jpz28

I'm wanting t do a gear oil change on my rear but want to know what kind of gear oil to use??....It came with Redline synthetic according to the seller from whom I got it from and it held up real good...I just don't know what weight....?? The following is my rearend:
stock 10 bolt w/ eaton posi unit & 3.73's ....it also has a TA cover on it...

I want to use the same Redline oil but need to know what weight and how many bottles to buy??....Do I need any Limited slip additive??...Thanx...

Also just for the record how often should it be changed????

Deeavi

iTrader: (16)

I use the Mobil 1 gear oil plus a limited slip additive.

Depends on how you drive as to when to change it, but normally you can go a while before changing gear oil, 30,000 miles under normal conditions!

ElecTA

i thought with the eaton posi you are not supposed to use synthetic, just 80 90 and 4 ounces of limited slip. please correct me if im wrong.

Deeavi

iTrader: (16)

I don't know where you heard that! I have been using it for years.

The weight is 75w-90 and it is always better to use a synthetic if you can

Read this:


"Mobil 1 Synthetic Gear Lubricant LS 75W-90


Product Description Features & Benefits Applications Specifications & Approvals Typical Properties Health & Safety

Product Description
Mobil 1 Synthetic Gear Lubricant LS is a supreme performance, synthetic, multi-purpose, SAE 75W-90 automotive gear lubricant designed to meet the highest level performance requirements of modern passenger vehicles in all types of operating conditions including limited slip applications, as well as, deliver outstanding power transfer performance. Compared to conventional hypoid gear lubricants, Mobil 1 Synthetic Gear Lubricants LS 75W-90 performs exceptionally over a wide range of temperatures. Mobil 1 Synthetic Gear Lubricant LS 75W-90 achieves this through a unique proprietary formulation, that deliver optimized viscosity-temperature properties together with the highest level of inherent formulation stability and protects against thermal and oxidative degradation, wear and corrosion, viscosity loss associated with premature shearing. It also can be used in extended service and for aiding in fuel economy performance.

Mobil 1 Synthetic Gear Lubricant LS 75W-90 meets the most severe API Service MT-1 and GL-5 EP gear oil service classification.

Features & Benefits
Mobil 1 Synthetic Gear Lubricant LS 75W-90 combines wax-free synthesized hydrocarbon base oils and a specially designed extreme-pressure, limited-slip, sulfur-phosphorous additive system to provide a significantly higher level of performance in rear axles and differentials versus conventional fluids. Greater film strength at higher operating temperatures, reduced fluid friction and low-temperature application down to -50ēC provides significant advantages versus conventional mineral oil formulations. It reduces wear and spalling under the high speed, high torque and high horsepower conditions in competitive racing and high performance automobiles. This unique, high technology final drive gear lubricant has demonstrated outstanding performance including; fuel economy, extended drain, long-term friction retention, low-temperature capability and improved differential/axle durability and cleanliness. Key features and benefits include:


Features
Advantages and Potential Benefits
Exceptional thermal stability and resistance to high temperature oxidation Extended gear and bearing life due to minimal deposits
Longer seal life
Potential extended oil drain/service intervals
Outstanding protection against low speed/high torque wear and against high speed scoring Capability to handle the severest driving conditions while delivering smooth efficient and reliable performance
Exceptional shear stability Retains viscosity and film strength under severe operating conditions to prevent wear
Excellent rust, staining and corrosion protection of copper and its alloys Reduced wear
Longer component life
Enhanced frictional properties Improved fuel economy and reduced operating costs
Outstanding low temperature fluidity versus mineral oils Reduced wear at start up and ease of start up even in arctic conditions
Good resistance to foaming Maintains film strength for reliable lubrication
Compatible with typical automotive seals and gaskets Minimum leakage and reduced contamination
Excellent limited-slip performance Reduced chatter and improved traction

Applications

Mobil 1 Synthetic Gear Lubricant LS 75W-90 is recommended for use in modern high performance automobiles like SUV's, Vans and Light duty trucks requiring API GL-5 & MT-1 level performance
Mobil 1 Synthetic gear Lubricant LS 75W-90 is intended for initial fill, topping-off or refilling differentials, final drives, transfer cases and other gear applications where lubricants meeting API Service GL-5 and multi-purpose or mild EP gear lubricants are recommended
Mobil 1 Synthetic Gear Lubricant LS 75W-90 can also be used in rear axles where API Service GL-4 lubricant is recommended
Not recommended for automatic, manual or semiautomatic transmissions for which engine oil or automatic transmission fluids are recommended
Where extended service intervals and warranties are require


Specifications & Approvals

Mobil 1 Synthetic Gear Lubricant LS meets or exceeds the following industry specifications:
75W-90
API Gl-5/MT-1 X


Typical Properties

Mobil 1 Synthetic Gear Lubricant LS

SAE Grade 75W-90
Viscosity, ASTM D 445
cSt @ 40ēC 106
cst @ 100ēC 15.2
Viscosity Index, ASTM D 2270 150
Pour Point, ēC, ASTM D 97 -46
Flash Point, ēC, ASTM D 92 175
Density@15C kg/l, ASTM D 4052 0.859




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Health & Safety
Based on available information, this product is not expected to produce adverse effects on health when used for the intended application and the recommendations provided in the Material Safety Data Sheet (MSDS) are followed. MSDS's are available upon request through your sales contract office, or via the Internet. This product should not be used for purposes other than its intended use. If disposing of used product, take care to protect the environment.

The Mobil logotype, the Pegasus design, Mobil 1 Gear Lubricant are trademarks of Exxon Mobil Corporation, or one of its subsidiaries."

03-2004

ElecTA

i had a problem with my eaton posi and this is the response i got from someone at eaton.

The Eaton Posi(TM) differential is the finest differential available on
the market and should provide you with years of worry free use. Chatter
(noise) is rarely an issue with the Eaton Posi(TM) differential.

Be sure it is installed correctly.
Use GL-5 mineral based lube. No synthetics as they tend to cause noise.
Be certain to use 4 oz of LSD additive.
Change the lube after the first 500 miles driven and replace with
mineral based lube and 4 oz of LSD additive. If you have done that and
you still have some noise, you can add 4 oz more of the additive.

If these tips do not work, contact me. But I think they should correct
the problem.

Regards,

Jeff Phillips
Eaton Automotive

Deeavi

iTrader: (16)

Personally I have been working on cars for along time and as far as the rear end it is not going to make that much difference. I choose to use synthetics, because I have used them extensively and they work better than mineral based oils. I have also done allot of research, but you have to do what you believe is right! I know this! The so-called experts aren't always right!?!

You asked, and I told you what I do, but it is your car so you have to make that decision.