DIY - Differential Fluid Change - Benzworld.org

netdvn · 08-08-2006, 03:35 PM

Probably this subject was posted earlier but I can't find it. Does any one know how to change the differential fluid on E320? I want to replace the original fluid with a synthetic oil (Mobil 1 W75-90).

Thanks,
netdvn

sokoloff · 08-09-2006, 09:45 AM

Very easy - do it hot. Remove the fill plug. Remove the drain plug. Drain the old fluid. Replace the drain plug. Fill it with new fluid. Replace the fill plug. Be on your merry way. Plugs are 14mm. You need something to pump the fluid "uphill" to refill. I have pump that screws right onto the bottles.

Len

omeyhomey · 08-09-2006, 11:53 AM

Use Royal Purple max gear or Lucas oil performance diff oil w/ some lucas oil oil stabilizer. either will give you maximum performance.

netdvn · 08-09-2006, 03:05 PM

Thanks Len and Omeyhomey, I just got an allen wrench set (including 14mm) on Ebay from Brand On Sale for $9.99 w/ $8.99 S&H. I'm going to work on my both vehicles this weekend.

Lucas or Mobil 1, which one is better?

netdvn · 08-14-2006, 05:30 PM

Quote:

Originally Posted by omeyhomey

Use Royal Purple max gear or Lucas oil performance diff oil w/ some lucas oil oil stabilizer. either will give you maximum performance.

Update!!! I changed the oil on my E320 (83K) last weekend, using Lucas W80/90 (without mixing the Lucas Oil Stabilizer). I made two 25-mile trips today and the mileage reduces from 29 to 26 miles per gallon. Do you have any idea? If oil stabilizer is needed, what's the ratio? My SLK is about 43K and I'm going to replace its diff. fluid soon too.

Thanks,
netdvn

sokoloff · 08-15-2006, 01:52 PM

I don't think two 25 mile trips will tel you anything. Try a couple of tankfuls and see.

Len

netdvn · 08-15-2006, 04:25 PM

Quote:

Originally Posted by sokoloff

I don't think two 25 mile trips will tel you anything. Try a couple of tankfuls and see.

Len

Thanks Len, Lucas is a good stuff and even better than Mobil 1 (according to the labes on the the bottles). I will make a 3-hr trip trip to Northern Virginia this weekend.
Does oil stabilizer make the oil thicker?

If that is the case, I don't need need to mix it because what I got is thick enough for my Benzs.

cerritos · 09-15-2006, 08:03 PM

FSS does not mention anything about differential fluid change. Does this mean it's also one of those MB's life time fluid as the transmission?

When should the differential fluid be changed? 30K miles? 45K miles? 60K miles?

There are three different MB part numbers for differential fluid:

1. MB 000 989 28 03 (for rear axle differential and for refilling 4Matic front differential)

2. MB 001 989 17 03 (for LSD and rear axle with ASD, 4matic)

3. MB 001 989 05 03 (for initial fill of 4matic fron differential Life-Long hypoid gear oil)

Which one is for 2001 E320? I guess it should be #2. ?? #1 and #3 seem to be for front differentials.

Please provide input. Thanks.

inssane3gt · 10-20-2006, 04:07 PM

I just finished changing my diff oil on my 00 E320. I used Mobil 1 75w-90, the dealer didn't stock the part numbers mentioned above. You could order them but they're outrageously expensive. The Mobil synthetic is $10 a quart.

I had some trouble finding a 14mm allen wrench, I found a set a Harbor Freight. I got the extra long set. Use a 14mm allen wrench and a 14mm wrench to get the plugs off.

I used my Mityvac hand pump (Sears, $15) to get the new fluid in the diff.

ooifa · 10-22-2006, 10:47 PM

May I know how many quarts is needed for the oil change? Btw I am driving a 94 W124 E280 4 speed auto .I guess should be about the same.