Author Topic: 12 bolt rear end...what kind of gear lube to use? :)  (Read 11832 times)

Offline GUITAR1989

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12 bolt rear end...what kind of gear lube to use? :)
« on: February 03, 2011, 11:04:14 PM »
Hey guys I need to change the fluid in my trucks rear end :) I was just wondering what kind of gear lubricant to use. The rear end is a GM 12 bolt. Thanks for your time
 Shayne

Offline SAATR

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Re: 12 bolt rear end...what kind of gear lube to use? :)
« Reply #1 on: February 03, 2011, 11:30:21 PM »
Likely a 75w90 or an 80w90.  I like Royal Purple and Valvoline Durablend, both have served me well in the past.  If you have a clutch type posi, be sure to put some limited slip additive in first to prevent it from chattering.

Offline Grim 82

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Re: 12 bolt rear end...what kind of gear lube to use? :)
« Reply #2 on: February 04, 2011, 12:04:40 AM »
+1
80w90. I've been using synthetic Valvoline on my last few trucks with good results. If you have a performance diff figure out what you have and use the oil or additive you need for that application.
Give a man a gun, and he might rob a bank. Give a man a bank, and he might rob the world.

Offline GUITAR1989

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Re: 12 bolt rear end...what kind of gear lube to use? :)
« Reply #3 on: February 04, 2011, 12:14:14 AM »
nice thanks guys. I think what my truck has is called open differential..When I have the rear jacked up I can spin a wheel and the other one doesnt move. Does that need an additive?

Offline Grim 82

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Re: 12 bolt rear end...what kind of gear lube to use? :)
« Reply #4 on: February 04, 2011, 12:56:19 AM »
You probably have a stock open diff, so you can just use a conventional oil. Pop the cover and if it has all kinds of gadgets in there take a pic and we can tell you if it's something different.
Give a man a gun, and he might rob a bank. Give a man a bank, and he might rob the world.