Author Topic: Where can I find my rear end gear ratio?  (Read 69502 times)

Offline autorepr

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Re: Where can I find my rear end gear ratio?
« Reply #30 on: June 15, 2011, 06:34:14 AM »
If you jack it up and try to turn the wheels on an open diff. you end up spinning the spider gears in the differental and it does not give you usable info. Whichever wheel you spin the other turns the other direction and the driveshaft does not turn. It would work on a posi or locked locker.

As far as which is easiest I guess it's just a matter of preference. Pulling the cover would be 100% accurate. Doing it this way just saves jacking it up, the mess, the time to clean gasket surfaces and resealing and refilling.
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Offline ehjorten

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Re: Where can I find my rear end gear ratio?
« Reply #31 on: June 15, 2011, 02:07:30 PM »
When was the last time the gear oil was changed in the diff?  Pull the cover, inspect the oil for metal shavings, count the teeth or read the stamped ratio, new gasket and install cover, fill and now you know! :D
-Erik-
1991 V3500 - Gen V TBI 454, 4L80E, NP205, 14 bolt FF, D60, 8" Lift on 35s
1977 K20 Silverado - 350, THM350, NP203, 14 bolt FF, D44, Stock Lift on 31s
1969 Chevelle Malibu Sport Coupe - EFI350, THM350
1968 Chevrolet Step-side Pickup - 300HP L6

Offline jbell1

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Re: Where can I find my rear end gear ratio?
« Reply #32 on: June 16, 2011, 04:20:18 PM »
Sorry I haven't been on in a few days but i'm currently taking finals for school i restart work on the truck monday, thats the first on my list and pretty sure the oil was never changed.
1985 Chevy C20 (my baby)

Offline Blazin

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Re: Where can I find my rear end gear ratio?
« Reply #33 on: June 17, 2011, 06:18:40 PM »
If you jack it up you only jack one wheel. Think thats why he wrote " jack the wheel " singular.
Best way is to pull the cover. Buy a few quarts of 80 / 90 gear oil, several cans of brake clean, a high quality silicone to make the new gasket. and spend 30 minutes under there. 
Some people are like Slinkies. Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs