Notchy rear wheel bearings

[oldgrey58]

Hi all,

I recently fitted new rear wheel bearings to my FC. They were Rare Spares kits.

When I fitted the wheels and gave them a spin, both wheels felt lumpy or notchy. The notchy feel is regular and say 6 to 10 times per wheel revolution and was audible as well in a quiet garage.

I'm sure it is the wheel bearings doing it and both sides the same. The car has done zero miles so far but has anyone else encountered this? Will they settle down?

The old ones ran smooth and I only replaced them because I had to fit something to NOS axles.

Cheers

[DCE80]

Are you certain it is the wheel bearings and not the diff you can hear when rotating the wheels?
If it is the bearings they won't settle in unfortunately.

[Maco]

Have you filled the diff with oil before spinning the wheels?
Cheers
John

[oldgrey58]

Hi,

Thanks for the responses.

Yep, diff is filled with oil and I thought it was the diff at first but got under the car the check. The feel and noise is definitely coming from the wheel bearing end of the axles. Both sides the same.

[DCE80]

Sounds like your only option now is to remove the axles. Did you rotate the bearings by hand on the axles after you pressed them on? Is it a standard diff (sealed bearings with oil seal inboard side)? 

Thinking outside the square you mentioned NOS axles. If bearings mounting diameters on shaft are a little on large side it can reduce clearances in bearings and present problems. A notchy feel happens as the bearing balls end up with small flats on them.

[FireKraka]

I agree with DCE you are going to have to take the axles back out, rotate the bearing by hand and you should be able to feel the notching if that is where it is.

Sometimes even new bearings can be stuffed if they have sat on a shelf for a long time they can frett in the races and this causes the very small flat spots.

I also thought the oil seal was on the outside of the bearing to stop road crap getting into the bearing and oil from the diff getting into the bearing to lubricate either that or completely sealed both sides.

FireKraka

[ACE]

Are you sure its the wheel bearings and not the planetary gears in the diff?
ACE 

[oldgrey58]

I'm very sure it's the bearings but to be sure to be sure I'm going to pull an axle out probably this weekend to check it.

[oldgrey58]

I pulled out both axles this weekend. It's not the wheel bearings as I had thought. They were hard to get out and I needed a slide hammer but that was due to the non hardening gasket sealer I used. Next time I used much less sealer.

To compare I fitted some old axles /bearings and it felt the same - slightly less maybe but too fine to be sure. I refitted the NOS axles / new bearings and they slid into place and out again with little persuasion so I reckon they are OK and not binding in the axle housing.

Turning a fitted wheel by hand you can't detect it. I can only feel it when I turn the axle by hand without the wheel fitted. Also there's no brakes fitted yet so it's not those.

The diff was reconditioned by a reputable firm and it's full of oil so I'm also guessing it's OK.

It's so long since I rotated an FC rear axle by hand that I am thinking this 'notchiness' is a normal feel to the diff - I can't remember what they used to feel like. 

[Dr_Terry]

I think you might just be feeling the side gears operating inside the diff.

These gears only operate against each other when cornering & even then only slowly.

If you rotate the 2 rear wheels at the same rate these gears don't move & there is no notchy feel.

Dr Terry