Front Wheel Bearing Assembly - lubricate spline?

[Spinman]

Getting ready to change a front wheel bearing assembly (1996 Aurora)

Correct me if I'm wrong, but I thought the units were sealed - and thereby required no additional bearing grease to be added during the life of the unit.

There is an instruction sheet in the bearing box that instructs me to fill the kuckle cavity with multipurpose grease after mounting the bearing in the kuckle assembly. Then install the seal in the kuckle recess - and then insert the drive axle through the hub and tighten the axle nut.

So it sounds as if they want me to lubricate the spline area (and not the actual roller bearings - which are sealed, duh). When I removed the old unit - there was no apparent wear on the spline or the mating surface of the old bearing units. Also, no obvious grease from the old installation. Nothing that was dirty, sticky, or oily. Everything was clean, smooth, shiny steel. So I doubt that the kuckle cavity was filled with grease when the garage replaced the bearing the last time. Is this a requirement?

Also, concerned about filling the cavity with grease - would that not interfere with the electronic module that is on the back of the bearing assembly? (And perhaps that is why I don't see any evidence of grease loading)

I'm thinking that the installation sheet is too generic - and not applicable in all details for the Aurora.

What about using anti-sieze on the drive axle spline instead of grease.

****************

Another question -

The shop manual shows that the axle nut should be tightened to 107 ft/lbs.

Attached to the bearing was a tag stating that the bearing differs slightly from the OEM design, and requires a minimium amount of axle torque that may differ from the specifications in the service manual. The bearing must be tightened to 180 ft/lbs to ensure proper bearing pre-load.

Are they telling me to tighten the bearing to 180 ft/lbs and leave it at that setting - or after I seat the bearing, should I loosen the nut and re-torque it to the factory 107 ft/lbs?

I asked the counter man at the parts store - and he said to leave it at 180. Just wanted to get a second opinion - dont' want to create premature bearing wear if I tighten it too much.

*******************

How much in/out movement is there with the drive axle and bearing during suspension flexing and steering movements? Is the grease on the spline necessary to insure free movement - or is everything pretty much 'locked into place' after the axle nut is installed and tightened.

And speaking of the axle nut - if there is an allowance for the in/out movement - will setting the axle nut at 180 ft/lbs instead of 107 ft/lbs reduce the amount of allowed movement designed into the vehicle by the manufacturer?


I'm thinking that the in/out movement is basically non-existant - the axle position is locked into place when the axle nut is tightened - and that 180 would not make any difference vs the 107.

Appreciate any input.

Thanks -

[maxwedge]

Originally Posted by Spinman

Getting ready to change a front wheel bearing assembly (1996 Aurora)

Correct me if I'm wrong, but I thought the units were sealed - and thereby required no additional bearing grease to be added during the life of the unit.

There is an instruction sheet in the bearing box that instructs me to fill the kuckle cavity with multipurpose grease after mounting the bearing in the kuckle assembly. Then install the seal in the kuckle recess - and then insert the drive axle through the hub and tighten the axle nut.

So it sounds as if they want me to lubricate the spline area (and not the actual roller bearings - which are sealed, duh). When I removed the old unit - there was no apparent wear on the spline or the mating surface of the old bearing units. Also, no obvious grease from the old installation. Nothing that was dirty, sticky, or oily. Everything was clean, smooth, shiny steel. So I doubt that the kuckle cavity was filled with grease when the garage replaced the bearing the last time. Is this a requirement? Is there a seperate seal behind here the bearing mounts to the knuckle if so get some grease in there but not too much or the seal will not go in, this more or less to keep water out, not really for lube purpose and yes you can use some ant- seize on the axle splines for ease of future removal, no much though.

Also, concerned about filling the cavity with grease - would that not interfere with the electronic module that is on the back of the bearing assembly? (And perhaps that is why I don't see any evidence of grease loading)

I'm thinking that the installation sheet is too generic - and not applicable in all details for the Aurora.

What about using anti-sieze on the drive axle spline instead of grease.

****************

Another question -

The shop manual shows that the axle nut should be tightened to 107 ft/lbs.

Attached to the bearing was a tag stating that the bearing differs slightly from the OEM design, and requires a minimium amount of axle torque that may differ from the specifications in the service manual. The bearing must be tightened to 180 ft/lbs to ensure proper bearing pre-load.

Are they telling me to tighten the bearing to 180 ft/lbs and leave it at that setting - or after I seat the bearing, should I loosen the nut and re-torque it to the factory 107 ft/lbs?

I asked the counter man at the parts store - and he said to leave it at 180. Just wanted to get a second opinion - dont' want to create premature bearing wear if I tighten it too much.

*******************

How much in/out movement is there with the drive axle and bearing during suspension flexing and steering movements? Is the grease on the spline necessary to insure free movement - or is everything pretty much 'locked into place' after the axle nut is installed and tightened.

And speaking of the axle nut - if there is an allowance for the in/out movement - will setting the axle nut at 180 ft/lbs instead of 107 ft/lbs reduce the amount of allowed movement designed into the vehicle by the manufacturer?


I'm thinking that the in/out movement is basically non-existant - the axle position is locked into place when the axle nut is tightened - and that 180 would not make any difference vs the 107.

Appreciate any input.

Thanks -

You are torturing yourself over these issues, 180 torque, done. No axle movement in the bearing. Slight amount of grease between the seal and hub is ok to prevent water intrusion ( too much will prevent reinstallation of the seal), slight amount on the axles splines for ease of future disassembly is ok here.