1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Rear Axle Spindle Wear

Discussion in '80-Series Tech' started by Sage, Jul 8, 2003.

  1. Sage

    Sage

    Messages:
    9
    Likes Received:
    0
    Joined:
    Jul 8, 2003
    Last weekend I disassembled the USDS rear hub on the unmodified “soccer mom” ’93 I bought about four months ago at 145K (FF, ABS, F/R diff locks). I recently serviced the other three hubs and hoped this would be a routine seal replacement and repack job. The first hint of trouble came when I pulled the wheel and discovered about a millimeter of axial play in the bearings. The e-brake shoes and everything else inside the rotor were oily, indicating that both hub seals had failed on that side. After removing the lock screws I noted that I could tighten the hub nut a little more than half a turn before feeling any resistance. I suppose we could call that “negative preload”. It’s anyone’s guess how long it had been that way.

    Disassembly of the hub showed that the inner races of both bearings had been spinning on the axle for a long time, but most of the damage was at the outer bearing. As I wiped the gear oil off of the spindle (no grease, only diff oil in the hub and bearings) I could feel the groove through the rag where the inner race of the outer bearing had worn into the underside of the axle spindle :eek: . The spindle shaft measured 45.20mm diameter in an unworn area and 44.94mm in the area of greatest wear. The 0.26mm (.010”) difference is entirely on the weight-bearing lower side of the spindle. Though it may sound small, 10 mils of wear on the radius creates a BIG step.

    When I serviced the front hubs a couple of months ago, the knuckle spindles showed similar wear patterns but the steps measured only 3-4 mils. I may have over-reacted, but I replaced both knuckle spindles (and the front wheel bearings) because I was concerned about the amount of bearing wobble that was possible with 3-4 mils of wear. As a result, I now have one of the few 80’s with the new roller bearing knuckle spindles 8). The front’s were easy because the spindles just bolt on. Now I have to decide what to do about the rear, and I could use some advice.

    Unless I’m missing something, the rear axle spindles are an integral part of the axle housing, which my local Toyota dealer lists at $1016. I’ve also checked the local junk yards without success. So here are my questions:

    1) Do I have any reasonable alternatives to replacing the entire axle housing? Welding and sleeves come to mind, but they leave almost as quickly. Does anyone know of a fix for this problem?

    2) What is the worst that might happen if I put everything back together, preloaded the bearing properly and pretended that I didn’t notice? Most people never would have repacked the hub in the first place, right? (Suppose I’m going on a 1000 mile trip soon, do I really need to fix this first?)

    3) Let’s say I bite the bullet and install a new axle housing. Other than a lot of work, is there anything about swapping my differential into a new axle that requires more than ordinary skill and equipment? (Toyota didn’t even include the FF axle in the ’93 FSM, so it’s not much help. :()

    Thanks,

    Sage
     
  2. cruiserdan

    cruiserdan SupportingVendor Emeritus Supporting Vendor Moderator

    Messages:
    20,603
    Likes Received:
    2,980
    Joined:
    Mar 27, 2003
    Location:
    Surrounded by Cruisers from all over the world
    Sage,

    You are correct, you will need to get a complete housing to get the "spindle". As far as welding it, I don't know. You DO NOT have to have a diff-lock housing to replace it with. You can use a non-lock housing by making a radius cut in the diff mounting sufface at the 9 o'clock position using the diff carrier gasket as a template. The housing swap is straight forward. Just pop the axles and hubs and brakes and diff and then stick them in the new housing. I don't know if you would be able to get just the housing from a junk yard. Usually they want to sell the hole assembly. A smart shopper could get a new housing for less than 800 bucks I imagine. If you need assistance in obtaining a new housing, please feel free to PM me and I would be glad to assist you.

    Good luck, Dan.
     
  3. semlin

    semlin rocker

    Messages:
    5,209
    Media:
    1
    Likes Received:
    322
    Joined:
    Mar 27, 2003
    Location:
    north of 49
    yikes, time to do the rear seals everyone!
     
  4. Sage

    Sage

    Messages:
    9
    Likes Received:
    0
    Joined:
    Jul 8, 2003
    Thanks for the information.

    There are a couple of unanswered question in this that should be of general interest as our 80s continue to log the miles and as more of us do our own hub inspections and service. The case I describe above is something of an anomaly (I hope) because it resulted from “gross mechanical misconduct” on the part of a PO or, more likely, the local dealership. So, admittedly, it represents an extreme case of spindle wear at .010”. But, if this amount of wear is excessive and requires replacement of the axle housing, what is an acceptable level of wear?

    As a point of reference, I rebuilt the other end of the same axle a few weeks ago. It had normally preloaded wheel bearings, but still showed about .005” of groove depth on the underside of the spindle at the outer wheel bearing. Is a 5 mil groove sufficient to require spindle replacement?

    My second question concerns the failure mechanism. Ultimately, something will fail when spindle wear becomes excessive. What fails, and how? Pairs of tapered roller bearings obviously have some limit to the amount of misalignment they can tolerate. Does axle spindle wear eventually lead to wheel bearing failure even with proper lubrication and preload, or does something else happen first? Rapid destruction of the seals would be another possibility, but I’m only guessing.

    This forum, and others, have devoted a lot of attention to the care and feeding of knuckle and axle seals and bearings, but I can find very little practical information about spindles, despite the fact that these seem to be the primary “non-replaceable” or at least non-disposable” part of the system that eventually wears out. It seems like this would be an even greater concern for those running oversize tires. Without a working "rule of thumb" for spindle wear, how can we do a meaningful inspection when we repack a hub? Since the wear is always on the underside of the spindle, I also wonder how often it goes unnoticed.

    Sage
     
  5. Rich

    Rich

    Messages:
    1,805
    Likes Received:
    3
    Joined:
    Jun 16, 2003
    Sage,

    Firstly, the spindle should not wear significantly. All the wear should be limited to bearings and seals. If the spindle is wearing, then the bearings are moving on the spindle.

    Anyway, your existing axle is not necessarily a lost cause. As long as you can mount new bearings in alignment, in a manner that the races will not spin on the spindle, you should be ok.

    To deal with your current problem of mounting new bearings on a worn spindle, look at http://www.loctite.com/catalog/product.html?ProductLine=620.

    It is designed to solve your problem! Contact their technical support for more info.

    Rich
     
  6. Rich

    Rich

    Messages:
    1,805
    Likes Received:
    3
    Joined:
    Jun 16, 2003