superpop

My MY2015 S550 4Matic with 43K miles is due for the transmission service at 5 years so looking to get this done. What is the verdict on flushing vs service with pan removal and new filter/fluids? Flushing seems better as it replaces the fluid but I am concerned about disturbing the trans too much as I have heard the detergents can break stuff loose and mess with the valves and such. Merc dealer wants to do the flush. What is the best option.

Katie22

Herd many mechanics say dont flush for the reason you listed.

As far as doing the remove pan and change filter I have done it and its pretty straight forward. You can buy a kit on Ebay for your trans that included filter, pan bolts, and the correct Ravnol fluid and standoff. All that remains is the filler adapter for a few dollars and a scan tool to show trans fluid temp.

I would say one thing though. I think you could get by with no scan tool if you took the time to measure exactly how much fluid came out and put the exact amount new fluid into the car.

Jud Chapin

Regarding the tranny temp check, I’ve talked to a couple of MB techs and they say they never check it.
They just put in what was removed as Katie suggests. Actually, tho, you can use a temp scan gun which are pretty cheap now. And they’re nice to have around for checking coolant temps, a/c vents, a/c leaks, etc.

blackbullit

Definitely do not let dealer flush the transmission.

My dealer did this to my E320 back in the day. Blew out the transmission seals & destroyed transmission by causing a leak. $6000 to repair...

Drop the pan & service the old fashioned way.

chassis

Dealers have propagated the myth of "sealed for life" transmissions forever. This is bunk. Any oiled mechanical device needs its lubrication changed.

Mercedes spells out a transmission fluid change interval, so yes it should be done.

The service includes a filter change, which requires the pan to be dropped. The WIS procedure also calls for the torque converter to be drained, an important step. This service is not a "flush".

A "flush" is a pressurized oil change that replaces fluid in the cooler lines and cooler. This is rare because of extra time and effort, and does not appear to be called for in WIS.

zenderV8

I think 2015 model will be equipped with 7G plus. As well for sure there is at least one video on YT which inc. the trans oil change along with torque converter oil drain. Soon I will have to do the job as well , most likely in December but before that need to buy WIS

Katie22

Tidbit I brought a 27mm socket so I could turn my engine over by hand so I could position the drain on the torque converter. After a half hour of doing this it became clear that on my 2016 Maybach there was NO drain on the converter. Needless to say I have enough trans fluid to do the service again at 100000 miles.

You can buy WIS on ebay for around 8 to 19 dollars.

Here is an example of the service kit you can buy to do the job. Missing is the filler adapter.
http://www.blauparts.com/repair-part...caAi56EALw_wcB

and here is the filler adapter

cetialpha5

You can pick up a case of ATF 134 FE from a Shell distributor. The local one near me charges about $83 for a case of 12 quarts.

https://www.shell.us/business-custom...r-locator.html

superpop

Went to the dealer and they clarified that the service includes new filter, fasteners and fluids. No flush. Cost is $515.00 plus I have a $150 coupon for MB service so cost will be around $365.00. Worth it for the peace of mind of having it done at the dealer.

chassis

Good news @superpop . I think my dealer charges north of $600 for this service for a 7G-Tronic and I haven’t once in two years of ownership seen a coupon. I am in a small-medium size one-dealer city with no serious independent shop or competition.

cetialpha5

You could also check into the cost of a service package. They include the transmission service and spark plugs if they're due. It's a good value just for that. Otherwise it's not worth it. I think you can buy it up to 80k. Depending on when the spark plugs and transmission fluid are due, it could be worth it to get a 3 pack. You can't use those $150 off $300 service coupons on those packages though.

bkdc

Say NO to pressurized tranny flushes. My dealer did the 7G tranny / filter replacement at 64K miles. It was included as part of my prepaid service plan that I paid for with the CPO purchase. I’d always thought that a tranny service would be charged extra, but this makes prepaying for service a reasonable deal if the dealer charges that much for a 7G tranny service. Not that it was needed, as I did the service at home at 45K miles anyway. . Now I guess I have an extra-clean transmission given that the torque converter can’t be completely drained. And yeah the dealer replaced spark plugs at 54K miles included with prepaid service. Since then I ended up replacing two dead ignition coils at home.

The hardest part of the W222 7G is dropping the contraption which holds up the exhaust pipes. Otherwise, you cannot replace a external-torx screw (single-use) when you drop the pan. They are very large bolts holding up the exhaust. Since then I obtained at a complete set of Williams impact sockets which which extend to even the most massive sized bolts.

chassis

@bkdc Did you mention any background on the reason to avoid flushing the cooler and lines? I didn’t see it, apologies if it is my oversight.

2012 merc amg

As I remember the trans service on the 2015 S550 is not due until 60K miles, at least that was the case on my old car. I thought it was 40K and after some research it was listed as 60K miles.

chassis

722.9 in the W166 is a 60k mile transmission fluid and filter change interval.

Katie22

Oh and another tidbit. If you have WIS on my car it said to remove the pump (used for start stop feature) at the front of the pan. I DID NOT have to remove this pump to get the pan off. Nor did I have to remove any exhaust components. Mind you this was for the v12 car but the v8 might be the same.

Katie

bkdc

I also didn’t have to remove any pump. It is possible to drop the pan and slide it over the exhaust bracket but this leaves a single external torx bolt (single use) which has to be reused and not replaced. A small ratcheting 8mm wrench (or a ratcheting e-torx wrench if you can find one) can be used to undo the bolt to drop the pan, but it will be trapped for reuse without replacement. To replace that last bolt, the exhaust bracket needs to be dropped.

Katie22

I recently changed out the fluid on my AMG GTC. Interestingly the car has no filter but within the transaxle there are TWO fluid reservoir and a set of not difficult but exacting procedures to follow. Doing that job was notably more involved than the S Class trans fluid change. Come to think of it I would say the biggest time consuming jog I have done on these cars was change the 24 spark plugs on the Maybach. That took a few hours because I was extremely methodical while doing that one.

Bravo to anyone here doing their own work. The cars are not that difficult to take care of.