Bevel box fluid, what is it?

[scrllock]

I'm trying to figure out what exactly the OE Mk7 fluid is. Part is G 052 145 S2. I assume any API GL-5 75w90 gear oil would work, but if you google the part number, you get results matching Castrol Syntrax Long life, Fuchs Sintopoid, Motul Gear 300 (two GL-5 oils and a dual-rated GL-4/GL-5).

The odd thing is if you look up a Mk7 R on various manufacture's sites, you get some different results. Motul recommends Gear 300 LS (limited slip additive), Liquimoly suggests MTF 75w90 (GL-4), Redline recommends MT-90 75w90 (GL-4) and AMSOil, their Severe Gear 75w-90 (GL-5). The same fluid is in the rear differential, which definitely isn't a limited slip stock.



I think I've also seen folks like @tigeo run LM GL4+ or Redline 75w90NS, but neither of those are approved or recommended. Anyone know if GL-4 or GL-5 is preferred, and whether you'd want limited slip additive in a bevel box?

 

[tigeo]

I'm trying to figure out what exactly the OE Mk7 fluid is. Part is G 052 145 S2. I assume any API GL-5 75w90 gear oil would work, but if you google the part number, you get results matching Castrol Syntrax Long life, Fuchs Sintopoid, Motul Gear 300 (two GL-5 oils and a dual-rated GL-4/GL-5).

The odd thing is if you look up a Mk7 R on various manufacture's sites, you get some different results. Motul recommends Gear 300 LS (limited slip additive), Liquimoly suggests MTF 75w90 (GL-4), Redline recommends MT-90 75w90 (GL-4) and AMSOil, their Severe Gear 75w-90 (GL-5). The same fluid is in the rear differential, which definitely isn't a limited slip stock.



I think I've also seen folks like @tigeo run LM GL4+ or Redline 75w90NS, but neither of those are approved or recommended. Anyone know if GL-4 or GL-5 is preferred, and whether you'd want limited slip additive in a bevel box?

I ran Redline MT90 based on the Redline site in both bevel and r. diff. It's GL-4.

 

[scrllock]

I ran Redline MT90 based on the Redline site in both bevel and r. diff. It's GL-4.

I'm still planning on running Motul Gear 300 in both since Wavetrac suggests it in the diff. Haven't seen anything conclusive on anyone preferring one thing or another in the bevel box besides the Motul stuff.

 

[tigeo]

Interesting that LM now has a GL4 fluid and it's what's recommended for the bevel and r. diff so no longer the 4+ like they used to recommend. KY undeterstanding is the the GL5 isn't good for the manual transmissions due to being "too slick" and causing issues with the syndrome. GL5 seems to be it for the diffs but then you get the LM and RL recommended GL4. WTF?

 

[MeltedSolid]

I'm just using the OEM stuff because it's not that expensive and I know it's intended for it.