Checking Wheel Bearing Preload

Driley · 05-15-09, 08:02 AM

It has been a few weeks and about 300 miles since the rebuild of my front axle. I am going to drain and refill the diff and wanted to check the preload again. I will check for play using the 12 & 6 o'clock method but wanted to know if there was any way to check the preload without taking the drive flange + brake pads off.

I have been feeling the hubs after driving and they are only warm to the touch, never too hot to hold onto.

Just wanted to check to see if there was some fancy trick to verify the preload without disturbing the flange gasket.

Thanks,

Riley

Tech44 · 05-15-09, 11:20 AM

Well the easiest way to tell if there is play in the wheel bearing is the standard...lift lc or wheel off the ground and do what you mentioned. Check your 12 and 6 play. In the past I have used the standard gasket for the initial button up and then after about 300-500 miles I will check again and if I have been doing a lot of off roading I will do it once a year. The price of the gasket and the time it takes to check is worth it to me. May be excessive but to each their own. At this low mileage and low heat area the gasket should come right off. Once I have checked pre-load again I will use gasket seal and put it back together. You should not have to remove the brake pads to do this though if you are a person that goes by the book, then yes it is a good idea to get a true and absolute reading.

Hope it helps and good luck.

Driley · 05-15-09, 12:00 PM

I already have the front end lifted and have checked the 12 & 6 o'clock on both sides. No play at all. I have the brake pads off and have started removing the drive flange/plates. I just want to have both sides apart and spin the hubs around to make sure I did not set the preload too high.

The diff fluid still was honey color (same as new) with a slight green tint (like Beowulf mentioned prior).

Just piece of mind.

Thanks for the comments!

Riley

Driley · 05-15-09, 02:09 PM

Both sides preload is at ~12 lbs. per the pull scale and both feel very smooth.

One item of concern. The passenger side wheel bearing grease (Mobil 1 Synthetic) is still the same red color but the driver's side has a little purple tint. Does this mean that side got too hot? Does this merit a teardown and repack of the wheel bearings?

Both hubs turned nice and smooth and the gaskets came off clean.

Riley

azrider · 05-15-09, 06:26 PM

Why would you drain and refill your diff after only 300 miles?

Tech44 · 05-15-09, 07:25 PM

Well it sounds like you are already at the tear down stage and if the grease color is different on the wheel bearings it could be due to a few things...if you replaced with new I would be concerned about heat. Noting the preload of the wheel bearings on the prior install, it may have been too high. If you checked, cleaned and repacked the wheel bearings, you may not have cleaned them thorough enough. Also could have been from water...condensation, etc. I suspect you torqued the hub to the proper specs on the prior install but, who knows. I am sure others will have ideas as well. As far as draining the diff fluid again and replacing, unknown...I will be be doing the same thing with half trans fluid and half diff fluid but I will not go 300 miles. My lower trunion bearing was destroyed along with the oil seal, 1 wheel bearing and metal flake was everywhere. This will mostly ensure that any major debre that I was unable to clean out will come loose. If the pull scale reads what it should you are probably good but, I hear peace of mind.

Good luck

Driley · 05-15-09, 07:53 PM

Quote:

Originally Posted by azrider

Why would you drain and refill your diff after only 300 miles?

During the rebuild, I did not bother with trying to get the inside of the axle housing clean. I decided to just fill with cheap 80w90, drive for a while and drain and refill.

Riley

Driley · 05-15-09, 09:20 PM

Quote:

Originally Posted by Tech44

Well it sounds like you are already at the tear down stage and if the grease color is different on the wheel bearings it could be due to a few things...if you replaced with new I would be concerned about heat. Noting the preload of the wheel bearings on the prior install, it may have been too high. If you checked, cleaned and repacked the wheel bearings, you may not have cleaned them thorough enough. Also could have been from water...condensation, etc. I suspect you torqued the hub to the proper specs on the prior install but, who knows. I am sure others will have ideas as well. As far as draining the diff fluid again and replacing, unknown...I will be be doing the same thing with half trans fluid and half diff fluid but I will not go 300 miles. My lower trunion bearing was destroyed along with the oil seal, 1 wheel bearing and metal flake was everywhere. This will mostly ensure that any major debre that I was unable to clean out will come loose. If the pull scale reads what it should you are probably good but, I hear peace of mind.

Good luck

All bearings and grease were replaced with new during the rebuild.

I will just drive it for now and after a while order new gaskets and hub grease seal from cdan and repack everything (OCD).

I just do not know how it could have heated up. The preload was good and the hub feels very smooth. Who knows?

Riley

dkroth · 06-15-09, 11:15 AM

Quote:

Originally Posted by Driley

I have been feeling the hubs after driving and they are only warm to the touch, never too hot to hold onto.

Riley,

Are your hubs still warm after a drive?

I just finished up a knuckle rebuild on my truck. I've had three, 20 mile drives so far. At the end of all of them the hubs are warm to the touch. Again, not too hot that I can't leave my hand on there, but warmer than I expected.

Did yours cool off after a few hundred more miles?

I may pull the locking hubs and back the lock nuts off just a little to see if that makes a difference.

Driley · 06-15-09, 11:23 AM

Quote:

Originally Posted by dkroth

Riley,

Are your hubs still warm after a drive?

I just finished up a knuckle rebuild on my truck. I've had three, 20 mile drives so far. At the end of all of them the hubs are warm to the touch. Again, not too hot that I can't leave my hand on there, but warmer than I expected.

Did yours cool off after a few hundred more miles?

I may pull the locking hubs and back the lock nuts off just a little to see if that makes a difference.

My driver's side still gets a bit warmer than I expected it to be. I have driven ~ 800 miles since the knuckle rebuild and am planning to open up the driver's side and see how the grease looks. When I opened both sides at about 300 miles, the driver's side Mobil 1 grease had a slight purple tint to it (instead of the red color out of the can). If the grease looks the same, I will just leave it alone. If the grease looks or feels different, I will order up the required gaskets/seals and redo the wheel bearing pack/preload on that side.

Riley

RedTacoma · 06-15-09, 11:39 AM

Quote:

Originally Posted by Driley

It has been a few weeks and about 300 miles since the rebuild of my front axle. I am going to drain and refill the diff and wanted to check the preload again. I will check for play using the 12 & 6 o'clock method but wanted to know if there was any way to check the preload without taking the drive flange + brake pads off.

I have been feeling the hubs after driving and they are only warm to the touch, never too hot to hold onto.

Just wanted to check to see if there was some fancy trick to verify the preload without disturbing the flange gasket.

Thanks,

Riley

Sorry for Hijack but quick question.
To check for bearing play you need to remove brake pads and drive flange?
I had pads of and was was checking for play and got nothing so I was wondering if I should remove drive flange?

Driley · 06-15-09, 11:45 AM

Quote:

Originally Posted by RedTacoma

Sorry for Hijack but quick question.
To check for bearing play you need to remove brake pads and drive flange?
I had pads of and was was checking for play and got nothing so I was wondering if I should remove drive flange?

To check for play, you can leave the brake pads and drive flange on. To check preload, you need the remove the pads (so they are not dragging on the rotor) and drive flange (so you are not turning the other wheel).

Riley

RedTacoma · 06-15-09, 11:55 AM

Quote:

Originally Posted by Driley

To check for play, you can leave the brake pads and drive flange on. To check preload, you need the remove the pads (so they are not dragging on the rotor) and drive flange (so you are not turning the other wheel).

Riley

Thx, thats big help. Sorry for HiJack...

I need to start new thread then.

Tools R Us · 06-15-09, 12:30 PM

Just a data point, my front hubs run about 120-140F, rears about 110-120F, depending on how much the brakes have been used, ambient temp, etc.

Driley · 06-15-09, 12:34 PM

Quote:

Originally Posted by Tools R Us

Just a data point, my front hubs run about 120-140F, rears about 110-120F, depending on how much the brakes have been used, ambient temp, etc.

Thank you for the temp data!

I was more alarmed by the grease color change than the temp/feel of the hubs. I am pretty sure that no water got in there so it must be heat related.

I just need to get the time to jack her up and pull the drive flange.

Riley

Tools R Us · 06-15-09, 12:48 PM

Quote:

Originally Posted by Driley

...
I was more alarmed by the grease color change than the temp/feel of the hubs. I am pretty sure that no water got in there so it must be heat related.
...

Most good greases can take 200F+, so I doubt that it's heat related. Most color change is from contamination, like not cleaning all of the old grease out, some moly migrating from the bushing, birf area, etc. Most times not an issue as long as you have good preload and the temps are close side to side.

Driley · 06-15-09, 12:53 PM

Quote:

Originally Posted by Tools R Us

Most good greases can take 200F+, so I doubt that it's heat related. Most color change is from contamination, like not cleaning all of the old grease out, some moly migrating from the bushing, birf area, etc. Most times not an issue as long as you have good preload and the temps are close side to side.

Thanks again for the information. I cleaned the hub pretty well with mineral spirits during the rebuild (installed new rotors so I had the hub broken down completely). I guess I may have some contamination from the moly grease. If the grease is still intact and has not turned black I will just keep on driving.

Thanks again,

Riley

wxm · 06-15-09, 02:36 PM

Great we reach the conclusion that I like to hear because I really don't feel like to take it apart again.

KurtKuhn · 06-15-09, 05:30 PM

Quote:

Originally Posted by Driley

Both sides preload is at ~12 lbs. per the pull scale and both feel very smooth.

Is your new preload measurement the same as when you finished the rebuild?

-KK

Tenzig Norgay · 06-15-09, 05:54 PM

I've taken my front end apart several times after doing my rebuild, in my quest to solve my WOO WOO blues. I noticed purple amsoil had migrated from the birf area through the axle splines/c-clip, and then into the outer wheel bearing area. I heard this was common, and nothing to really worry about. Could this be what happened to you?

Driley · 06-16-09, 07:34 AM

Quote:

Originally Posted by KurtKuhn

Is your new preload measurement the same as when you finished the rebuild?

-KK

I set the preload at ~15 to 18 ft.lbs. (on a pull scale) originally and when I checked it after 300 miles it was consistently at ~12 ft.lbs. I just could not get it to stay below 10 ft.lbs. once I torqued the outer nut on. I would have the pull at 6 to 7 ft.lbs. then torque the outer to 43/47 ft.lbs. and it would always come out in the high teens. After reading suggestions that setting it a bit high originally was a common practice, I just went with it.

Riley

Driley · 06-16-09, 07:35 AM

Quote:

Originally Posted by Tenzig Norgay

I've taken my front end apart several times after doing my rebuild, in my quest to solve my WOO WOO blues. I noticed purple amsoil had migrated from the birf area through the axle splines/c-clip, and then into the outer wheel bearing area. I heard this was common, and nothing to really worry about. Could this be what happened to you?

I hope it is just common migration of moly grease into the wheel bearing area. I just need to get the time to open it up.

Riley

wxm · 06-16-09, 09:36 AM

Quote:

Originally Posted by Driley

I set the preload at ~15 to 18 ft.lbs. (on a pull scale) originally and when I checked it after 300 miles it was consistently at ~12 ft.lbs. I just could not get it to stay below 10 ft.lbs. once I torqued the outer nut on. I would have the pull at 6 to 7 ft.lbs. then torque the outer to 43/47 ft.lbs. and it would always come out in the high teens. After reading suggestions that setting it a bit high originally was a common practice, I just went with it.

Riley

I think the key to adjust the preload is the inner lock nut. The FSM calls for 48 in-lb after re-torque. As Riley pointed out, it is suggested to set it a bit higher so I went an extra 5-10 degree turn after torque it to 48 in-lb. My preload ended around 12-15 which is what I wanted.