Wheel Bearings et al

[Deathdeelr]

I'm in the midst of lifting the 880. I've got the right front done and am finishing the left front and hopefully the rear today. Everything is going surprisingly well; so well in fact that I'm expecting the bottom to drop out on me at any minute. Since I have the truck in the air I'm also tidying up some of the maintenance points like replacing the gear oil, greasing everything, etc. Since I've been reading about every thread I could find concerning the front axle and suspension, I realized I never put any grease in the wheel bearings. SO, grease gun in hand I discovered that at some point in the past they plugged the grease fitting hole in the wheel bearing retainers with rubber plugs rendering the wheel bearings ungreaseable. When I took the gun to the front driveshaft slip joint and u-joints I found there is also the tinyist bit of play in the pinion along with a slight fluid leak from the pinion seal. My questions are...

1. Should I be worried about any lack of lubrication with respect to the wheel bearings?
There's no play or noise in either side. The knuckle joints are tight. But then this leads me kind of into the next question:

2. Can I block the diff and put a quarter or half a turn on the pinion to take up the play?
I've never actually set up a ring and pinion but I know how and what's involved and I'm worried that if I mess around with the pinion nut or the preload I may end up rebuilding the axle myself. It's the old "well if the pinion bearings are bad I need to pull the diff which means I need to pull the axles which means while I'm in there I might as well change..." and on, and on...

Did I mention due to the weather my money tree hasn't blossomed yet?

[712edf]

This is I believe a Dana 44-FBJ axle. Guys who run them will tell you not only to grease the wheel bearings upon assembly, but every few months after that. That's a weak point on those axles/hubs. I personally prefer not to own one, because better fronts are out there.

I don't think tightening the pinion yoke nut is going to truly solve your problem there either.

Bucky

[Deathdeelr]

It is a 44FBJ. My brother told me a while ago that he had it rebuilt who knows how many years ago when he had the truck. I've had it about five years now and have never greased the wheel bearings. I've never had it apart either for that matter. I was into the left side today and same thing, rubber plug in the grease fitting hole.

If I tighten the pinion nut as a temporary fix will it affect the backlash or depth settings?

[Charles Talbert]

I'm not quite sure exactly where you are coming from with these questions. Kind of sounds like you just wish you had not come upon these issues. Of course not greasing will certainly lead to more serious issues, better off to go ahead and just address the issue and correct it before other trouble results if that is not already the case when you do look deeper. If you have ignored this for 5+ years, well.

As for trying to take loose motion out of a gear set by increasing the torque on the pinion nut, it ain't going to happen, you can wring the end off the shaft and nothing would change prior to pinion shaft breakage. Both pinion and carrier settings on DANA rear ends are set up with shims, once the shim pac is in place and the torque is set on the yoke nut, there will be no backing off of that setting if it was done correctly. Thus increasing the torque of the pinion nut will not change a thing as far as backlash of the gear set is concerned. Any experienced gear box mechanic will tell you that backlash will be evident when checking from the pinion end of the assembly as you are. Actual backlash measurements are taken from the ring gear during a set up, no accurate test can be made from the pinion yoke. My guess would be no problem exist at all with the diff set up based on what you have described. What you feel at the drive shaft yoke sounds perfectly normal.

[Deathdeelr]

With respect to the wheel bearings, not really ignored so much as ignorant but I guess at this point they're one and the same. I've decided to replace the rotors as they're pretty bad on the back side so bearings are going to be done as well and I'll install the correct grease fittings. Another project for another day.

Charles, I understand your answer about the backlash. That was part of my question. However I don't think I'm asking the correct question. I can actually move the yoke left to right and up and down and it has just enough play to notice. I think that play is in the bearing. When I twist the yoke clockwise and ccw that I believe is the shimmed backlash setting you're talking about. What I want to know is can I tighten up the bearing slop by tightening the pinion nut without affecting anything else or like you said am I just wrenching in the dark and am more likely to break it off without taking up any of the slop?

[Charles Talbert]

With respect to the wheel bearings, not really ignored so much as ignorant but I guess at this point they're one and the same. I've decided to replace the rotors as they're pretty bad on the back side so bearings are going to be done as well and I'll install the correct grease fittings. Another project for another day.

Charles, I understand your answer about the backlash. That was part of my question. However I don't think I'm asking the correct question. I can actually move the yoke left to right and up and down and it has just enough play to notice. I think that play is in the bearing. When I twist the yoke clockwise and ccw that I believe is the shimmed backlash setting you're talking about. What I want to know is can I tighten up the bearing slop by tightening the pinion nut without affecting anything else or like you said am I just wrenching in the dark and am more likely to break it off without taking up any of the slop?

OK, a good verification. Since you brought the situation better to the light, yes the pinion shaft bearing set up is loose. Several reasons could be in play. If the set up was done correct initially, the pinion shaft bearings are obviously on their way down, catastrophic failure will be the eventual result taking out the gear set and very possibly other carrier components as well.

The pinion depth is set to the correct position by shimming. With some DANA units a crush collar is used that actually crushes down as the pinion nut is torqued, they can only be used once sucessfully, and are not reusable when the set up is broken down for any reason. A new collar must be used with each set up. Not all use the crush collar, not sure if yours has the collar. As I mentioned, several factors could be in play. Assuming the set up was done correctly is covered in the above paragraph. If some part of the installation went lacking initially, such as a previously used collar being used a second time, thus being the cause for the set up torque not holding as it should. Possibly the pinion yoke lock-nut was re-used, (it always should be replaced as with the collar), a used nut very likely will not hold torque. Bearing preload is also critical, if too little preload was set into the assembly, it may feel good at the time, but would loosen quickly when put into service causing exactly what you are feeling. Many times this happens when a unit is built up with previously run bearings. Many builders try to re-use bearings, leaving the set up preload slightly loose thinking that is the thing to do since bearings have already been run in. The only way to do this right is to renew the bearings with every new set up, it's the only way not to cut corners and eliminate possible problem issues.

Your decision from this point forward is of course up to you. Here are the chances you take. The unknown is always the killer, you will never know exactly what is going on until the unit is pulled down for a visual inspection. If the bearings are already failing, catastrophy will be the end if you keep running, taking out everything in sight. If you tighten the pinion yoke nut to remove loose motion against already failing bearings, you will drastically speed up the failure. Remember, whatever the reason for this loose bearing set up is, it is already well into play and on the road to failure. There is always a reason, this doesn't just happen in a correctly done unit set up.

The only smart recommendation anyone can make at this time, and my best assessment based on your description; tear it down for a complete cleaning and inspection. Don't forget to check out spider gears and thrust washers. See for sure the reason behind the loose motion. If it isn't too far advanced, the gear set may be re-usable. When you check it out, it may be obvious this has gone on too long and caused abnormal wear patterns to form on gear teeth, etc. The best thing you can do is not look for short cuts when building, DANA parts are readily available, and are reasonably priced. Short cuts bite hard, even though in your case done by a previous owner, that may be exactly what you are experiencing right now.

[Deathdeelr]

Outstanding Charles. You are the man. I'll pull the cover and see what's what with the diff when I do the brakes instead of messing with the pinion. Until then she'll have to stay extremely local. Like in the driveway. I guess I'm going to be doing my first axle rebuild before long but I'd rather do it right than do it at all. Thanks again.

[Charles Talbert]

Outstanding Charles. You are the man. I'll pull the cover and see what's what with the diff when I do the brakes instead of messing with the pinion. Until then she'll have to stay extremely local. Like in the driveway. I guess I'm going to be doing my first axle rebuild before long but I'd rather do it right than do it at all. Thanks again.

Well, being the man really doesn't fit the bill here. I'm just trying to see your issue as best I can in an effort to offer a valid opinion that will help you figure it all out. Good luck, hopefully I've hit on some valid info for you. If I can help further once you get into it, just ask.

You may already know this, I failed to mention that a housing expander is required in order to pull the carrier out of and install it into DANA housings. The housing must expand about .020" horizonally to allow for removal as the carrier is a shimmed interference fit. This sets horizonal gear set adjustment and carrier bearing preload. These are quite expensive tools, I would check automotive tool rental outlets to see if one is available for rent in your area. I believe ours cost around $500 when new. You could fabricate one without too much problem, I built my first one and used it several years before finally purchasing the genuine article.