Curveit

NDH, SKF, Chicago Rawhyde, all the same thing. I just purchased mine today at Pep-Boys. $159 and $139 w/life time warranty. There's talk of increased rear bolt TQ numbers now; up to 200 ft/lbs, but it's still up in the air if this is better than the factory 164. I'M going with 180 as a compromise. PS..... these numbers are for manual trans. Just thought I'd add to the confusion.

No Go

I'm still unclear why a manual would be different than an auto. Factory service manual makes no such distinction... :confused:

I noted using some oil on the threads-why? Well I did a wheel bearing change on a front wheel drive car (much more involved-press, etc) and the FIRST time I did not use lube on the huge nut (similar to Corvette size) and I destroyed the bearings (at a 100 a pop) when I pulled out of the driveway.

Did it a second time with more new bearings and some oil on the nut...I was able to turn the nut much farther as the torque spec came up (expected)...I don't recall if the manual called for it. Car worked great then...my impression was the strength from the assembly relies on a properly torqued nut integrity. Once the torque is reduced it quickly fails-like my case.

The shock from the trans doesn't impact the nut at all-goes directly thru the splines...so confused on why this is coming up.

Rick93Z07

Somebody was manufacturing billet rear bearings on the forum less than a year ago for about $400/pr. In addition, I seem to recall some folks retrofitting $80 front F-body bearings to the C4. They reamed out the mounting flange threads on the bearing assy with a drill bit.

larryfs

any tips on how to torque the 3 bolts down to 66ftlbs?
I can't get room to swing the torque wrench. well I got the bottom bolt, but not the other 2.

Tomorrow I'm going pick up a 3/8 TW and see if that'll fit in there....

Mr6spd

Since these were obviously under-designed by GM, I recently sent a brand new pair out for Cryogenic treatment (just got them back today). I'm hoping for 2-5x longer life out of these.

But don't just send them anywhere for cyrogenic treatment. Talk to Rick Diekman (847)-651-5511 of Controlled Thermal Processing. He is most helpful, and is the Chairman of the ASM sub committee on cryogenic treatment of metals. Their website is http://www.metal-wear.com/

Tell him that Dan sent you ;)

I also had him cryogenically treat a pair of new beautiful 300M Billet spindles from Chris at Speed Demon motorsports: http://www.speeddemonmotorsports.com/

The entire hub/bearing assembly was cryogenically treated. If properly done, the procedure will not harm the grease or the seals. The process takes the part slowly down to -300F and then back up again (a 3 day, very slow process). The cryogenic temperatures improve the grain structure of the steel, and dramatically improves the wear and fatigue properties of the bearing races and roller elements. You can do some reading on their site to learn more.


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[Modified by Mr6spd, 7:10 AM 5/7/2003]

larryfs

I have to wonder about the grease and the seals even though he says they won't be harmed.

anyway, you will have to be the test mule and let us know how it works out :D
Mine is going back together this week as the 96 manual has the wrong torque spec for the caliper bracket (166lb-ft), and I busted a bolt. :mad

larryfs

also I don't like the studs in the new bearing assembly from NAPA. I wished I had changed them to GM studs before putting it back togther.....

Monks

I had the exact same thing. It was the rear bearing. I had new A/C
Delco bearings put on the rear about 500 miles ago. I run only autocrosses
and I use Goodyear slicks. I developed a chirp and clicking noise from
the drivers rear. I bought a $145 PepBoys (Chicago Rawhide) bearing
and replaced the bearing yesterday....noise is gone. The old bearing
had lots of play between the bearing and the stub shaft, the new bearing
was fine. BTW, the old bearing was greased, and torqued to 200 lbs.

Russ

Monks

Use 94 Firebird Formula front bearings. You don't have the drill
anything, just run the bolt from the other side, through the knucke
into the bearing housing.

Of course this is for the front only.

Russ

ZR1 MK

QUOTE: NDH, SKF, Chicago Rawhyde, all the same thing. I just purchased mine today at Pep-Boys. $159 and $139 w/life time warranty.

If GM bearings are from the same manufactuer, are all the bearings made to the same specifications? I was information by someone that after inspection of a failed bearing, while in track use , the bearing construction didnt look the same.
Mike

larryfs

I just finished my bearings. failure analisys of the old bearings.... It seems the grease leaked out, and thus the bearing ran dry or ran dryer that it should. Both sides had grease throw around the aluminum hub. something caused the sealed to fail.

mk2001c

"Mine is going back together this week as the 96 manual has the wrong torque spec for the caliper bracket (166lb-ft), and I busted a bolt"

Larryfs - I noticed the same thing. Almost 100 ft/lbs more than any other car I've worked on. Good thing I don't have a torque wrench that goes that high or I'd probably have tried. What are the correct torque settings for the calipers?

larryfs

someone emailed me with a 70lb-ft spec from another year manual.
technically you should replace the bolts anyway. I have the part numbers if you need them.

I also brought a 3/8 torque wrench to torque down the torx bolts. The monster torque wrench doesn't swing too well in that tight area.

mk2001c

Larryfs,

I would like that part number. And just to confirm - the 70 ft/lbs is for the brake caliper bolts. Thanks.

larryfs

call Dal and ask him for the 6 bolts he just sent me. (Larry)
4 bolts that have an 18mm head, hold caliper bracket to axle flange.
and 2 smallish ones that hold the caliper closed.

I used 70 lb-ft and drove it around the block. seems fine.
I have to find the receipt with the part #'s on it......

Jsmizira

@monks What brand do you use? timken/moog/skf? Do you know if they are tapered roller bearings? Are those year Firebirds heavy compared to our 'Vettes?

Sorry for the noob questions.

RedLS1GTO

Holy *****.

You do realize it has been 11 years since the last post in this thread, right?

Jsmizira

Crap! no, I didn't. I'm new around here. I don't yet know the ways of the Forum.

RedLS1GTO

To answer the question, the best C4 front bearings are SKF F-body bearings as stated. Your info shows an '86 Vette so to be completely honest, I'm not sure they will work for you. It's been a while since I have looked, but I believe the ABS plugs are different.

This is what I used for years on my '96 track car.

http://www.jbr17llc.com/skf-br930186.html

The website doesn't look like much but it is legit. Seemed to me like a husband/wife type of deal. I actually called and ordered over the phone to make sure and the woman I talked with was very helpful.

There are different opinions out there about having to drill the threads to make them work but that is 100% NOT NECESSARY. All you need to do is run the bolts through from the other side, exactly as they are installed on the F-body. If you want, you can put the Corvette nuts on in addition. I did for the sole reason of holding my spindle ducts (and so I didn't lose them)

With all of that said, please pay attention to the difference between years. I know these worked on my '96. I don't believe they will work on an '86 for the reasons listed. Perhaps somebody else can verify.

Jsmizira

@RedLS1GTO

Thank you for the information and for humoring me.