MB Spec 235.7 gear oil

[Egg_Head]

Helping my neighbor this weekend with his 2006 C350. One thing on the list is rear diff gear oil change. Will the world stop spinning and the rear end drop out if we use Castrol Syntrax LS 75W-90 which he has in his stash or do we need to get a spec'd 235.7 oil which would mean from the dealership today? I see the 235.7 is 75W-85, is this for better fuel economy?

 

[Audios]

Get the right stuff, only thing my parts program is approving is Redline 75/85 GL-5 or OEM fluid at 38$ each. It only takes one liter so best to play it safe and just get the right stuff in there.

 

[zeng]

Originally Posted By: Egg_Head
Helping my neighbor this weekend with his 2006 C350. One thing on the list is rear diff gear oil change. Will the world stop spinning and the rear end drop out if we use Castrol Syntrax LS 75W-90 which he has in his stash or do we need to get a spec'd 235.7 oil which would mean from the dealership today? I see the 235.7 is 75W-85, is this for better fuel economy?

The 75W90 in the stash is good to go.

 

[Pelican]

Originally Posted By: Egg_Head
Helping my neighbor this weekend with his 2006 C350. One thing on the list is rear diff gear oil change. Will the world stop spinning and the rear end drop out if we use Castrol Syntrax LS 75W-90 which he has in his stash or do we need to get a spec'd 235.7 oil which would mean from the dealership today? I see the 235.7 is 75W-85, is this for better fuel economy?


Compare the cost of the lubricant vs the cost of a rear end, then you can decide whether to gamble.

 

[Dino01]

Use the approved stuff from the BEVO site, there are plenty of places to get the OE-approved stuff. There have been reports on the various forums over the years, sporadically, of people developing gear whines when not using the approved stuff. You may be fine, but I'd rather not test it.

In the CLK I only use 235.0 85w90 gear oil, every 50k so it's a minimal expense.

https://bevo.mercedes-benz.com/bevolisten/235.7_en.html