Buy Now, Pay Later with Affirm
On orders over $200
100% Money Back on Select Parts
Red Line 75W90 Gear Oil 1QT ( Part Number:RDL 57904)

Red Line 75W90 Gear Oil 1QT - Universal

MODEL # RDL 57904
Manufacturer Part # 57904


In stock! Ships same day
Free shipping on all orders over $200.00!


Red Line's Gear Lubricants are designed to provide the highest degree of protection and greatest efficiency for your drive train. Red Line provides a complete line of drive train lubricants which are optimized for differential, transmission, or transaxle use over a wide range of temperatures. Proper selection depends upon the manufacturers' requirements and whether the application is for passenger automotive, commercial, or racing use. Red Line Gear Oils contain polyol ester base stocks to provide excellent lubrication even under extreme conditions of high-loading and high- temperatures--their natural lubricity provide excellent slipperiness which reduces the sliding friction in hypoid gears to reduce wear and temperatures. The synthetic base stocks have a natural multi-grade property, so large amounts of unstable thickeners are not required to manufacture their gear oils, which means that Red Line Gear Oils will provide a stable viscosity for even extended periods of use. Red Line also manufactures gear oils which can be used in limited-slip differentials without the use of additional friction modifiers.

The Red Line 70W90 is the most popular gear oil, this is the preferred product in nearly all car and light truck differentials, both conventional and limited-slip. 75W90 is preferred for most racing applications. It contains friction modifier which is recommended for limited-slip units. 75W90 Gear Oil can be used in many transmissions and transaxles; however, other Red Line lubricants have better frictional properties for rapid synchronization. Exceeds API GL-5.

This oil is recommended for Subaru differentials.
| | | | |


Brand: Red Line
Class: GL5
Friction Modifier: Yes
Type: Synthetic
Volume: 1 qt
Color: Yellow

Mfgr. Warranty: No Warranty
Condition: New Product
Return Policy:

RallySport Guarantee - 30 Days

Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.



This product has no user uploaded media. You can upload your photo or video of your install by posting a review. Reviews:

Works good in 2002 wrx
Saltdscott56541 3 years ago
This fluid works great in my 2002 wrx. Don't listen to the people reviewing this who put this i there sti rear dif. The STI has clutches that Wes doesn't so the STI requires a different type of fluid

Works great !
Fidrat 4 years ago
In my 03 WRX rear diff, I use Redline 75W90 at the recommended interval in my owners manual.The bad reviews come from Sti owners. NOT THE SAME DIFF!! , The WRX uses a viscous LSD where the STi uses a mechanical unit. I have 54,000mi on this oil in my rear diff and I haven't given it a second thought.
Verified Purchase

no good
mkivjacob 6 years ago
i got the same metal grinding sound in my 06 sti i am going to change it to motul and hope the same doesnt come from it!
Verified Purchase

Not too sure.
faraco3 7 years ago
I recently changed the fluid in the rear differential on my 2006 sti from the OEM fluid to this Redline 75w90 fluid. Initially there seemed to be no difference, but after 4 or 5 days I began to hear a metal on metal sound coming from the rear differential. After 7 days I couldn't stand the sound any longer, so I replaced the fluid with OEM fluid from the dealership. I don't know if the fluid hurt my LSD, but just to be safe I will keep the fluid OEM.

  • Q: red line 75w90 gear oil  Guillermo 2 months ago


    hi I have a 2014 Subaru sti hatchack I was wondering what this rear diff oil would it be okay to use?

    • A: This will be a great oil to use for your rear diff fluid.

      Jared A. 1 month ago
  • Q: Flywheel change   jdsmith123125605 5 years ago


    I'm changing my flywheel in my 06 wrx and putting in an ACT streetlight flywheel what's the best gear oil to go with

    • A: For the transmission Redline states to use the 75W90-NS gear oil

      Kirill C. 5 years ago
  • Q: is it ok for my diff  wrxridehawaii 7 years ago


    Hi is this gear oil going to be ok in my Diff(04wrx)? or am i going to have problems like the guy with the 06 sti and his diff?

    • A: yeah this should work great, the WRX uses a viscous LSD where the STi uses a mechanical unit. While I have never seen any problems in an STi differential, I have used this personally in several of my WRX rear diffs and I love it. Thanks. :)

      Rick C. 7 years ago
Universal Product
This item is non application specific.
Please verify compatibility before purchase. May require some modification for proper installation.