Well written article on why ANY trans flush is bad

[JohnG]

The trans on my Mercedes doesn't even have a DIPSTICK! Does anybody know what a trans service costs at the dealership? How do they even know if the trans fluid is low when you do go for service?

 

[nascarnation]

Originally Posted by JohnG

The trans on my Mercedes doesn't even have a DIPSTICK! Does anybody know what a trans service costs at the dealership? How do they even know if the trans fluid is low when you do go for service?

I checked a bit on the internet and apparently you can buy a replacement fill cap with a dipstick on Amazon for 10 bucks to check it.

 

[Leo99]

Originally Posted by nascarnation

Originally Posted by JohnG

The trans on my Mercedes doesn't even have a DIPSTICK! Does anybody know what a trans service costs at the dealership? How do they even know if the trans fluid is low when you do go for service?

I checked a bit on the internet and apparently you can buy a replacement fill cap with a dipstick on Amazon for 10 bucks to check it.

Lots of new cars don't come with transmission dipsticks. Guess they check for leaks to see if you're losing any ATF.

 

[Hall]

Honda has been saying this for, what, 20 years ?

 

[CKN]

No one has ever said a transmission failed because of a clogged filter.

 

[JerryBob]

My takeaway from this Blackstone article of 10 months ago is that ATF should definitely be changed if it has been subjected to excessive heat. https://gallery.mailchimp.com/f6413...c27d276c1fe/August_19_Eng_newsletter.pdf

 

[Kestas]

The first post mentions the problem of exchanging the fluid in Park, even mentioning this precludes changing 50% of the fluid. If you read my often-posted procedure to exchange transmission fluid, I include going through all the gears. When you do, a burst of dark fluid comes out of the transmission on each shift. But this is much less than 50% of the fluid.

 

[JeffKeryk]

Originally Posted by Kestas

If you read my often-posted procedure to exchange transmission fluid, I include going through all the gears.

I am about to service our GS... I would like to read your procedure. Can you point me to it? Thanks!

 

[Kestas]

https://www.bobistheoilguy.com/foru...-atf-flush-vs-drain-and-fill#Post5444047

 

[blupupher]

Originally Posted by 4WD

My next procedure: 1) Drain 5 quarts 2) Pour 5 quarts

Pretty much. If it has a drain plug, make sure it i at the right level, then measure what drains out and add the same. If it has an internal filter, it needs to be changed at some point (sometime before 60,000 miles IMO). Adjust fluid volume accordingly. If no drain plug, drop pan, change filter, then add a drain plug so you can just do drain and fills from then on. My F150 gets a 4 qt drain and fill every 10,000 miles, filter will be changed every 50,000 miles. Scion xB had first drain and filter change @ 30,000 miles, drain and filter change @ 50,000 miles, and another drain and fill every 20,000 miles after that. My Santa Fe will have a drain and fill @ 30,000 miles. Don't remember if it has a filter (don't think it does, but if it does, will be changed @ 50,000 miles). Kia Soul will have a drain and fill @ 30,000 miles, and every 20,000 after (no filter). Never have trusted any flush machine.

 

[double vanos]

Agree with 4WD. Ford trannies (6r80 and 10r80) have fill plug on trans body. Let (in my case) truck sit overnight. Pull plug and using topside oil sucker, suck it dry. Measure old fluid and refill with same amount fresh fluid. Done. Every 30k. Every 150k, new filter.

 

[BHopkins]

Originally Posted by Leo99

Originally Posted by nascarnation

Originally Posted by JohnG

The trans on my Mercedes doesn't even have a DIPSTICK! Does anybody know what a trans service costs at the dealership? How do they even know if the trans fluid is low when you do go for service?

I checked a bit on the internet and apparently you can buy a replacement fill cap with a dipstick on Amazon for 10 bucks to check it.

Lots of new cars don't come with transmission dipsticks. Guess they check for leaks to see if you're losing any ATF.

At least for the 722.6 / 722.9, which are some of their most common transmissions, Mercedes has a very detailed process for ensuring the correct amount of fluid when the transmission is filled. If you put the correct amount of fluid in when you fill the transmission, you should still have the correct amount of fluid 6 months, a year, even years later. Unless you have a leak. And if you have a leak, you should catch it. Drips where the car is parked. Fluid on the underside of the car. If you have a leak, you should address it. And addressing it doesn't mean just keep pouring more fluid down fill tube. So why would you need a transmission dip stick?

 

[Kestas]

Many modern Mercedes models are unique, where the dipstick works in reverse. It measures the level from the bottom of the pan. Many have saved money and made their own dipsticks using a length of old steel cable from garage doors.

 

[JohnG]

Quote

At least for the 722.6 / 722.9, which are some of their most common transmissions, Mercedes has a very detailed process for ensuring the correct amount of fluid when the transmission is filled. If you put the correct amount of fluid in when you fill the transmission, you should still have the correct amount of fluid 6 months, a year, even years later.

I don't know which transmission this has. It's the relatively new 9 speed automatic. It's probably more like the Ford transmission that Double Vanos refers to above. Fill and check plugs in the transmission body, probably no drain either, but that's not uncommon. I suspect the procedure is generally to suck out the old stuff and replace. Just wondered if Mercedes procedure calls for a filter change, and how much their service costs. I'm sure it's a lot. By the time the service is required, I'll be too old to do it myself I'm sure.

 

[CarbonSteel]

Originally Posted by joekingcorvette

I guess I disagree. I just had my 2014 F-150 fluid changed at about 51,000 miles. I pull a boat and believe it's good insurance for the transmission to be serviced. People are quick to buy when they see the maintenance record when I sell. I do have the filter replaced too.

I agree with your thoughts. The 6R80 in my 2010 F-150 had the fluid changed twice in its 160K miles (with about 72K of those miles towing a trailer between 8-9K pounds). When I traded it in, I got an additional $1,500 due to the UOA history that I had on the entire powertrain. Towing is typically hard on a transmission, particularly when combined with heat, so to have never changed the fluid would not been the wisest move. The 6R80 is also "dipstick-less" and has thermal activated switches so the dealer has a special process to change the fluid in those units (the 6R140 in the PSD are similar, though they do have a dipstick). Transmission service is one of the few maintenance items that I take to the dealer.

 

[Linctex]

Originally Posted by ford46guy

And if you do flush, don't even think of doing it without a filter change. He also said trans fail after flushes because of clogged filters. He has seen many.

I do not believe this to be true. I did the *first* pan drop EVER on the 4R75E in my 2008 F150 at 226,000 and that filter was **spotless**. I was shocked at how clean it was (I do use a very large spin-on filter inline the cooler lines) I've dropped the pans on over 100 auto trans in my life, and I can recall only two that had any amount of concern in the filter (and they were severely toasted units) I'd be willing to bet 99% of transmission filters never needed to be changed.

 

[Hall]

Originally Posted by BHopkins

...Mercedes has a very detailed process for ensuring the correct amount of fluid when the transmission is filled. If you put the correct amount of fluid in when you fill the transmission, you should still have the correct amount of fluid 6 months, a year, even years later. Unless you have a leak. And if you have a leak, you should catch it. Drips where the car is parked. Fluid on the underside of the car.

I hope they have a process for checking the level after the fact too, i.e. after customers buy them and take them home. Some owners are oblivious to leaks and may not say anything. You tell me M-B doesn't check it during their "inspection" or routine service ? I actually presumed they have sensors that their diagnostic systems (at the dealer) would use.

 

[RazorsEdge]

More false information. We had the transmission flushed with over 100,000 miles with mileage now currently 360,000 miles on a 96' Crown Victoria.

 

[JohnG]

Quote

I hope they have a process for checking the level after the fact too, i.e. after customers buy them and take them home. Some owners are oblivious to leaks and may not say anything. You tell me M-B doesn't check it during their "inspection" or routine service ? I actually presumed they have sensors that their diagnostic systems (at the dealer) would use.

I did a little research and found that there is a procedure for checking the fluid level in the trans. There is a plug in the side of the trans, and when you remove it, fluid should come out. I suppose several conditions are to be met before this is done, like trans at operating temp, etc. I liken it to checking the fluid level in the rear end of the old cars I used to work on. Came across this: http://assets.mbusa.com/vcm/CAC_RAPMD/images/9Gtronicintheworkshop.pdf After reading some of the stuff in here, such as TWO trans filters, TWO pumps (one electric), and "Golden Yellow GTL" transmission fluid, I've decided I'M NOT TOUCHING IT!

 

[01rangerxl]

GM isn't an expert on transmission longevity, and they can't account for every flush machine procedure, so just saying not to is safer. I think in transmissions that aren't super picky about the type of fluid, it's fine and probably beneficial if you aren't trying to fix an existing problem. My 02 Ranger with the "bad" 5R44E, and tens of thousands of miles of towing, shifts fine at 242K miles. Trans has never been out of the truck, 1 pan drop/filter change ever at 148K, valve body has never been touched. It has been flushed by either a Wynn's or BG machine with their universal synthetic fluid about four times in its life.