genius

how do you check the differantial fluid?
what color is it?
If it is low, where to add it?

pcy

Typical differential has a drain plug (to remove the fluid) and a fill plug (to fill the new fluid). After removing the old fluid via drain plug and putting back the drain plug, you'd pour the new fluid via fill hole until the fluid starts coming out. The fill hole is at the max level of the diff fluid. So, you won't be able to over-fill of you try to.

Please note that some differentials (like the front diff on my front '07 C280 4Matic) have just one plug - for removing the fluid and adding new fluid.

genius

thanks for the info and appreciate it.

but is there a dip somewhere to check the amount?
also what color is the fluid and what kind do you use?

Glyn M Ruck

https://mbworld.org/forums/c-class-w...fill-plug.html

30 is level plug


Axle fluids should meet Benz approval 235.7 Part number A001 989 33 03 10 or approval spec 235.9 - Available at your Benz dealer.

Glyn M Ruck

Here's the tranfer case - more complicated. Diffs are dead easy

I hope you are a genius

You have some work to do.

lkfoster

I had planned to change my rear diff oil with Mobil 1 Synthetic Gear Lubricant LS 75W-90, but now you've got me wondering if it's the right oil. The Mobil page doesn't say anything about 235.7. Will this thinner oil be OK? I live where summer temps get up to the mid-40s C.

Glyn M Ruck

The 235.8 spec is for 75W-90 so that's correct viscosity. I thought the Mobil was approved - will take a look & report back

Please note I meant 235.8 above & not 235.9

pcy

I thought that MB recommends 85W-90 diff fluid...

Glyn M Ruck

Steadily changed over time to one size fits all for all temperature conditions & as high VI synthetics have become available. i.e. behaves like a 75W when cold & like a 90 when hot.

Synthetics thin out less with increased temperatures over normal petroleum fluids.

contact148

you might not be able to find any mb spec fluid I was unable to get any in canada (had to import a case from usa) way to much $$$ to do that

so I used valvoline same as the 2 local dealer use here.....

97W202

how often should this fluid be changed?? thanks!

Glyn M Ruck

Every 75 to a 100,000 miles is a good call.

OneOfaKindTrini

You guys should look into AMSOIL for your diff.

Glyn M Ruck

AMSOIL does not hold a Benz approval as of today's listing.