I have a 2001 F250 4x4. I noticed a noise coming from the front left hub. Since there was a slight play in the wheel bearing I decided to replace the full assembly. I have read some of the related articles on this site, but I have some questions. Any input would be appreciated:

1. The hub bearing assembly comes with a needle bearing where the front axle goes through. Even with the new hub bearing assembly the axle shaft is loose in the hub assembly (that is before inserting the hub lock). Is there supposed to be some play? The axle shaft is only activated in the 4x4.

2. The Raysbestos/Federal Mogul hub bearing assembly has new needle bearings. These needles are loose and are kept in place during shipping with a plastic cap. Since the shaft assembly is somewhat loose in the needle bearing, would there be a chance that the needles may come off? The OEM needles in the bearing assembly do not come off.

3. My knuckle seal and shaft seal appear to be OK. However, there is a ring (looks like a dust seal) that it is loose. Is this a concern? I sure do not want to pull the axle shaft out to replace this seal.

Any input would be appreciated greatly!

Leon

 

I have only ever dealt with factory ford hub/bearing assemblies in the past, as I worked at a dealership, but these needles that will come out of the spindle bearing doesn't sound very good to me. I don't like the idea of that. I may be wrong, but it sounds like a cheap bearing. There shouldn't be very much play in the spindle bearing area with the shaft going through it, but the shaft will move around some at the end if there is no hub-lock in it. If there is play in the spindle bearing area, check the area on the axle shaft that previously ran in the old spindle bearing. It should be level along the shaft across this area. If it is worn in much at all, it will cause the spindle bearing to fail rather quickly, and also put abnormal stress on the hub-lock and everything else because the axle shaft will not be properly supported. If the old spindle bearing is very dry, or rusty, that is what usually causes axle shaft wear. If the inside of the old hub assy. is rusty, or very dirty, or has any signs of water intrusion, the main knuckle seal is usually to blame, or the yellow o-ring around the hub/bearing assy. These seals failing is usually related to the auto-4x4 vacuum system helping to pull moisture into the housing...if your truck has this feature...When your're all done with the repair, even if yours is a manual 4x4, use a hand vacuum pump connected to the vacuum port on top of the knuckle, pull about 12-15 in.of vacuum, [this will take some time to pump that much] and make sure it holds. This is always a good thing to do every oil change, or every other, to make sure the knuckles are always sealed. If they're not holding vacuum, you'll get moisture for sure in the knuckles, leading to EVERYTHING in there failing. This is the most common cause for bearing failures in this area. Hope this helps. That rubber ring on the axle shaft is a dust seal to prevent dirt from getting into the axle tube, and contaminating the inner axle shaft seals. They are often torn and loose, and in time will contribute to axle seal failure.

 

Kenny:

Thanks for your advice. I will be checking today with few 4x4 shops in the area to find out if the loose needle bearings are acceptable. You are right that the needle area from the hub bearing assembly was rusty but there was grease around it. The hub lock had really fallen apart and it was difficult to turn the **** from Auto to Manual.

I looked at the shaft area where it goes into the needle bearing and I do not see much wear. Since there is no pre-load on the needle bearing - just the thrust washers holding it in place - I do not see how it can be tight.

The rust likely came from a broken vacuum hose where it is connected to the knuckle.

How difficult is it to pull the axle out once the hub bearing assembly is out? According to the shop manual the knuckle seal needs to be pushed out and then do you just pull the axle out? It is only held by a snap ring at the differential housing? Won't I need to drain the fluid from the differential? The shop manual is not very clear on this issue.

Thanks
Leon

 

When I R&R'd my inner spindle bearings (needle bearings) there was a decent amount of play between the bearings and the axle stub. I'd say somewhere between .010" and .020" or even more.

Those "loose" needles do NOT sound good. They are not supposed to be like that.

If you want to use those complete unit bearings, replace the needles with a Nationl/Federal-Mogul B-2110 bearing. They are less than $15 at Napa I believe.

 

Thanks for your post. The wheel bearing assembly that I am referring to is brand new made by Federal Mogul / Raysbestos. The unit came with a cap in the needle bearing opening obviously to keep the needles from coming off during shipping.

Given that when installed this bearing is not pre-loaded and that there is certain amount of play, I would think that these needles can come off easily. Do you or anyone has had any experience with this?

 

Are you sure they fall out if you remove the cap? Or is it just there to keep dirt/dust out of them?

Can you find a number on the needle bearing race and post that?

The axle might flop around a bit inside, but I doubt it's enough to actually have a needle fall out.

 

I thought the same thing when I initially open the box - that is that the red cap in the needle bearing opening was there to keep dirt from falling in. At some point I notice that one of the needles fell off - upon further investigation I confirmed that they are loose and held together by grease.

I do not have the part in front of me since it is at home - I do not recall any parts numbers stamped on the race but I may be wrong. Should I return it and purchase an OEM part?

 

Can you post a picture?

 

I will be glad to do so but since I will be out of town until Sunday night I will not be able to do it until then.

 

I spent my lunch hour going to a number of 4x4 shops. Opinions did differ but here is the conclusion:

Indeed the needles in the needle bearing are loose and could come off. This is true with the FORD factory hub assembly.

In regards to the play between the axle and the needle bearing, a new axle and new needle bearing has almost no play. Mine has a lot of play but this is acceptable since the whole axle has a lot of play.

The ring of the knuckle seal is very common to come loose. No replacement of the seal assembly is required just because of this.

The only thing retaining the axle in place is the knuckle seal (after the hub bearing assebly has been removed). These seals are very tight and difficult to remove. Suggested way to remove it is by placing a long bar between the u-joing and the diffential tube housing end and pushing the axle with the seal outwards. Although differential fluid will not come out since there is a seal half way in the tube of the differential, some will seep past the seal once the axle is out. This will result in oil coming out after the assemply is completed.

 

I replaced my knuckle seal a few months ago because it was destroyed for the most part and I had a bunch of play in my axle/u joints and once installed it was back to normal. Nothing seeped out of my tube at all.

I would do what was suggested above and go to NAPA and get a new bearing for less thant 15 bucks and replace it and be done with it. Its a pretty cheap way to figure out what exactly is going on.

 

Thanks. It is good to know that the oil seppage may not occur. I probably would feel more comfortable doing what was suggested although I just changed the gear oil in the differential with synthetic few months ago.

If I understood your posting correctly you replaced only the knuckle seal and this took care of the excessive play? If there was too much play on the needle bearing, this will eventually wear out the seal.

Anyway, my needle bearing is new and it came with the wheel bearing assembly. The wheel bearing itself was little loose so I decide the replace the whole unit. Beside some moisture had gotten in the vacuumm area and there was some corrosion.

 

I had my whole bearing replaced at a shop. They forgot to put the yellow o-ring on and installed a thrust washer in the wrong place so the knuckle seal was slowly being eaten away over time. I have a video that shows the excessive play in mine and will link to my posting when I find it.

100_0294.flv video by triskit16 - Photobucket

 

Ok. Now I see what happened. Some of the "professionals" I spoke to in person, scared the hell out of me.....no wonder that they actually messed up yours....even the shop foreman at the local Ford dealership did not know much about it....

Despite the number of folks that I spoke to, no one could tell me for sure what play is acceptable between the needle bearing and axle shaft. Most of them seem to agree that there should be a play - I am assuming it all depends on how much you use your 4x4. I will put mine together and if I have problems I know what to do next: replace the outer axle shaft (you do not need to replace the entire axle shaft) and install new knuckle seal and dust seal on the differential tube.

 

Needle bearings, in general, come "cageless" or "caged." Some cageless needle bearings don't even come with the plastic sleeve, and the needles are only held in place with heavy bearing grease.

Hmmm ... I would have thought that the differential seal was where the axle tube meets the differential. Nevertheless, I've had the axle out of my truck for days, and when I went to reassemble, and cleaned out the axle tube, I found no seepage inside the tube.

Doesn't it seem odd that play between the axle end and the needle bearing is acceptable? Shouldn't any bearing-shaft assy be very snug? Otherwise there would be a bushing instead of a bearing .... like the clutch pilot bearing in the old Ford V8's? Maybe not. Did you notice if the old needle bearing in the bearing/hub unit you replaced was bad? And was wearing down the axle shaft end?

Good luck.