dizwiz24

I had my c4 corvette on jacks and was able to get a slight amount of rear wheel play If i put one hand at 6 oclock and the other at 12 oclock. The fronts didnt do this.

The car has 71k with about a dozen autox and 6 high speed road course events. Mostly uhp street tires.

The play is not from the ujoints. I replaced those. It seems to be hubs.

Is this normal?

if i do need rear hubs which should i get? Unfortunately ac delco rear c4 hubs do not appear to be avail thru corvette recycling anymore....those would be my first choice.


Timken? Are they still made in usa?

Any advice is appreciated!

Rob31

Yes that is normal . They loosen up after a couple events . and stay that way for a while , just keep an eye on em . I got a good set from Oreilys . Make sure they say USA
Stay away from plain white boxes ,China ,Korea ,anything like that .Autozone sucks too .

dizwiz24

Thanks.

I cant tell you how annoyed id be if i went out and bought a set of new hubs and they had the same amount of play!

Im not getting any unusual inner shoulder rear tire wear either (just the usual slight bit from the negative camber)

Just to be safe, im going to go in there and re check my rear axles wheel nut torque. Ill make sure its > 150 Ft lbs. Ive heard 165 is a good torque to be at

c4cruiser

Any play at all in the hubs typically indicate that replacement are needed. Our autocross association holds annual tech inspections and the car are on a hoist so wheel bearing play is checked. Any movement that is found is noted on the inspection sheet and the car owner is told that the bad hub needs to be replaced.

There's another thread in the C4 Tech section about the quality and cost of C4 hubs. The last front hub I installed was a Timken unit clearly marked as being "Made in USA".

I just finished installing both rear hubs on my '87. One hub had a good 1/4" of play and the other was just showing some slop. Both hubs were original to the car and they had 6 seasons of autocross using A6's and also had 6 years of track days.

As far as torque on the spindle nut, the FSM will say 164 ft-lbs. Some people have mentioned that GM updated that to something like 200 ft-lbs but nobody has found proof that GM actually published that new value. Because the nut is a castle nut and has a cotter pin and cap, if the pin is still there there should be no reason to think that the nut has backed off.

Also expect some rust in there. The FSM says to torque the nut with the tire off the ground. So you will need somebody to depress the brake pedal or place a wedge between the tire and ground.

jaa1992

what year C4? I know on my 92 the rear axle nut torque is in the 200 ft lb range.

Also by a little wiggle are we talking measurable (0.25 in range) or "did it really move" range.
Between the two I'd check after EVERY event. When it gets in the measurable range - time to change. You do not want it to look like my passenger rear when I changed it the first time, it came out in two pieces!

FYI- I did not replace the castles over the axle nut once and was caught in tech with a "movement" in the hub. the nut had backed off a little, torqued it down and passed tech. A couple events later it was time to change it. Got almost 14 events outta that hub

dizwiz24

We are talking about in the 'did it really move' play...

Not measureable by any means. Though i can feel/hear something off axis (a tiny bit) when strongly manipulating the rear wheels - which is why i am postng this.

The fronts are rock solid.

The other 'clue' is each rear side has an equal amount of this.

You guys who have had rear hubs go bad....was it worse in one side vs. The other?

I imagine it would be because most circular courses are biased with more turns one way than the other.....

Thanks for the replies

93Rubie

Ok, it have literately hundreds of auto-x runs on my rear hubs. One unit is a Wheel Bearings Inc. and is still tight as it was no, ZREO slop. The other was a close out National/Federal Mogul unit from Rockauto.com, after 2 seasons still tight as can be.

There should be zero slop. I'm happy with the WBI unit and would purchase again. Supposedly made in the USA, I don't remember for sure.

Both fronts are Moog units and nice and tight. Finally got the OEM's to get play after 3 seasons of auto-x.

ALSO, you could have perfectly good bearings and the rear diff. could be worn that the half shaft is sliding and out a bit. Mine is just starting to do this. When I have the rear end apart this next off season for clutch packs, I will put in selective fit washers to correct this as long as the play is not too much. Tom's Differentials has all this stuff, just FYI.