84bronzevette

for the second time in two weeks i've broken the flange clean off my front hub and bearing assembly while autocrossing. the first time the caliper kept the wheel and rotor contained in the wheelwell and the body incurred no damage. sunday it happened again, this time to the passenger side but the wheel tore up my hood and lower fender as well as the inner wheel well as it exited. the really strange thing is both times it happened to my wife, who drives much easier than the kids and i do. we run 315 35 17 hoosiers front and rear and have for the last three years with no problems before. i replaced the bearings two years ago (from midamerica) and they were still tight. has anyone had this happen and do you know of a more durable assembly for the early c4's.

thanks
scott

ZR1 MK

I would like to see pictures. What brand bearing? If you do a search here, you will see many opinions and facts about the bearings. I still have my originals on the rear with many track miles, but the fronts take a beating. They stretch apart a bit each track event. I only use CW/Chicago Rawhide because a few have reported bearing failures (C4 and C5) with other brands such as Timken.

freefall

Not much useful to contribute - only thought it that the caliper bracket bent while restraining the wheel the first time, and exerted some lateral force to the wheel bearing under breaking. Now the useful comments:


$750

$3000

Priceless!

larryfs

Autozone bearings are totally garbage. They only last 1 track day, and then I'm back in autozone arguing for a replacement.
Check the C4 section, where there is a recent discussion, but no real answers. Except the orginal GM bearings seem to last the longest.

wtknght1

YEP!!

AU N EGL

Autozone bearings and GM OEM bearings are both made by Timkin. GM has the GM Box and higher price

larryfs

then how come my OEM bearings lasted 8000 track miles, and my autozone bearings last 1 track day?

ZR1 MK

GM C4 bearings are made by CW. What is the GM C5 bearing supplier? I have only used GM/CW bearings.

STEVEN13

If I remember-you said (thru your post) you changed the bearings and put the car on the trailer. From what was posted on that thread-it seemed that others said the bearings had to be broken it. Randy R. from DRM was one who said this also.

I am puting the Autozone bearings in my C4-I hope they last!

Steven

larryfs

If the bearing comes in an orange box, you'll be lucky if they last 1 day.

larryfs

thinking about it: I should take my OEM passenger side bearing, and install it on the drivers side. And then put the new replacement on the passenger side.

too many right handed tracks around here

Solofast

When we were running the C4 in BSP we had a couple of failures of the hub flange on the bearing, I am assuming that this is what you are talking about here. What we found is that while the parts are "similar" they aren't necessarily the same, and some of them can fail in just a few autocross events with the added stress from sticky tires.

I was driving the first time it broke at a test session, and I really didn't notice anything was awry. Larry noticed a "funny noise" from the passenger side front wheel, and we crawled back to the paddock. If he hand't noticed it I woulda driven it till it fell off big time. Not to cause domestic discord, but these things do make some noise as they fail, and if you aren't perceptive you could keep going until the brake bracket fails....

The OE bearing that failed was from an 84, (which from the factory was weaker than the later cars because GM saw the problem in the Corvette Challenge cars and beefed up the part after that). We traveled to Indy from Grissom on a Saturday afternoon to get a new one.

We were a bit suspicious of new part from the start, from Carquest (I know, but they were the only place that OnStar could find that had one within 100 miles of Grissom). Anyway the difference between that part and the OE one was that the flange that holds the wheel studs was noticeibly thinner than the OE part and the hole in the flange (there is one large hole near the bottom of the flange) was bigger. Since the stock part obviously cracked from a fatigue crack that started in the edge of hole of the stock part (ok, I am an engineer trained in failure analysis) we were thinking we may have been in trouble. We used the new part for the rest of the test weekend, and the next weekend it broke. That is, after probably less than 20 runs it was gone. Same failure mode as the OE part, low cycle fatigue crack coming out of the bottom corner of the hole, but obviously at a lot fewer cycles, there was just less material and more local stress in the replacement part... Needless to say we have been using only OE style bearings for that reason.

Carefully compare any one that you buy to the OE part. If the flange is thinner, or the hole in the flange is bigger don't use it, you are just asking for trouble. You should inspect them whenever you have the wheels off the car, look for obvious cracks coming out of the edges of the hole. There was rust in the crack for maybe 25% of the way around the hub. It didn't crack in one weekend, and you should be able to see some visual signs of cracking at the base of the flange before it fails. If you see any sign of cracks, throw it away and start again...

Slalom4me

There are many threads in C4 Tech discussing bearing brands,
longevity, packaging & stamping marks, alternate p/n's, vendors,
prices and pictures.

CentralCoaster has been collecting and coordinating information
for a while. The results of this work can be seen in this thread

Alternate p/n for wheel bearings, pics, cheaper prices...

I took a quick look for the thread(s) that have many photos illustrating
characteristics of different bearings but didn't find it yet. It is
interesting for the discussions of whose bearings are actually in
the boxes at Pep Boys, AutoZone, NAPA and for that matter, ACDelco.

.

84bronzevette

thanks for all the responses / thoughts. the first failure was on the left side and the second on the right. i'm pretty sure i bought both from mid-america a couple years back right before our Nelson Ledges event. the failure was sudden both times although my wife said she heard something while negotiating the turn right before the turn it failed in. the brake was right where the spindle flares into the flange - from now on i'll be inspecting them before each event although i'm not sure there was any obvious fatigue before the failure. i'll be buying GM bearings from now on.

thanks;
scott

larryfs

another failure...
1/2 day of hard street driving killed a brand new AZ bearing. I was driving around town with my hooisers on, and that was enough to loosen up the bearing.
I admit I didn't break it in as some people are talking about, I just put in on and a few hours later there is play in it....

Bill Dearborn

Larry,
How much play does it have in it? They can have some play in them and still be good. Several years ago a friend and myself changed bearings on our C4s and noticed they had play in them as soon as we finished our first track session. We left them that way and never had a problem.

Missed you at WGI last Wed and Thur. First day was sort of bummer since we lost 4 hours of track time to heavy fog.

Bill

AUTO_X_AL

I think the issue is that the GM part is not even made by GM. New departure is the outsourced producer that makes the ACDelco part and many other aftermarkets. The only problem with the aftermarket is that it is more or less a crap shoot. It could be a ND part or a timkin or anything else for that matter. The Delco part will always be the good ones. I forgot how but you can tell a ND from others because of a unique casting mar. I had 2 federal moguls loosen up in probably 15 runs and we took them off in order not to have a more catastrophic failure. My ABS light illuminated and I lost ABS as a result of the bearing loosening and breaking the internal clock wheel that runs the ABS. Our car is an 86' which was the first year for ABS and was our only indicator of anything bad happening.

larryfs

enough play to annoy me. not enough play to be concerned with. Maybe I'm just too saftey concious because it's a track car. I like everything tight.

joemoia

I've got the Timken bearings from Autozone on both front and rear and they have lasted longer than the original bearings, and I've been running R compound tires on the Timkens vs. GY F1 SC's on the origianls.

88WHITE VETTE

I work for bearing co. and one of our plants makes the hubs for brand new cars. As I was talking to some guys from that plant, I found out that the best quality hubs go to the factory and the ones with some small blemishes, (but othervise good) go to the dealers for the spare parts. Ones that failed the quality inspection have good chance to go to the after market stores.
Timken is probably doing the same thing and buying at the dealer gives us better chance to get the better quality wheel bearing hub.
I have 88 and have some play on them and will be replacing them soon. I was hoping that my co. would be making parts for GM, but they don't.