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Author Topic: I'm new to 3/4 ton axles  (Read 3209 times)

Offline bfofish

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I'm new to 3/4 ton axles
« on: November 11, 2007, 11:26:35 pm »
I recently picked up a 89 Blazer with 3/4 ton axles on it,and now it is tome to go through them.Problem is I know very little about them,I will be tearing into them on Thursday.I need to know what weight of lube to put back in,and is it the same for front and rear?The local part stores can't give me a straight answer because I can't tell them what year the axles are.I have no clue what year they are from neither did the p.o.
I think the rear is a 14 bolt ff and I can see the front is a 10 bolt.Here are a couple of pics. Let me know if I am wrong about what I have,like I said I know very little about 3/4 ton stuff.     Any help is appreciated
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Offline VileZambonie

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Re: I'm new to 3/4 ton axles
« Reply #1 on: November 12, 2007, 04:45:43 am »
80w90 is fine. If it is limited slip you will need the additive.
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Offline 78ScottsdaleK20

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Re: I'm new to 3/4 ton axles
« Reply #2 on: November 17, 2007, 10:15:05 am »
Check for id marks on the axles. You can find them around the diff cover, on the axle housing (tube). Your best guess is with most 3/4 ton trucks and blazers, are Dana 44 up front and GM corporate 14 bolt in the rear. Then have to find out what size your ring gear, 9 1/2 or 10 1/2. Only way to tell is open her up.
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Offline Fordeatinz71

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Re: I'm new to 3/4 ton axles
« Reply #3 on: November 17, 2007, 05:00:39 pm »
yep, 80w90 works fine for all the 10 and 14-bolt axles...as mentioned, if you rip off the rear cover and see a limited slip then just throw in some limited slip additive.  must not be a competent parts store...all 10-bolt and 14-bolts called for 80w90 gear oil as far as i knew...in ALL years
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Offline 1976Scottsdale

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Re: I'm new to 3/4 ton axles
« Reply #4 on: November 17, 2007, 11:33:13 pm »
Your rear has a 10.5" ring gear in it.  The front is 8.5".  You will not need any additive in the front diff, maybe in the back one though.
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