ATF: Flush or Change?

[CHRISCHANCE]

I read on here that the securing clip on the ATF filler/dip-stick tube is coloured black when it leaves the factory and subsequent ATF checks by services is replaced with a red clip.

Today I broke off the BLACK plastic clip, which means my gearbox hasn't been checked since leaving the factory 15 years ago! (118,000 miles).

I checked the ATF with a dip-stick and found the level to be OK, but the colour of the ATF is worrying me - it is very dark.

I've bought a servicing kit - filter, oil and gasket but I am now worried that a complete flush with new ATF will cause problems with clutch pads losing grip and valve body channels blocking because the new ATF will clean the system/channels and may cause a blockage.

If I do just a change rather than a flush, I think I am merely contaminating the new ATF with the old in the torque converter, hence the quandary - what to do?

Because the servicing record is up to scratch with MB services, am I to think the ATF is a 'lifetime' item because the existence of the black plastic clip means the ATF has not been checked on any of the recorded services?

 

[merc85]

If you are that worried, Why not just drop the fluid out of the box via the drain pan plug, Then change the filter. Thinks its going tobe around 3.5 lts if its a 5g box. Then top up with new fluid drive a 500 miles say then drain the sump again and repeat until the old fluid is all out?

It should gradually clean the box out that way id have thought.

 

[Petrol Pete]

I read on here that the securing clip on the ATF filler/dip-stick tube is coloured black when it leaves the factory and subsequent ATF checks by services is replaced with a red clip.

Today I broke off the BLACK plastic clip, which means my gearbox hasn't been checked since leaving the factory 15 years ago! (118,000 miles).

I checked the ATF with a dip-stick and found the level to be OK, but the colour of the ATF is worrying me - it is very dark.

I've bought a servicing kit - filter, oil and gasket but I am now worried that a complete flush with new ATF will cause problems with clutch pads losing grip and valve body channels blocking because the new ATF will clean the system/channels and may cause a blockage.

If I do just a change rather than a flush, I think I am merely contaminating the new ATF with the old in the torque converter, hence the quandary - what to do?

Because the servicing record is up to scratch with MB services, am I to think the ATF is a 'lifetime' item because the existence of the black plastic clip means the ATF has not been checked on any of the recorded services?

I had the same on my C55 AMG, no record of ATF change in 117000 miles but the original red cover had been opened by someone in the past.

I just got the ATF and filter changed for piece of mind. Who wants 10 year old fluid sloshing around in a gearbox that has been handling over 350 bhp and 360 fl/lb of torque for the last 10 years ?...not me.

Get it done.

 

[CHRISCHANCE]

Hi Pete, did you do a complete atf change or just the sump (about 4 litres)?

 

[BIG Sean]

what does this job usually cost? I'm needing the Chrysler doing?

 

[vijilants]

Approx £150 to £180 inc fluid.

The fluid is expensive.

 

[bob6600]

Guide is here

http://www.mbclub.co.uk/forums/howto/115863-how-change-automatic-gerbox-oil-flush-722-6-box.html

 

[Petrol Pete]

Hi Pete, did you do a complete atf change or just the sump (about 4 litres)?

Invoice shows 4 litres ATF 3403 @ £8.65/litre , filter £11.10 , seal £8.20 (all plus VAT), the work was done recently and a B service is due very soon. The ATF will be dropped out during the B service and refilled as required. That way the ATF that was left in the Torque converter will mostly be flushed out. After that I will just forget about it.

 

[Petrol Pete]

what does this job usually cost? I'm needing the Chrysler doing?

If you do not insist on a full fluid change (torque converter) you should pay no more than £150 including parts ,labour and VAT.

Subject to where you are in the country of course and if you have a good MB Indi nearby.

 

[CHRISCHANCE]

Hi Pete, I decided to do the same as you.
I bought the ATF, filter and gasket. My local indy did it along with rear discs and pads replacement; engine oil and filter change and replaced all indicator bulbs (bulbs and brakes were MOT advisories).
He did the lot for £200, which I reckon is 1st class because he meticulously cleaned everything and dried it with compressed air.
I bought all the parts and oil etc., so now I'll run it for a while and put the other 4 litres of ATF when I'm ready.

 

[Tuercas viejas]

This is my posture on transmissions (auto gearboxes) that have not been serviced regularly!

The fluid is normally alkaline in nature. Extended drains mean the fluid is moving into an acidic condition.
In any case junk coming off the clutch packs etc is going to coat the circuit board and the speed sensor pads, eventually give shifting issues on the 722 (NAG 1) units (since we are talking MB's here)

As a shop owner when I see a car roll in with the owner wanting a service my first thought is that the unit is suffering a shift condition /problem. That a service will fix it---well maybe yes and maybe NO!
So it gets a test run with a scanner hooked to it looking at live data shift solenoid current ramping etc etc plus of course any stored or active codes.
If it checks out OK my suggestion is to gradually move it back to an alkaline state by partial changes.
Simply because a full fluid swap might just chemically shock the unit and gums, varnishes etc will be stripped off causing drivability problems later on!
Just a suggestion.
Tuercas viejas

 

[ilunn]

This is my posture on transmissions (auto gearboxes) that have not been serviced regularly!

The fluid is normally alkaline in nature. Extended drains mean the fluid is moving into an acidic condition.
In any case junk coming off the clutch packs etc is going to coat the circuit board and the speed sensor pads, eventually give shifting issues on the 722 (NAG 1) units (since we are talking MB's here)

As a shop owner when I see a car roll in with the owner wanting a service my first thought is that the unit is suffering a shift condition /problem. That a service will fix it---well maybe yes and maybe NO!
So it gets a test run with a scanner hooked to it looking at live data shift solenoid current ramping etc etc plus of course any stored or active codes.
If it checks out OK my suggestion is to gradually move it back to an alkaline state by partial changes.
Simply because a full fluid swap might just chemically shock the unit and gums, varnishes etc will be stripped off causing drivability problems later on!
Just a suggestion.
Tuercas viejas

Hi Tuercas viejas what is the likely hood of an ATF fluid change stopping the P0793 (transmission intermediate shaft speed sensor) fault? See also my other post on this problem. Thanks

 

[Tuercas viejas]

Hi Tuercas viejas what is the likely hood of an ATF fluid change stopping the P0793 (transmission intermediate shaft speed sensor) fault? See also my other post on this problem. Thanks

Roger that!!!
I have read your post.
First do you have any other faults like ABS sensor problem? ,. bad brake light switch etc.?

The generic code you have posted is NO signal from the A sensor.
Yes a fluid change might just cure it as the level might be low!
In any case it looks like its coming due for a service from what you have posted.

Normally i use a factory style scanner to see the operation in live data to actually pin point the issue .
The other thing that is important is that there are two types of configuration that I am sure you don't know.
So I have added a link for you to look over and see if you can glean something from it. Saves me writing a diatribe!
Then shoot me some questions.
TV
722.9 7G Tronic Automatic Transmission Problems and Solutions - MB Medic

 

[ilunn]

Roger that!!!
I have read your post.
First do you have any other faults like ABS sensor problem? ,. bad brake light switch etc.?

The generic code you have posted is NO signal from the A sensor.
Yes a fluid change might just cure it as the level might be low!
In any case it looks like its coming due for a service from what you have posted.

Normally i use a factory style scanner to see the operation in live data to actually pin point the issue .
The other thing that is important is that there are two types of configuration that I am sure you don't know.
So I have added a link for you to look over and see if you can glean something from it. Saves me writing a diatribe!
Then shoot me some questions.
TV
722.9 7G Tronic Automatic Transmission Problems and Solutions - MB Medic

Ok thanks Tuercas viejas there is no other codes but that is using a multi car scanner (Autel Autolink Al419) I borrowed I had ordered a better scanner but then got message that they had no stock. On the subject of scanner's apart from the official "Star" machine that dealers use would you recommend any others (what is yours).

 

[ilunn]

Ok was hoping to edit last post but timed out while typing so here I go again.
Having read the info you linked to I think i need to double check what transmission is in my car, is there an online system that will show build spec from chassis number? Also I see the system has the ability to adapt to different driving stiles, could this be why I am seeing problems that the previous owner assures me he had no problems, aside from that the car will be driven by myself and the Mrs we both have different driving stiles mine is steady and the Mrs is erratic (and that's being kind to her). how can any system cope with constantly changing variables?

 

[Tuercas viejas]

Ok thanks Tuercas viejas there is no other codes but that is using a multi car scanner (Autel Autolink Al419) I borrowed I had ordered a better scanner but then got message that they had no stock. On the subject of scanner's apart from the official "Star" machine that dealers use would you recommend any others (what is yours).

Well Yes i have the MB scanner often called a Star
The Autel product you mentioned isn't bad for the money, but it is a DIY style tool so it has limitations. The better Autel tool is a Autel Maxidas DS808 Automotive OBD2 unit.
I also have two Autologic professional scanners , one the Blue Box as it is often called; the other the Autologic Assyst which has pass through type tool with feature for SCN coding through a Drew Technologies J box configuration.
I like the Autologic tools (made in the UK) for grab and go scanning. Once upon a time they were the best tools on the planet!

I have a string of scanners
As stated the Autologic is loaded with Euro makes but the best by far is Toyota/Lexus TECHSTREAM which is for me the BEST! It gives easy access to info, workshop techniques , parts lists , in fact everything going back years; updates , bulletins you name it is there! Basically a tool via lap top base that simply does everything for an annual subscription connect to Toyota's main frame in Japan .
Having stated all that we (as a business) fix quite a lot of Prius platforms (although they don't go bad very often!) They only need simple servicing for the most part so they by definition are not mechanic's friends! They rarely if never need big tear out work to fix! Its collisions & the damage that cause the headaches (excuse the pun) and the Autel tool I mentioned is good for most things even Prius again as a grab 'n go tool!
I must state that Toyota Prius has a soft spot with me since I got a lot of factory training on it and I like automotive innovation having been in this business for so long!
Cheers
TV

 

[ilunn]

Ok Thanks that give me a few scanner options to look out for.
I have found a transmission number for the one in my car its a 722800 00 272113
so I'm guessing its 722.8 and is the predecessor to the to 722.9 that I thought I had. If someone can confirm please. I have tube for the dipstick to go down but still waiting for dipstick to arrive Plan is to check level before I do anything. If it is at correct level would the fault occur just because the ATF is old? If it low apart from not being correctly filled and there is no external leaks where would it go (does it boil away)?

 

[ilunn]

double post so deleted second one

 

[Tuercas viejas]

Ok Thanks that give me a few scanner options to look out for.
I have found a transmission number for the one in my car its a 722800 00 272113
so I'm guessing its 722.8 and is the predecessor to the to 722.9 that I thought I had. If someone can confirm please. I have tube for the dipstick to go down but still waiting for dipstick to arrive Plan is to check level before I do anything. If it is at correct level would the fault occur just because the ATF is old? If it low apart from not being correctly filled and there is no external leaks where would it go (does it boil away)?

I can confirm the application for you tomorrow.
In many cases junk coming off the clutch packs & varnish falling down.& collecting on the conductor plate sensors makes the signal of the impending up/down changes implausible..
I also take a look at the shift solenoids since they have a spike like contact pin(s) which when tightened down bears onto the the printed circuit of the conductor plate. Any deformity will interrupt the passage of current. Of course the connector socket does need to be replaced when the unit is serviced. Note on some if not all models a small drain plug can be found on the back side of torque converter and if it there I always drop the oil doing a full change.
All the best
TV

 

[ilunn]

please tell me that a 1/8 DIA flexible plastic rod would hit something solid before hitting the bottom of transmission sump!! is there some lip or something in bottom of dipstick tube that it could snag up on?