Thanks to the many posts on differential fluid changes, I managed to change the differential fluid on my 98 E320.

I first remove the fill plug, then the drain plug (located on opposite sides). While the old fluid was draining, I remove the vent tube with my 17mm open end wrench. I removed the top cap of the vent tube and cleaned the felt filter and drain tube. After replacing the vent tube I put the drain plug back on and put in fresh differential fluid.

I noticed that the old differential fluid was dark brown in color (similar to pancake syrup) and only drained out 1.1 qts. The refill took 1.4 qts. which correlates to the manual.

Some helpful hints I used were to raise the car up on all four wheels and remove the driver side rear wheel. Place a 18" clear hose on the quart of differential fluid and position the quart jug up in the wheel wheel (this allows easier filling since the quart jug is at a higher elevation than the fill opening). Place the other end of the hose in the fill opening and commence filling until the fluid runs out of the fill opening (keep the drain pan in place to allow fluid to spill into the drain pan). Use anti-sieze compond on the threads of the fill and drain plugs to allow easier removing in the future. Wipe the differential housing with rags, this will alert you if there are any leaks.

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Ray
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles

Rjnonnie.

Would you please tell me the location of fill plug. I try to look it. Could not find. I know the drain plug it on the left side of rear axle. But I could not find the drain plug. I know it in cover of the differential. But could not see it. Would please tell me how it and what allen size to use with the fill plug.

Thanks

Drain plug is on the right side of diff at bottom. Fill plug is on left side in middle.
Both are 14mm allen.

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Mercedes Benz Master Tech - Retired

I have a W210 E420 with ASR.
It appears that the plugs are 13mm Allen and NOT 14 mm - go figure!

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2008 S550
2010 GLK350
1997 E420 (retired)
2005 CLK500 (retired)

Ray:

Good job - ya got it done.

Allow me to suggest something that might save you some time next gear oil change. I've used the following approach for 30 something years on domestic, asian, euro cars, SUVs, pick-ups, etc. It applies to rear wheel drive cars, but might also work on front-wheel.

Drain as you did, always removing the fill plug first. When it's time to refill, take a long(6-10 fts) stretch of large black rubber heater hose and insert the 2-3 in. plastic tip from a cheap funnel/hose setup that you can get at Wal-Mart, etc. Put a hose clamp around the end of the rubber hose where you insert the plastic tip and tighten it down good enough to keep it from falling off. You don't want this falling into your differential.

Now fish the hose over the top of a rear tire and downwards and towards the fill hole. Insert the plastic tip into the fill hole. Insert a funnel into the other end of the hose and start pouring in your gear oil. It's best to use a funnel with not too big an end so as to not seal up the end of the hose you're pouring into, otherwise, it can take awhile for the gear oil to drain through the hose and into the differential fill hole.

Hoses and other implements to court gravity certainly work, but can be messy, and are not always needed.

In most cases, the plastic bottles gear oil comes in can be squeezed to expel a good 2/3 (or more) of the oil at an upward angle without the benefit of gravity. Bottle can then be refilled, and another 2/3 of a quart can be 'injected' in. If the bottle has a nice pointy spout, this usually works with little or no mess, and it is easy to cuttoff the supply right at the point of overflow.

Anyways, most diffs have plenty of clearance for this simple method. Many manual trannies do not...

Best of luck.

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1986 300E 5-Speed 240k mi.

[QUOTE]Originally posted by csnow
[B]Hoses and other implements to court gravity certainly work, but can be messy, and are not always needed.

Go back and read the original post. He removed drivers side wheel to facilitate access + elevated car.

A suitable length of hose eliminates the need to do this.

Would the procedure be the same for a 300E 4matic?

What brand of fluid should i use?

Thanks very much for your reply.

Good point but the main reason to elevate the car and remove the drivers side wheel was to get underneath the car to remove the drain plugs. Since I do not have a car lift, I rely on jack stands which are capable of elevating the car about 8" off the floor.

I also screwed an adaptor device on the quart of diff fluid. The adaptor has a quarter turn shut-off with a 1/2" round opening on the end to slip a hose over. They are available at most auto parts stores.

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Ray
1998 Mercedes E320, 200K Miles
2001 Acura 3.2TL, 178K Miles
1992 Chevy Astro, 205K Miles

On a W210 E300DT they are definitely not 13mm. I would guess 14mm or larger.

Anyone know for sure?

Thanks!

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2005 Pathfinder LE
2001 E55
1998 M3
1982 320i

Did mine a couple of months ago - 14mm. Rear needs to be on level "ground" to get the level right I believe. If the wheels are hanging, then the level will be off. I just leave mine on the ground to drain and fill. It's a little tight but not too bad. Fluid really comes out fast when it's hot too. I've also got a pump unit that attaches to the oil bottle that allows you pump the fluid uphill - very slick and easy. Cost under five bucks.

Len
'99 E3000TD 89,000 miles

I like the small squeeze bottles myself.

mercedes has a special tool with 13mm oil plug lug on one side and the 14mm allen on the other for doing differential drains.

The tool is made by Hazet and part # is 117-589-02-07-00.

It fits most mercedes diff drain plugs and oil plugs and is a must for every tech at the dealerships.