1990 300SE
Engine 103.981
Chassis 126.024

The fastlane website calls for 75/90W. Here is a copy/paste:

Note: 75/90W GL-5 Synthetic
Fully Synthetic Gear Oil - 1 Liter Fully synthetic multi-grade gear oil with a broad viscosity spread. Allows for easier shifting and quieter operation. Gives outstanding wear and corrosion protection. For manual transmissions, transaxles and rear axles where API GL-5 is specified. Please refer to owner manual for specific application! <-------I didn't see this part

I have put Mobile 1 synthetic 75/90W in and was reviewing the service manual AFTER I finished the job (real smart, huh?) and noticed that the service manual calls for 85/90W or 90. This differential does not have limited slip (I couldn't find the badge anywhere).

Am I OK using this 75/90W or should I drain it and use the correct weight. I can live with pouring out 8 dollars of gear oil, and next time I will read more carefully.

Michael C.

that's what is in mine.

__________________
82 300D....went to MB heaven
90 350 SDL....excercising con rods

Thanks, I thought it would be OK, but I just wanted a second opinion.

I was delighted to see that the used oil I drained out looked great (clear and light brown, and looked like about a liter or so. The reason I mention this is because the service history for this car is unknown from 1990-2004.

P.S. You guys weren't kidding about the difficulty in removing the plugs, however, I did remember to:

1. ALWAYS remove the fill plug first.
2. Allowing some PB blaster to soak in really good before I attempted to remove the fill and drain plugs.
3. Tap GENTLY on the plugs with a small ball peen hammer.

Yes, I still grunted a bit, threw out my back, pulled a few muscles, etc....
NAH, just kidding... It went smoothly thanks to the tips and tricks I found here in the forum.

Have a great day guys!