Rear Wheel Bearing Replacement.

Discussion in 'Workshop Forum' started by lookforjoe, Nov 16, 2019.

  1. lookforjoe

    lookforjoe True Classic

    Picking up from this thread. Bearings are 37x37x72mm. You can use Fiat 500 front wheel bearings.

    I had to redo one rear wheel bearing from 2015, and replace the other side original (137K miles)

    Fiat diagram. Plate (#5) is actually between 1 & 2, since it installs from the backside of the hub & sits against the back of the inner bearing seat. 3 & 7 are identical rubber lip seals that are stretched over the ridge on #1 stub shaft, and the inner ridge on #8 hub

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    I already had the control arms off the car for the K24 work. I did not remove the spindle from the control arm to do this work. Little fiddly doing the press work, but not that bad. I don't want to deal with the balljoints at this point, so I'm not touching them & risking damage.

    So, remove either the entire arm, or follow the manual & remove just the spindle, as you prefer.

    With the brakes removed, locate a suitable press tool / old socket that will fit inside (pass through) the inner bearing race - to use to press out the hub

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    I used a three-arm puller to press out the hubs - make sure puller is centered as possible, so you don't hurt yourself. Applying force with an uneven setup can make the puller arms fly off the spindle(!)

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    The back plate ear is a different offset than the caliper ears, so I added a shim to get the puller arms even

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    Use your favorite impact to zip the hub off

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    When you do this, the outer inner race may stay stuck on the hub shaft. If it does (one of mine did), I found the easiest way to remove it is to cut diagonally with a cutting disc going most of the way through to the center, then whack slot with a cold chisel to split it open. You don't want to cut all the way through the race or you will likely mar/damage the hub shaft.

    With that out the way, unstake the retaining ring

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    Then remove it with the tool (I bought mine from MWB)

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    They can be really tight - I used a 3/4 long breaker bar

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    having multiple vices is not a bad thing :)

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    that will expose the bearing

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    Find another socket or press tool that will fit over the bearing, but sit inside the rear dust seal plate (#5)

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    Use the three jaw puller to press the bearing out from the rear. Spindle clamped in vice.

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    and out

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    clean out any debris, clean lock ring threads, I put a little grease in the spindle cup where the bearing will be inserted. Inner seat and dust seal seat visible in this pic

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    Bearing must be installed in spindle first, then hub second. Outer ridge of outer bearing race needs to take the load when bearing is pressed, and inner bearing race ridge when hub is pressed.

    Pics here are not great, I was doing this outside in the dark at this point. Press lives on the backside of my garage. Control arm is set behind the press for this operation, the way I chose to do it. Plate & spacer on top, to make sure load is placed on the spindle. Bearing was tapped into opening of spindle prior to putting in the press, to make sure it is started square to opening. Old bearing is placed under to push new in place. If you do this with only the spindle, then the new bearing and spindle would likely be reversed in the press (bearing on top)
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    make sure press tool (old bearing) does not ride against the threads for the lock ring

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    You will feel when the bearing is seated.

    After that, install the lock ring with some nevr-seize, and stake

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    Install new dust/grease seal on hub ridge

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    Press hub into spindle, using an old inner race to press only on the new inner race

    Pic taken after the fact, hub is already seated here
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    Control arm tucked behind press again here. Press until no movement is felt. Backside of hub will be clear of spindle outer ridge.

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    That's it. Sorry aboout poor press pics.

    CV bolts - 31ft/lb
    Axle nut - 159 ft/lb
     
    Last edited: Nov 19, 2019
  2. Nice documentation. I've had much practice at replacing X wheel bearings. When the cars first came out, there was a problem with the bearing seals. I had to replace all four by ~20K. That was actually considered good back then as many bearings went bad on the sea trip and dealers were replacing bearings on cars with no mileage on them. The 74 cars did not originally come with the outer dust seals but I decided to try installing one last year when I had to replace a rear bearing. It seemed to go together OK although I found that depending on the specific bearing construction, it may or may not help. I found that some bearings have their integral seals tied to the outer race, and some to the inner race so the area benefiting from additional sealing can be in different places.
     
  3. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Thanks for doing the great write up Huss. ;)
     
  4. Cratecruncher

    Cratecruncher True Classic

    Location:
    Austin
    Excellent write up on a chore many will end up doing if they own their car long enough. It's so much easier to form a plan when you have a visual understanding of what is involved.
    Digging around on the MWB site I noticed the 4 speed cars use a 45mm bearing and the 5 speeds use 50mm so all the parts are different starting in '79.
     
    Last edited: Nov 19, 2019
  5. Dr.Jeff

    Dr.Jeff True Classic

    Location:
    Sin City
    Adding to what "Cratecruncher" said about bearing sizes. I don't recall hearing before that the new 500 front bearings are the same as the 5-speed X's (which by the way are the same front and rear I believe), so thanks for posting that bit of info. It's good to know; although the bearings are available for the X, the supply seems to fluctuate and I've noticed the quality also varies. So the newer 500 parts might be more accessible and/or better quality...or not, we'll see. But good to know the option existes. Makes sense they would fit as the rotors and other parts also fit.
     
  6. myronx19

    myronx19 True Classic

    Location:
    Toronto, ON Canada
    - ha! or NOT! (at least the rears on the 500, they fail very quickly).

    5 spd X1/9 bearings are different front and rear (4spd cars are the same IIRC), and apparently the X1/9 rears are the same size as the 500 Abarth front bearings (and according to this thread, 500 front bearings are all the same size (500 Pop/Lounge/Abarth).

    I found some NOS SKF rear bearings. I put some aftermarket ones in there, but there is measurable play in them that is enough to affect the brake pad parallelism in the brackets/relative to the rotor.
     
    Last edited: Nov 20, 2019
    Dr.Jeff likes this.

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