10 replies to this topic

[tadleysimon]

just put new bearings in my rear hubs and fitted them to the radius arms.

when i torque the castle nut the hub doesnt lock up and can still be turned by hand but its much stffer than the rear wheels on my mini thats on the road.


now i understand that the bearings need time to bed in so is this normal? or should the hub spin freely?

cheers all

[sonikk4]

Providing you have used the correct torque figure it will be fine. New bearings do feel a little tight to start with so what you can do is run the car for a short journey then recheck the torque for the bearing.

Providing you can turn the wheel without having to use too much force then all should be well.

To give you an idea when we fit aircraft wheels there is a larger loading/seating torque which we apply while spinning the wheel then this is backed off then the lower torque setting is used which is the final torque. Remember though this is on a wheel unit weighing over 300lbs but the principal is the same.

[Sprocket]

It has a lot to do with a bearing freshly packed with cold grease. It gets better over time. There will always be some stiction though since the purpose of the torque on the hub nut, is to create a pre load on the bearings to prevent the balls or rollers from sliding in their races. It is this pre load that increases the stiction, but it is an important factor in the life of the bearings. There should be no lumpyness and the effort, or resistance in turning the hub hould be even throughout the rotation.

all considering that the bearings have been installed correctly in the first instance.

There are certain manufacturers that list a force that is required to start the hub turning indicating the correct bearing preload.

Edited by Sprocket, 09 March 2011 - 07:56 PM.

[Gulfclubby]

We actually had to change the bearings once after not having punched the rings in far enough and snug to the lip inside the hub. The attempt to tighten the hub nut then slightly bent the bearings and rendered them unusable. They were quite hard to turn even without having torqued down the nut to spec. Cleaning the hub of any metal debris, dents and such then allowed us to properly press in the new rings and fit a new set of bearings. Then torquing down and spinning the wheels was no problem at all anymore. Lesson learned: when fitting a new set of bearings, clearances of much less than millimeters make huge a difference. Down drive around with a stuck bearing or it will overheat and fail.

[tadleysimon]

thanks all,

i pressed the races in all the way for sure, there all packed with fresh grease and free from any rubbish.
anyway, i torqued them down and as has been said, the resistance is even through a full turn and there isnt a huge effort involved,
there easily turned by hand but do not spin freely so im happy all is well,

the split pins i got in the when bearing kit are way too big though so that sucks...

[bmcecosse]

The hub should spin EASILY. If it's tight - something is wrong. Maybe it is too much grease - but I rather doubt it. Is this a Timken taper roller bearing set ? Is the spacer present between the two bearings ??

[tadleysimon]

tapered rollers yes,
the spacer is built into the inner races,
outer races are fully home

like i said, i reckon its fine

[Sprocket]

The hub should spin EASILY. If it's tight - something is wrong.

I think its down to individual perception and your comment doesn't really help. what is meant by 'spin', 'easily' and 'tight'. Can you quantify this?

A hub with new bearings freshly packed with grease installed and torqued correctly will turn with little effort, but it will not 'spin'

If you have followed the book, there is no uneveness or roughness when turning the hub, and little effort is required to turn it, it fill be fine.

On a side note, the rear taper bearings do not have a spacer, and, the inner races do not touch when installed, theres almost a 0.002" gap.

[bmcecosse]

Any rear tapers I have fitted - have a loose spacer between the bearings - and YES - they touch up tight on that spacer. And the hub will 'spin' if twirled round by hand and then let go. I do however use CV joint Moly grease in the rollers - there may be a different result if using heavy/thick grease. Perhaps bearings sold these days have a spacer built in ? I still maintain it should NOT be tight - and certainly with the wheel/tyre fitted it should spin round easily and continue to spin when hand power is removed!

[Sprocket]

Any rear tapers I have fitted - have a loose spacer between the bearings - and YES - they touch up tight on that spacer. And the hub will 'spin' if twirled round by hand and then let go. I do however use CV joint Moly grease in the rollers - there may be a different result if using heavy/thick grease. Perhaps bearings sold these days have a spacer built in ? I still maintain it should NOT be tight - and certainly with the wheel/tyre fitted it should spin round easily and continue to spin when hand power is removed!

well, the last taper bearings you must have fitted would have been well over 15 years ago, since the factory fitted bearings in my 95 sprite do not have a spacer, and nor do the inner races touch. I have measured the gap between the bearings on a fully torqued up hub, can you say the same? Properly packed wheel bearings in a hub, will not 'spin' since the stiction of the grease is too great. Has nothing to do with being over tightened or over packed with grease.

You als change your advice as to what you mean by 'spin' since everyone on here is talking about the hub, and not the wheel. Of course if you spin the wheel it will continue to spin, there is more mass to overcome the stiction. Can you now see what I was trying to get at. You know exactly what you mean, but the way you put it across easily leaves it open to interpretaion by others.

I am also confused as to wy you are using a sliding joint grease in a rolling bearing aplication

Help yourself to help others by not bothering.

Edited by Sprocket, 11 March 2011 - 12:54 AM.

[Andywade]

Your bearing is fine m8 , if you used the timken rollers and the grease that came with the bearing, then the wheel will easily turn by hand but wont continue to spin after-wards - its just because the bearings have not beaded in and the grease is packed in tightly.

Changed my Rear wheel bearing exactly the same as you - built in spacer in the races etc etc. take the car for a spin and then check the bearing again, after 50 miles or so. Re torque it as necessary and you should be good to go.