Rear wheel bearing - stiff when new?

The American · Postby **The American** » Thu Oct 17, 2019 3:37 pm

I’m in the process of fitting SADFab mr2 hubs that use standard Mx5 rear bearings.

I used a press to assemble the bearing in the upright and to fit the hub into the bearing. Everything when together smoothly.

Now, with the axle nut torqued to spec, the wheel is very difficult to move.

Is this a normal experience with fresh rear bearings, or have I potentially muffed something?

RS2000 · Postby **RS2000** » Thu Oct 17, 2019 5:07 pm

Did you support or drive the correct bearing ring, so that there is zero load going through the balls? i.e. Drive the bearing into the upright via the bearing outer ring, & support the bearing inner ring from underneath when driving the hub in.
Sorry if questioning that is an insult! Cheers

The American · Postby **The American** » Fri Oct 18, 2019 7:11 am

RS2000 wrote:Did you support or drive the correct bearing ring, so that there is zero load going through the balls? i.e. Drive the bearing into the upright via the bearing outer ring, & support the bearing inner ring from underneath when driving the hub in.
Sorry if questioning that is an insult! Cheers

Yes, I used the old bearing to press the new one into the upright, and the a socked from underneath to support the center of the bearing while pressing in the hub. For one side, I did not have the socket positioned quite right and the center of the bearing moved a little when I started to press in the hub, and I had to press it back in. Both sides are as tight as each other, however.

plohl · Postby **plohl** » Fri Oct 18, 2019 4:08 pm

They loosen up a bit. Mine were stiff, but smooth when I did them recently dude... but it really comes down to what we're defining as stiff. I could still move mine by jamming my fingers in it and rotating them. Easier once the hub was in, but definitely not free spinning.

The American · Postby **The American** » Sat Nov 16, 2019 9:57 pm

Just to close the loop on this, as posted elsewhere inner bearing seals are not fitted to some later NB’s (approx 2003 onward).

I had installed new rear hubs, bearings (which are fine) along with seals. It turns out Mazda did away with the seals for later models and they don’t actually fit my car.

The ‘tight new bearings’ was actually the seals being clamped between the axle ends and the uprights.

Now with the seals removed, the axle and bearing spins freely with the axle nut torqued to spec.

:oops: