During my driver's ed this weekend in my first gen, I had both of my dust caps pop off the rotors on the track. I then had grease slinging out of the hubs onto the wheels. When I parked straight off the track, hot grease would run out of the hub down the wheel - no thicker than motor oil. In my search to find replacement dust caps, I pulled one off my wife's Miata. There was no grease visible - it must all be behind the lock nut and washer.

So, I have two questions,

1. Is it possible to over pack the hub with too much grease? I filled them as full as I could.

2. Did I use the wrong type of grease or does all grease become fairly liquid when hot? It was Castrol Heavy duty axle and wheel bearing grease that I used.

Thanks,
Neil

 

The reaso the MIATA showe little or no grease behind the cap is because it uses SEALED bearings ie the bearings have a seal built into the bearing itself. and the Cap just protects the end of the stub axel.

Yes grease will MELT at high temp. Get a COMPITITION grade grease or at least one labeled, FOR HIGH TEMP DISK BRAKE APPLICATIONS, or some thing to that effect. I think the Grease you mentioned may be intended for low temp uses like Trailers or drum brake equipped axels.
Also you want to leave a small amount of room in the hub as the grease will expand as it gets hot, usually the only problem with overpacking is the excess grease get pushed out and gets all over the place.

 

I don't overpack the bearings.. I just make sure grease gets inbetween each roller, and throughout all the crevasses, and install. I also use Redline hi temp axle grease, and stock caps, no problems with the caps coming loose so far.

PaulC

 

I agree with Paul, buy Redline grease it works the best, plus since its pink color will indicate the bearing are getting to hot if I gets really dark in color.

2nd, drill a small hole 1/16" in your dust cap to releave any pressure that might build up inside the brake rotor. That will allow for expansion on the grease and keep from blowing out the seal.

Don't over pack the dust cap, FYI I repack the wheel bearing after each race weekend.

John