# Diff fluid FM



## SWGOAT (Nov 9, 2010)

I recently changed out Diff and trans fluids with RP Syncromesh and Max Gear, trans is very smooth and quiet, big improvement, however diff still has whining sound in 4th and 5th at 2k to 4k rpm range, no chatter present and diff made same sounds with OEM gear oil. Car has 53k miles, 3k while I have owned it, past owner had all service records and car was maintained through local dealership. My question has anyone used RP product and added FM like Amsoil or Redline? Would this help or is the noise common and more gear or bearing related to drivetrain. Noise it at rear end. Whining noise is present with or without clutch engaged, some of noise is tires, any thoughts?


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## Falco21 (May 11, 2010)

I would highly advise to remove that out of there. There have been tons of owners that used RP and blew their differentials. Go with Torco Gear Oil and F Modifier and don't look back.


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## Falco21 (May 11, 2010)

Read here. Good info:

Torco RGO FTW!!!!! - LS1GTO.com Forums


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## SWGOAT (Nov 9, 2010)

Good call, just read posts, Torco 85w-140, bit confused on friction modifer, F type is listed as except GM posi limited slip and G type listed for GM posi limited slip? F or G type? I would like to try product ASAP. Thanks


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## Falco21 (May 11, 2010)

F. This was a going concern for a while, but it is F. 

That stuff is like magic. Trust me. If you have any issues still, try this out. If it persists, it could be something more, but start here. RP has had their share of problems with Gear Oil.


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## SWGOAT (Nov 9, 2010)

Ordered 2 liters Torco 85w-140 and a bottle of type F friction modifier, change fluids when I receive my order. Will note any change in performance. Thanks for the heads up.


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## Falco21 (May 11, 2010)

No problem man. Update here and let us know.


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