Checking Wheel Bearings

[Romer]

I did my front axle a couple of months ago and just came back from Moab. I was thinking I should check my Wheel Bearings to make sure they are not loose. Is it as simple as jacking one wheel up and trying to rock it? I don't have any symptums that I can tell, so what would the symptums be for a loose wheel beaing?

 

[landtank]

I usually can feel the loose bearings in my feet, even if I'm a passenger. Jacking up the front axle and grabbing the tire at 12:00 and 6:00 o'clock and checking for play should do the trick.

 

[tarbe]

It would seem like the "best" way would be to remove the wheel and caliper, grab your fishing scale, and check the bearing pre-load.

That is how you determined proper pre-load when you put everything back together....ought to be the optimum way to check later on.

The method mentioned above will certainly tell you if a bearing is grossly loose. I'd like to know before then and I bet you would, too.

 

[Hayes]

Hey. This is just the topic I am looking for.

I'm 1/2 way through my first birf repack (I did one side yesterday, the other side today).

I'm certainly a newbie, and I couldn't figure out exactly how to check the preload. I followed the hub-nut torque proceedure, but I can't figure out what to do with the spring scale.

How exactly do you check the preload using the spring scale?

Any response is greatly appreciated, as I'm finishing the job today.

Thanks.

Hayes

 

[Hayes]

Don't mean to hijack this thread, but my questions are right on topic.

After reading some past threads, it sounds like I pull on a lug nut (with the caliper off) with the spring scale and measure the force required to spin the wheel. I assume the angle of pull needs to be at 90 degrees to the radius (from the hook to the axle)?

I followed the 48lb/ft spinx5 spinx5 loosen spin tighten outer nut at about 3 lb.

I've got no play whatsoever, but I suspect by preload will be higher than the spec 6-12 lbs--if the proceedure I described above is actually correct. I'm using Valvoline MP grease.

I'll head out the the garage shortly and actually take a measurement, then I'll report back.

Hayes

 

[e9999]

btw, isn't that the page in the manual where there is a typo from inlbs to ftlbs???

Robbies showed us a trick on how to set bearings at Moab by prestressing and then checking for side to side movement or something like that, but that was way too sophisticated for me and I don't quite remember what exactly what that was...

 

[tarbe]

You figured it out Hayes. Just apply the pull slowly and evenly so that when it breaks, you'll get a correct reading. If you increase the load too quickly, you get a false high reading.

 

[RavenTai]

Yes you pull 90° from a radius line drawn from the axis of the axle to the lug stud.

"I followed the 48lb/ft spinx5 spinx5 loosen spin tighten outer nut at about 3 lb."

When you say outer nut do you mean the jam nut? If so it gets tightened to 47 foot pounds.

My modified FSM procedure for the front:

1. With just the adjusting nut (inner nut) installed tighten to 43 foot pounds turn left and right at least 3 revolutions, it will be stiff.
2. Repeat step 1.
3. Loosen the nut to hand tight, do not turn.
4. Tighten the adjusting nut to 48 inch pounds ( 4 foot pounds ) turn left and right at least 3 revolutions. It should turn with less resistance now.
5. Repeat step 4.
6. check pre-load and adjust torque of adjusting nut as necessary to get in the range (IMO the top of the range is preferred, especially with new bearings)
7. back off adjusting nut about 1 flat (60 °) do not turn
8. Put in the lock washer and the Jam nut, tighten the jam nut against the lock washer and adjusting nut to 47 foot pounds. turn left and right at least 3 revolutions,
9. Check pre load same as step 6. If it is bad start over at step 1. and use more or less back off in step 7.If it is still good then bend one or more of the ears on the lock washer against the jam nut to prevent movement,
10. Check for play in the bearing, there should be none. It should turn smoothly with little noise
11. check for play every few K miles until about 20K


The reason for the back off in step 7. is that when you tighten the jam nut (outer nut) it takes up any play in the adjusting nut threads (inner nut) making the preload higher. Slightly backing off the adjusting nut makes up for this getting you back where you started after tightening the jam nut.

The rear is similar but has important differences


Tarbe, to check the preload you have to remove the wheel, brake pads and drive plate, that means dealing with cone washers and most likely you will need to have a new drive plate gasket on hand. You are right that it would be best but I think checking for play by grabbing top and bottom is good enough for a spot check.

 

[tarbe]

Right, the drive plate....don't want to be working against the front guts...that'll give you a really high false reading!!!

 

[Romer]

Ahhhhh, nice and tight, no play at all. Oops, didn't mean to hijack the thread. Wait a minute, its my thread! (lol)

Great discussion on preload. I didn't use a fishscale and most of the folks I talked to didn't. We used the torque, and back off by feel method.