SLEEPER 86

Cleaned up my bearing caps and found this. This is the drivers side cap. The passenger side is much better. I will post pics of the housing side too.

sofakingdom

iTrader: (1)

Well, post a pic and maybe we can help...

I did have to do an aluminum-case Dana 44 a few weeks ago where the driver's side bearing had spun in the housing. (the DS is always the one that wipes out first; the gears push the carrier toward that side, and away from the pass side, thus making the DS see many times as much load as the PS) The housing wasn't too terribly trashed, so it was possible to remove a couple of .001"s from the surfaces of the cap, and clean up its bore with sandpaper, going slowly and trial fitting it until it fit tight to the bearing like the PS still did. The car owner is very happy that the whole rear didn't have to be replaced.

SLEEPER 86

Pic 1

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Pic 2

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Pic 3

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Pic4

sofakingdom

iTrader: (1)

Doesn't look too bad really... measure the depth of bearing witness mark compared to the untouched machined surface right next to it, and go from there.

SLEEPER 86

Not sure I follow, what is the witness mark? If you're referring to the two holes in the surface, the larger one is just about .100 deep and. 089 across. The smaller one is about half that.
If you're talking about the polished area where the bearing spun, what would be a good way to measure that?

big gear head

Put the cap on and torque the bolts. Measure the bore where the bearing spun. Measure the diameter of a good bearing race. They should be the same size or the bore should be about 1/2 thousandth smaller. If the bore is only a few thousandths larger then you can do what sofa said and use it again. If it's much larger than that then you might need to look for another housing.

sofakingdom

iTrader: (1)

Yes, that's what I mean; the mark the bearing left.

You can use a bore gauge, a feeler gauge next to the "step", maybe a caliper with the piece that comes out the end but that's not real reliable that close to zero.

SLEEPER 86

Ok, I only have a digital micrometer, not a bore gauge, but I get .005 smaller than the bearing race. Does that sound right? I can't really measure the axle tube side of the bore which is slightly more worn than the carrier side. I have the T/A stud kit torqued to 50 lbs with oil per their recommendation.

sofakingdom

iTrader: (1)

No, doesn't sound right... that would imply that the wear had built up about .007" of metal on the housing. Doesn't pass the smell test.

SLEEPER 86

Didn't think so, I did repeat the measurement several times in a few different spots in the bore. Guess I'd better hunt down a bore gauge.

sofakingdom

iTrader: (1)

Is there enough of a "step" between the worn and the unworn areas, to catch your fingernail on?

http://www.use-enco.com/CGI/INSRIT?P...PMPXNO=5507081

big gear head

Get a machinest to measure it for you, or borrow some telescoping gauges and a 2 to 3 inch micrometer and measure it. I think that bearing race is about 2.875 inches, so the bore should be about 2.874 to 2.8745 inches.

SLEEPER 86

Sofa, definitely not a ridge big enough to catch my nail. If I recall, that would be about .030 or more.

BGH, I had a heck of a time finding a torque wrench that reads left handed (didn't know mine wouldn't) around here. Wish me luck on the bore mic!

SLEEPER 86

Best i can measure is 2.895 on the race and between 2.888 in the bore and 2.8885 on the carrier side edge. I measured both races and they are within .0005. I repeated this several times. Hmmm... I wonder if my caliper is off scale on the o.d. side?

SLEEPER 86

Autozone and Ratech list Timken set 47 which I have as 2.891 outside diameter. I measured 2.895. If my caliper is off by. 004 on the outside, wouldn't it stand to reason that it would be off the same amount on the inside? That would be very close to the .007 difference I am coming up with.

sofakingdom

iTrader: (1)

If you use the same caliper to measure both things, then however far off the caliper is, it will be off the same amount and direction on both. Not, large on one, and small on the other. Unless of course the jaws are damged, which .004" of damage to a caliper would be HUGE. It would look like it got hit by a falling rock or something.

So, no; instrument error alone doesn't account for the discrepancy.

However, if I had a caliper that's .004" off, I'd throw it in the trash and buy another. But that's not the issue right now.

All you're really looking for, is how much the place where the bearing goes, has changed. You can be fairly certain that the bore is now larger than it used to be, since metal doesn't wear onto a surface in that situation, only off; the question then is, how much. If you're measuring by some technique and you come up with the bore as mow being smaller than it started out life, by ANY amount, then the measurement is wrong; unreliable and meaningless. Throw it out, ignore it, and move on.

Lay your thinnest feeler gauge on a flat surface, and feel how it feels when you catch your fingernail on the edge of it. That's usually .0015" (one and a half thousandths) in most gauge sets. Compare what you feel in your housing, to that.

Personally what I see in those pics just doesn't look all that bad. I'd clean up the bore with some sandpaper, sand or file (making sure to get it STRAIGHT AND FLAT) a couple of .001"s off the mating surfaces of the cap, and put it back together. One of 2 things will happen: either it will work, in which case, .... it works; or it won't, in which case you won't have lost anything and instead maybe gained some time to be looking for anohter housing while your car is at least driving even if not perfect.

SLEEPER 86

I noticed what could be knurling marks on either side of the ds cap, does anyone recall seeing anything like that on 9bolt caps before? Looks like 2 rows of 4 or 5 dots parallel to the flat I ground for the T/A cover.
Could that be a repair attempt?
I'm still going to find someone with better measuring equipment than I have. But will probably end up taking SOFA's advise. I'd just like to avoid any problems if something isn't right.