What type of oil do I buy to change my ZL1's differential fluid?

[alex3d]

Does anybody have any experience with Castrol? i have always used becouse personal preference for motor oil. i was wondering if it says that meets the GL-5 regulation for the ZL1 why nobody talk about it?

Castrol/Syntrax Limited Slip gear oil SAE 75W-90 32 oz.

Part Number: 6674

Castrol Syntrax™ Limited Slip Gear oil is a synthetic formulation that provides maximum protection under.

• Premium full synthetic for added assurance during extended drain intervals
• Improved thermal stability and excellent shear stability for superior wear protection
• Full compatibility with all conventional and synthetic API GL-5 and MT-1 gear oils
• Exceeds the service fill requirements of conventional and limited slip differentials calling for SAE

[ZMEnow]

Originally Posted by alex3d

Does anybody have any experience with Castrol? i have always used becouse personal preference for motor oil. i was wondering if it says that meets the GL-5 regulation for the ZL1 why nobody talk about it?

Castrol/Syntrax Limited Slip gear oil SAE 75W-90 32 oz.

Part Number: 6674

Castrol Syntrax™ Limited Slip Gear oil is a synthetic formulation that provides maximum protection under.

• Premium full synthetic for added assurance during extended drain intervals
• Improved thermal stability and excellent shear stability for superior wear protection
• Full compatibility with all conventional and synthetic API GL-5 and MT-1 gear oils
• Exceeds the service fill requirements of conventional and limited slip differentials calling for SAE

This pig unit is temperamental to oil in the clutch packs so why not use what GM recommends.

[alex3d]

$30 a quarter in the stealership x 3 to fill up the 2.1 quarters = $90
+ $90/ hour servicing the car
+ gass and wear driving to the stealership
-------------------------------------------------
Total about $200

vs.

3 quarters of valvoline or castrol well selected product that meets the specs, =$40
+ installed by my self
--------------------------------------------
Total $40

$200 vs. $40 that's why

[ZMEnow]

Originally Posted by alex3d

$30 a quarter in the stealership x 3 to fill up the 2.1 quarters = $90
+ $90/ hour servicing the car
+ gass and wear driving to the stealership
-------------------------------------------------
Total about $200

vs.

3 quarters of valvoline or castrol well selected product that meets the specs, =$40
+ installed by my self
--------------------------------------------
Total $40


$200 vs. $40 that's why

I am missing something you note the cost for the dealer to install and then reference you do it yourself. If you are doing it yourself you are spending an extra $50 bucks on a 60K fun car to make the clutch packs happy.. On second thought use the Castrol..

[DrkPhx]

Originally Posted by ZMEnow

This pig unit is temperamental to oil in the clutch packs so why not use what GM recommends.

Exactly right. It works great. For the record, I also added a little extra GM limited slip additive when I changed mine. It's now quiet and no low speed groans.