The next logical step after removing the drawn cup bearing... is to install a new one.


At first glance, this would seem easy enough, because access to the inside end of the unit bearing assembly (on the 4 bolt mounting side) doesn't require any long socket or special tool to reach through the axle bore in order to press a new one in place. Heck, there is enough access to use a 2x4. But that is only at first glance.


These drawn cup bearings, especially full complement ones without internal cages to separate the needles, are kind of delicate. The needles can be knocked askew, where all of them drift together a very tiny bit at an angle, like a row of dominos, only dominos that are all touching each other instead of standing apart. Now imagine flicking this row of dominos over, but just when they start tilting to fall, stopping them before they tilt noticeably.


Substituting these metaphorical dominos for needle bearing rollers captured inside a cylindrical drawn cup, when these rollers are not strictly perpendicular, but have just started to cant diagonally even a tiny bit, they can become "locked" into place. The act of installing a bearing can skew the rollers. Once locked, the axle shaft can skid on the rollers, which can wear flat spots on the rollers, making them even less likely to actually roll. So great pains must be taken not to dent the drawn cup and end up skewing or locking the rollers.


The tooling needed to protect the edge of the drawn cup (the part people beat on to press the bearing in place... or the part that I used a hydraulic press to force out of the old unit bearing) should have certain features to keep the profile of the drawn cup in tact. The crown of the drawn cup is where the rolling axis is of each of the tiny roller bearings. To protect that crown, the press tooling should have a 15 degree back angle that slopes downward toward the outer circumference of the drawn cup.


The tooling should also have a pilot post that is .003" less than the axle shaft diameter, to help support the needles while the bearing is pressed into place. The pilot post should extend the length of the bearing being pressed, less .031". The pressing cap of the tool (that has the 15 degree back angle surface), should be about .015" less than the housing bore that the bearing is pressed into. The bearing should be considered seated when recessed about .008".


So, on the one hand, I can get these bearings at Rock Auto all day for $2.63. On the other hand, where am I going to find the correct tool that presses the new needle bearing into the unit bearing, with the assurance of a proper installation?

 

Even though I got lucky just pressing these Torrington type bearings for years with just squared off shafting/push tools on Gear boxes Etc.In the future I will machine a better fitting push tool,Excellent info.

 

Well, I picked up some new seals, and took my hub bearing off, but not before implementing a simple method for lubricating that Torrington bearing without disassembling the hub or even the rotor. I'm glad that I pulled off the hub bearing assembly so that the efficacy of the short cut lubrication method could be evaluated. It works! More on that later, perhaps in a separate post/thread.


In the meantime, this thread is about squeaking... and even with the hub bearing removed entirely, I still have the squeak. So it isn't the bearing. Any of them. Not the big twin tapered roller bearing inside the hub, nor the little Torrington bearing that uses the axle shaft for an inner raceway. No bearings installed at all, and yet there is still a squeak.

It looks like the knuckle seal is squeaking. This is kind of what I suspected all along, because I had already greased both bearings. But the area I thought was squeaking was inside the axle tube, perhaps the broken dust seal. But now, I think it is the knuckle seal.

Rikster-7700, get back in this thread, because you nailed it early on.

Who has had a knuckle seal squeak? What did you do about it? I have manual shift 4x4, so I don't care about vacuum. But I do need to figure out this squeak.

 

Another update (and call for experience / ideas / help?!):

I don't think the squeak is the knuckle seal either. I think it is either the dust seal, or the internal oil seal. The squeak is on both sides. I can rotate the opposite axle and get the same fingernails on the chalkboard squeak. I really can't tell exactly what component it could be, and it hasn't been for lack of trying:





In my experience, Chassis Ears are more theater than diagnostically definitive, but just so you know, I'm trying every tool in the shed to figure out why the axle is squeaking. Or rather, where it is squeaking from.

Surely I'm not the only one who has heard these squeaks without a bearing involved to point to?

 

No squeaking at all when turning the front drive shaft by hand. Both axles rotate just the same, just 4.88 times less than the driveshaft is turning, but no squeaking.

Yet, when turning by the axle shaft, the squeak comes back with a fierce vengeance.

 

I've been following this thread because I have the same squeak. After listening to it for a couple weeks I decided to investigate. The first thing I did was turn the axle shaft by hand and that's when I realized it was locked, which was probably due to a previous attempt to find a vacuum leak (another story). After unlocking, the squeak went away and so did the very slight grinding noise I was chasing. So, now those two noises are cured (when in 2wd), but if I spin the axle shaft FORWARD by hand I still have the squeak. I do not have the squeak in reverse. I'm wondering if the squeak started due to driving for a couple/few weeks with the hub locked.

 

I found the squeak. Or at least, I eliminated the squeak.

It turned out to be on the opposite end of the axle. I hadn't planned on breaking the other side down, as the scope of this project was limited to only replacing an ABS sensor on one side only, that set codes, failed PID monitoring, and read open loop on a DVOM when I tested it. Replacing the one sensor had now turned into a full blown front end job, because of a screeching squeak.

It sure sounding like it was coming from inside the axle housing, yet it also sounded like it was coming from the knuckle I was working on. Based on where the sound SEEMED to be coming from, it didn't seem possible that it could be coming from further away. But it was. Once I removed the wheel bearing on the opposite end, I was able to rotate the axle shaft without any squealing squeaks.

So that solved the noise, and isolated the area where it was emanating from. But it hasn't solved which component was responsible for actually producing the sound. Was it the stub axle? The Torrington bearing? The knuckle seal? At this point, I'm going with the metal in the knuckle seal, because I did detect a small amount of metal shavings in the knuckle bore once the bearing was removed... and the shavings do not appear to have come from the Torrington bearing, because both the needles and the drawn cup appear in tact: (grease cleaned off to aid inspection of the bearing for wear marks).





Has anyone else reading ever experienced a knuckle seal squeal?

 

I think the lube is causing a bit more drag, I've had seal make a slight squeak, it was the secondary lip, it's too much of a bitch to lube the seal unless your pulling that shaft and greasing on the reinstall

 

I agree that adding grease through the ABS hole can cause more drag. Although exactly how much more is hard to measure by feel, if only a little bit more. And if only a little bit more, the additional drag is negligible when compared to the forces that turn the wheels, which easily overcome the added resistance to rolling.

However, more drag means more friction, and more friction means more heat, and thus the very purpose for which we are lubricating the bearings (to reduce frictional wear and keep them cooler) is somewhat defeated by the very measure we are taking to protect the bearing. It's like fighting cancer with cancer. Striving to do better, we often mar what is well.

Yet... our bearings AREN'T well when left alone. Mine were clearly dry, and in need of grease. Fortunately, I caught them in time, as they were not visibly worn, nor was the axle shaft they were riding on. The cone bearings inside the unit were dryish as well, although not completely. There was evidence of the old original grease oozing out evenly around the big bearing perimeter seal, and this was prior to my filling the bearing with new grease... so that tells me that filling with a lower viscosity oil (instead of grease) would likely end up escaping out of that perimeter seal much sooner than a grease would.

So there was a conundrum... to grease or not to grease. That is the question. Whether 'tis nobler to add grease, and run the risk of increasing the bearing operating temperature due to the heat from friction generated by the viscous grease? Or nobler not to grease, and run the virtual certainty of the bearings going bye bye in 60K miles or less. Field experience, widely reported on this forum, spanning over a decade of time, strongly suggests that greasing is the better idea.

But what isn't talked about much is greasing the knuckle seal. I do think that was the source of my squeak, but am not certain. The new knuckle seals I installed came pre loaded from Ford with grease... a dark yellow gooey substance that I could see peaking out around the perimeter of the seals. It might be a good idea to try and regrease the knuckle seals with a needle tip shot through the back side of the knuckle. The caveat is, exposed grease attracts exposed dirt, and dirt that becomes entrained in the grease becomes a grinding paste working against the very seal the shot of grease was intended to prolong the life of.

I don't know if this is a lose lose situation, or one of those it's all in how you look at it scenarios... glass half empty, or glass half full. All I know is, there is a lot of room in the glass for improvement.

 

So I'm not a machinist but was wondering if the fit on this is loose enough that a night in the freezer would allow for installing it with good ole shade tree methods without damage? Can't see the average DIY'r with an install tool with measurements that specific.


Glad you took the time to bring the specifics to our attention. Thanks,