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Old 09-22-2006, 08:52 AM   #1
Luvlegs
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Are these normal machining marks?????

Popped open the diff last night - lo and behold - the gears are NOT what the axle codes indicated (3.73)....
the ring reads "3817778 11:4 GM 10-71 2" ....

Are the marks that look like teeth groves (to the right of the ring gear) normal? I wonder if it was prior damage that lead to the gears being changed....?? It's all nice and clean in there, no shavings, no rubbing, no binding, was very quiet when driven, no vibrations or anything noticable.

Also, compared to what I thought were 3.73s - what's this going to do to my mileage, take off, top end, etc.... I am working on a 454 right now to put in.... eventually, go to posi when I locate one.

Thanks for any input.
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Old 09-22-2006, 08:57 AM   #2
Jim_PA
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Re: Are these normal machining marks?????

That's far from normal. My guess is that the Pinion gear made those marks some time ago.
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Old 09-22-2006, 09:04 AM   #3
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Re: Are these normal machining marks?????

Also, confirm all those numbers, I don't see anything that looks like a ring and pinion count number.

43:14 = 3.08
41:11 = 3.73 (and it looks like that's what you have, but hard to tell from the numbers I see in the pictures.)...
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Old 09-22-2006, 10:49 AM   #4
Green Machine
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Re: Are these normal machining marks?????

I agree, pinion got loose or pinion bearings went out at some point and chewed the carrier, shouldn't hurt anything, but the carrier may be weaker now because of metal loss. Should be ok until you get your posi. If you can't read the tooth count on the ring gear you can manually count them to get the ratio, I'm betting it is a 3.73 - 11 and 41.
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Old 09-22-2006, 11:48 AM   #5
Luvlegs
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Re: Are these normal machining marks?????

I went back and looked - also did a little photo zooming - it appears that the numbers are actually "11 : 41" - the last "1" is very faint and only the top of it is stamped very deep - I have learned again - so it IS 3.73... THANKS A TON guys!
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(you don't always have to state the obvious)

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1972 C10 L6 3OTT
2005 F350 - Built - whew!
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