[DeTomaso] Wheel bearing check

[Robert Stroj]

Hi Mike,

Thanks a lot for precise instructions!
Checked all 4 wheels and only little play I was able to detect was on rear passenger wheel.
Strange is that it had absolutely no play side to side (3/9 o’clock positions) but only small amount in vertical direction (12/6 o’clock).

Would this indicate a bearing wear or something else?

It can move only about 1mm measured at the tire; what is the acceptable range?

Thanks a lot, Robert 

> On Jun 28, 2019, at 8:53 AM, Mike Drew <MikeLDrew at aol.com> wrote:
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> Sent from my iPad
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>> On Jun 27, 2019, at 17:24, Jack DeRyke via DeTomaso <detomaso at server.detomasolist.com> wrote:
>> 
>>  The time-honored way to check rear wheel bearings is to remove the tub,
>>  and with a knowlegable person helping you, throw a haunch into the rear
>>  fender approximately above the center of the rear wheel cutout area, in
>>  line with the wheel center.
> 
>>>> Uh....no. That is the time-honored way to pound a big dent in your fender.  No reasonable person would ever check for a bad axle that way. Saying “Don’t do it so hard that you dent the fender” is crazy. How hard are you supposed to smash into the side of your car??? Who knows the answer to that question? The only way to know for sure is to do it too hard. And then you have a dented fender. 
> 
> All you have to do is gently jack the rear of the car so the rear wheels are off the ground. Grasp the tire at 3 and 9 o’clock and try to wiggle it in and out. There should be NO movement. Axle wear (despite how it feels and how people describe it, invariably the bearings are fine and instead it’s the axle that’s trashed) manifests itself with notable play accompanied by an audible clunking. A little play and clunking is bad, and should be dealt with in a reasonably timely manner. A lot of play can be catastrophic, and leads to this:
> 
> <image1.jpeg>
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> Most everything else Jack said is reasonably accurate. 
> 
> It’s worth mentioning that a tiny amount of play can be caused not by the axle/bearing interface, but rather by the lower shaft interface with the bearings in the lower part of the cast iron hub carrier. Those bearings can wear which can allow unwanted movement that mimics an axle going bad. Look for the source of the movement on the inside of the wheel, and also check for movement with your hands at 12 and 6 o’clock. If it moves both horizontally and vertically, it’s almost assuredly the axle. If it moves side to side but not up and down, it’s probably the upright/lower shaft bearings, not the axle. 
> 
> I am a staunch advocate of replacing the stock inner bearing with a double-row bearing, which spreads the load over a much greater portion of the axle. It’s not a perfect solution because part of the OD of the bearing is unsupported by the hub carrier. But it’s still better than the narrow single bearing, and costs virtually nothing more. 
> 
> Also, when pressing the hub carriers apart, support the brake rotor using a large piece of iron pipe.  If you only support part of the rotor in the press, the rotor can easily be shattered. I’ve seen it happen and it ain’t pretty.....
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> Mike
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