2000 Mile Rear Diff Service?
10-31-2018, 01:08 PM
#26
For the DIYers....
Part #001-990-23-17 is the screw plugs and need 2 ($22.00 ea)
Part #001-989-52-03-10 Diff Oil, need about 1.5 quarts (Castrol Syntrax Limited Slip 75W-140)
New fill and drain plugs were recommended as they are snugger fit when threading on then the old ones coming off -
$90.00 in parts, 30 minutes of super easy labor - beats paying my dealership the $400.00 they quoted me.
Part #001-990-23-17 is the screw plugs and need 2 ($22.00 ea)
Part #001-989-52-03-10 Diff Oil, need about 1.5 quarts (Castrol Syntrax Limited Slip 75W-140)
New fill and drain plugs were recommended as they are snugger fit when threading on then the old ones coming off -
$90.00 in parts, 30 minutes of super easy labor - beats paying my dealership the $400.00 they quoted me.
The following 2 users liked this post by obsidianamg:
gOt BoOsT (10-31-2018),
hyperion667 (10-31-2018)
10-31-2018, 03:27 PM
#27
Senior Member
For the DIYers....
Part #001-990-23-17 is the screw plugs and need 2 ($22.00 ea)
Part #001-989-52-03-10 Diff Oil, need about 1.5 quarts (Castrol Syntrax Limited Slip 75W-140)
New fill and drain plugs were recommended as they are snugger fit when threading on then the old ones coming off -
$90.00 in parts, 30 minutes of super easy labor - beats paying my dealership the $400.00 they quoted me.
Part #001-990-23-17 is the screw plugs and need 2 ($22.00 ea)
Part #001-989-52-03-10 Diff Oil, need about 1.5 quarts (Castrol Syntrax Limited Slip 75W-140)
New fill and drain plugs were recommended as they are snugger fit when threading on then the old ones coming off -
$90.00 in parts, 30 minutes of super easy labor - beats paying my dealership the $400.00 they quoted me.
10-31-2018, 11:13 PM
#28
Ok
Do it before 2000 miles regardless of what anyone tells you.
Here's why.
Real diff. gear whine (noise at 40-50 mph) has been a constant problem for many, many years. They try to eliminate it anyway they can (composite drive shafts, dampers in the drive shaft, dampers in the rear coupler, etc...)
So, at the factory your rear diff. comes with some special fluid additive. It is oil plus ....... Salesman will tell you it's in there to allow break in of clutches. Not so.
It's there to allow brand new gears to mesh with less wear, BUT you can't use that fluid for long.
So, change it at 2K with their factory recommended oil. I think it is Castrol 75w140 with limited slip diff. additive.
I did it in mine, but I opted to get it from the MB Dealer parts dept. (with a price mark up, of course), as a precaution.
Just do it.
It's easy and cheap. After that, you should be good to go for another 20-30k miles.
Do it before 2000 miles regardless of what anyone tells you.
Here's why.
Real diff. gear whine (noise at 40-50 mph) has been a constant problem for many, many years. They try to eliminate it anyway they can (composite drive shafts, dampers in the drive shaft, dampers in the rear coupler, etc...)
So, at the factory your rear diff. comes with some special fluid additive. It is oil plus ....... Salesman will tell you it's in there to allow break in of clutches. Not so.
It's there to allow brand new gears to mesh with less wear, BUT you can't use that fluid for long.
So, change it at 2K with their factory recommended oil. I think it is Castrol 75w140 with limited slip diff. additive.
I did it in mine, but I opted to get it from the MB Dealer parts dept. (with a price mark up, of course), as a precaution.
Just do it.
It's easy and cheap. After that, you should be good to go for another 20-30k miles.
Last edited by ahesq; 10-31-2018 at 11:17 PM.
11-02-2018, 05:15 PM
#29
Member
$161.42 (inc. CostCo 15% discount) at MB of Ontario Calif.
I tried to use Rusnak in Arcadia (Calif., US) once in 2012 when I worked in nearby Pasadena and they were a pack of rude clowns so I went to Ray's MBZ (highly recommended for non-dealer essential items).
I tried to use Rusnak in Arcadia (Calif., US) once in 2012 when I worked in nearby Pasadena and they were a pack of rude clowns so I went to Ray's MBZ (highly recommended for non-dealer essential items).
The following users liked this post:
obsidianamg (11-02-2018)
11-02-2018, 05:59 PM
#30
Thanks for the heads up... Just put Ray's MBZ in my contacts, I will give them a try on next Non-Warranty/Dealer issue....
What a shame about Rusnak... Such a nice dealership but bad vibes from the service dept.
What a shame about Rusnak... Such a nice dealership but bad vibes from the service dept.
12-15-2018, 05:51 PM
#31
Senior Member
So I finally got around to changing the rear diff fluid for the second (or first) time myself after buying the car. I used the part number listed above for the rear diff fluid which come in .5L bottles from any local dealer or online. You will need 3 bottles, but you won’t use the 3rd one entirely. Before anyone says the car has to be perfectly level, it doesn’t. It is completely fine to have a slight over fill using this method.
1. Jack the car from the driver rear as little as you need to get under and access the diff so the drain plug on the passenger side is at the lowest point. Put a jack stand under the car and get to work.
2. Use a 19mm socket and 1/2” ratchet or impact gun with extensions to remove the fill plug on the driver side and then remove the drain plug on the lower passenger side of the diff. Mine were tight af as it looked like mb used thread locker of some sort. Let fluid drain into an appropriate container.
3. Clean both fill and drain plugs with a rag then wipe excess fluid drips from the diff and surrounding area. Replace drain plug and tighten.
4. You can use a fluid pump to add fluid into the diff or you can add fluid using the clear extension tube that comes out of the bottle lid. The bottle wedges upward enough to get all of the fluid out of the bottle. Add two full bottles then add the third until fluid starts seeping out of the fill hole. Wipe clean and tighten fill plug. Clean entire area of excess fluid.
5. Make sure the drain plug doesn’t have any fluid leaking, clean everything up, lower the car down and you’re done!
1. Jack the car from the driver rear as little as you need to get under and access the diff so the drain plug on the passenger side is at the lowest point. Put a jack stand under the car and get to work.
2. Use a 19mm socket and 1/2” ratchet or impact gun with extensions to remove the fill plug on the driver side and then remove the drain plug on the lower passenger side of the diff. Mine were tight af as it looked like mb used thread locker of some sort. Let fluid drain into an appropriate container.
3. Clean both fill and drain plugs with a rag then wipe excess fluid drips from the diff and surrounding area. Replace drain plug and tighten.
4. You can use a fluid pump to add fluid into the diff or you can add fluid using the clear extension tube that comes out of the bottle lid. The bottle wedges upward enough to get all of the fluid out of the bottle. Add two full bottles then add the third until fluid starts seeping out of the fill hole. Wipe clean and tighten fill plug. Clean entire area of excess fluid.
5. Make sure the drain plug doesn’t have any fluid leaking, clean everything up, lower the car down and you’re done!
12-16-2018, 08:16 AM
#34
MBWorld God!
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2012 CLS63
Nice work gOt Boost
12-16-2018, 08:46 AM
#35
MBWorld Fanatic!
So I finally got around to changing the rear diff fluid for the second (or first) time myself after buying the car. I used the part number listed above for the rear diff fluid which come in .5L bottles from any local dealer or online. You will need 3 bottles, but you won’t use the 3rd one entirely. Before anyone says the car has to be perfectly level, it doesn’t. It is completely fine to have a slight over fill using this method.
1. Jack the car from the driver rear as little as you need to get under and access the diff so the drain plug on the passenger side is at the lowest point. Put a jack stand under the car and get to work.
2. Use a 19mm socket and 1/2” ratchet or impact gun with extensions to remove the fill plug on the driver side and then remove the drain plug on the lower passenger side of the diff. Mine were tight af as it looked like mb used thread locker of some sort. Let fluid drain into an appropriate container.
3. Clean both fill and drain plugs with a rag then wipe excess fluid drips from the diff and surrounding area. Replace drain plug and tighten.
4. You can use a fluid pump to add fluid into the diff or you can add fluid using the clear extension tube that comes out of the bottle lid. The bottle wedges upward enough to get all of the fluid out of the bottle. Add two full bottles then add the third until fluid starts seeping out of the fill hole. Wipe clean and tighten fill plug. Clean entire area of excess fluid.
5. Make sure the drain plug doesn’t have any fluid leaking, clean everything up, lower the car down and you’re done!
1. Jack the car from the driver rear as little as you need to get under and access the diff so the drain plug on the passenger side is at the lowest point. Put a jack stand under the car and get to work.
2. Use a 19mm socket and 1/2” ratchet or impact gun with extensions to remove the fill plug on the driver side and then remove the drain plug on the lower passenger side of the diff. Mine were tight af as it looked like mb used thread locker of some sort. Let fluid drain into an appropriate container.
3. Clean both fill and drain plugs with a rag then wipe excess fluid drips from the diff and surrounding area. Replace drain plug and tighten.
4. You can use a fluid pump to add fluid into the diff or you can add fluid using the clear extension tube that comes out of the bottle lid. The bottle wedges upward enough to get all of the fluid out of the bottle. Add two full bottles then add the third until fluid starts seeping out of the fill hole. Wipe clean and tighten fill plug. Clean entire area of excess fluid.
5. Make sure the drain plug doesn’t have any fluid leaking, clean everything up, lower the car down and you’re done!
12-16-2018, 09:05 AM
#36
Senior Member
The fill/drain plugs are solid metal and don’t need to be replaced unless you round them imo...I didn’t buy new plugs. There is no way these plugs would come out if tightened correctly and they can’t leak since they have a tapered thread. I’m not 100% sure if the fluid was changed at the 2k mile recommendation (I think it was based on oil color) and the tech went ham on the thread lock or it came that way from the factory, which I don’t believe it did.
