him look it up again. I just walked int and bought some A-34 bearings..... They fit perfect when I put them in 10 mins ago... . I did get a set of the A-6s, for the inners of course
Thanks for all the help. Fronts are on and looking great. I with it was the same story with the rears. One of the PBR rotors is frozen and I am gonna have to get it rebuilt, or buy a rebuilt one......
P.S. anyone know how much endplay you are supposed to have in the rear axles on this car. It's not a lot but it seems like too much....

RBob

iTrader: (1)

The books at CarQuest are the same way. They list the Z28 as having the 1LE bearings.

RBob.

911rsq

YUP.....checked it out....Advanced Auto Parts lists ALL Z28 as having the Set-3 Bearing (1LE). All is well in brakeland here now. The fronts are all installed and fit nicely. The rear calipers go in to Mid-Illinois Caliper Co on Monday to get completely rebuilt.
It's gonna be nice to get her on the road again soon!!!!!!!

JPrevost

This might be off topic but why would GM bother putting 2 different sized bearings together in our cars? Having a large inner and small outer makes it as weak as having 2 small bearings on both sides! What a PITA. The larger "1LE" bearings are the same as the B-body bearings correct?
The only good thing about having smaller outer wheel bearings is you're more likely to check them out on an frequent schedule. And if they're in good shape more likely than not the inside's doing okay.
As for the parts store holding "Z28" = 1LE well that's typical for the kind of usual customer they get. If it was "1LE" people would just be asking to give them whatever fits their "Z28" lol. Too many variations in models. I haven't been into cars that long but I've learned to always bring in exactly what I need to avoid arguing with the parts counter guy that his computer was programmed by a dim whit!
They always start by asking what car is it for and I tell them to step away from the keyboard while I explain my position that it's FOR a 91 camaro but the part I need isn't listed under that model. lol... "can you bring out a 99 vette rotor, a 99 f-body rotor, a knock sensor from an 87 L05 1500, a knock sensor from a 96 L31, and a few sealed beams for an 86 volvo? Thanks."

ebmiller88

iTrader: (7)

LMFAO!!!

Ed

911rsq

..... I'm in tears.....
What's funny about the whole this is that the Set-3 bearing which is in the 1LE fronts really isn't that much bigger than the Set-34 which is in everything else..... Like JPrevost said...why 2 diff sizes, why not just use the bigger and be done with it. I cannot imagine that the very minute size difference would make THAT much difference out there????

ebmiller88

iTrader: (7)

GM should have just used the Set 3 and be done with it. This is also the bearing size used on the Impala, Caprice, and other "big Chevy" front rotors.

JPrevost

In their defense it was smart. Save a buck on the wheel bearings and you've saved $1 x 400,000 = $400,000 , but I agree they should have stuck with the 12" big bearing rotors on everything to have simplified things.

ebmiller88

iTrader: (7)

Funny thing is, Set 3 bearings are $9.99 at Auto Zone, Set 34 is $10.99 (Timken).


Ed

JPrevost

haha, well GM's special like that. Actually it's probably more expensive because it's not as popular but when GM bought in bulk you know they saved money with the lighter part.

911rsq

I went with the Federal Mogul bearings. Although, Timken is what came out, I cannot justify putting a bearing with plastic retainer in my car...... plastic is for toys. The Mogul bearings were all steel.

Apeiron

Whenever I buy Timken bearings, they're always steel.

911rsq

the ones that came out of this car were Temken and had the plastic outer retainer.....I REALLY don't like those. The plastic stretches over time and the bearings get loose.....

911rsq

I just went out and dug thru the garbage in my garage to try to find those bearings.....they are buried...... I was gonna try to post a pic of them....

ebmiller88

iTrader: (7)

Yes, Timken Set 34s have a plastic retainer.

Ed

911rsq

Sweeeeeet....someone else has had them too. I hate em and wouldnt trust them on a Rustang.....

JPrevost

Thanks for that heads up.
If you could take a picture of the bearing I'd appreciate it. Maybe even pull it appart to be certain that the plastic is the retainer and not just the seal. I don't see how ANY plastic could be made to handle the job of retaining those rollers.

ebmiller88

iTrader: (7)

Yes, it's not just a seal, it's the retainer. Actually, if you think about it, all the plastic really does is keep the bearing rollers in place and in line. Once you get them torqued down the races do the rest. Still, I would prefer metal retainers but Timken is a good bearing, I use them exclusively, and I've had no issues with them at all.

Ed

911rsq

I will have to admit, I have used them in the past with no problems. I will have to admit also that when I have taken them out, the plastic is stretched and flimsy over time. I know the bearings have no where to go once they are installed, but still.... I use Federal Mogul now and have no probs. Timken is good too...