Rough Gear Changes - Changing ATF

[Dano]

Hi all,

As is the norm for my posts, some background followed by a question.
You may wish to skip straight to the footer

Background
The hard gear change was once a rare occurrence. Now it is becoming more frequent.

My W208 has done 96k and I have no way of knowing whether the ATF has ever been changed. It needs to run for another two years so I'm taking no chances.

I phoned round 4 independents today (all shall remain anonymous for now) and I got wildly varying pricing.

£70+VAT through to £160+VAT

Most but not all mentioned the Oil, many saying that was the most expensive part.

The cheapest indie said "We will use Dexron 3". I'm really unsure whether I should be attracted or repelled by their low price!

The other indies said we will only use the recommended oil, or similar words

The question

a) Is this Dexron 3 the correct oil for my auto? (W208365)

b) What work and parts should I specify to makes sure I get maximum benefit from the job? (eg) drain this, change that?

Reading other posts i can see different people have a variety of different parts replaced, All under the generic title of "ATF change"

All advice warmly welcomed,

-- Dano

 

[Ian_C]

Ian B walker did my E55 fluid a while back. The price was over £100, but really do you want to start scrimping on ATF fluid. Price was fluid, plus labour. very honest.

Give Ian a call at W124works, he's not that far from you.

Ian

 

[SilverSaloon]

the genuine merc branded ATF fluid will come to around £80 for your gearbox.

then i suspect about an hours labour.

if the car has a drain plug for the torque convertor - make sure they drain it.

good luck

 

[Adam230K]

If your handy you can do it yourself, it takes some time but isn't hard to do overall. If you have a Hayne's manual handy it'll help with a few things too (i found).

 

[Dano]

Thanks for the responses so quick. I will definitely not compromise on the fluid. I have used Mobil1 0w/40 since I got the car. No point cutting corners if longevity is my goal.

Having said that I spent over £500 on the car in January, so I’m doing that bit more price research!

Some more digging reveals Dexron 3 is suitable for 722.4 Autos and maybe not for 722.6. Unfortunately I've not found anything definitive on gearbox oils for my specific model.

 

[Ian_C]

A man after my own heart. Cheers Ian

 

[lynall]

Iirc oil is on e bay mercedes gearbox oil.

Dont forget filter as well, i rung our local auto gearbox place and they said they use dextron 3 in everything and have no problems.

Wifes c320 has atf 3 in the gearbox and runs a treat if anything its better than mine.



Lynall

 

[BlackC55]

Dextron III is not good enough according to the MB literature.

I charge £165 including a flush out (many garages don't do this) and a new filter and sump gasket.

I only use the MB stuff 'cos I know its right.

 

[vijilants]

False economy to use anything but the MB fluid and also getting the job done properly.......An auto gearbox is a very costly item to replace just for the sake of saving a few pounds on oil and the oil change.

 

[Smiley]

You should have the filter changed at the same time - this involves removal of the sump pan. Use a good quality ATF like Mobil.
Dexron 2 and 3 are spec levels not a manufacturer and I am pretty sure (but double check with MB) that Dex 3 is right for your car. Get the new filter from MB and check the price of their ATF but don't pay a big premium over Mobil ATF. Get a decent indi to do the job who has done it before and knows what they are doing - otherwise you will get some moron who overtightens the sump bolts and you will lose your new fluid through leaks.........or does it outside and bits of grit blowing around......
it's a job worth paying a few quid extra for someone careful, tidy and clean to do it.
You could also check the MB dealer price to do the job - you may be surprised that it is not too much more than the indi.

 

[Smiley]

Dextron III is not good enough according to the MB literature.

I charge £165 including a flush out (many garages don't do this) and a new filter and sump gasket.

I only use the MB stuff 'cos I know its right.

Do they give a different spec?

 

[jaymanek]

Autodata note that nromal ATF is fine for a W208...

I personally use Dexron III in all of my cars, modern or classic.

For customers cars we always give them a choice.

The MB stuff is expensive and Dexron III is to MB spec, infact even Dexron II is to spec for most models.

 

[Smiley]

Autodata note that ATF is fine for a W208...

I personally use Dexron III in all of my cars, modern or classic.

For customers cars we always give them a choice.

The MB stuff is expensive and Dexron III is to MB spec, infact even Dexron II is to spec for most models.

Thats correct - the Dexron 2 is OK in my old 4 speed auto in the W124 - but the Dexron 3 is backwards compatible anyway (and I think is the same price ish?) and apparently gives smoother shifts - dont know if that is true or not. More important to get a proper careful job done than worry about the make of the ATF too much.

 

[jaymanek]

Exactly... dont drain the old stuff out properly and the whole object is defeated...

I let mine drain for ages.. usually leave it for over an hour to drain...

 

[kth286]

A good vacuum is essential for smooth aut changes, so perhaps yours is getting bad (split pipe etc)

 

[Dano]

Thanks for the feedback guys. Lots of great info.

Looks like the jury is out on Dexron3. Some affirmatives and some negatives on here.

One indie I spoke with said there is no torque converter drain plug on my model/year. He thinks it is impractical to completely flush the system.

More digging suggests one option to disconnect the oil cooler pipe and turn the engine over.

Seems like I should mentioned checking the vacuum, whatever that means.. (i have mental images of an upright hoover)

I'll let you know how I get on... prices, feedback etc. Many thanks

 

[Dano]

Experimental driving suggests the hard changes tend to happen during a change to a lower gear (usually when applying the brakes).

I acknowledge the referral to IBW at 124w. I spoke with Ian and I was convinced of his excellence, but in the end it comes down to convenience.

Partsspecialist mentions "Bolton Motor Works", Farnworth in a thread.

They are the nearest specialist to my current work location so I am taking it there.

The plan is a two phased approach; (1) a drain and fill. Followed by two weeks of driving, then (2) a further drain and fill, new filter, new gasket

Thanks for the advice,

-- D

 

[Ian_C]

Just had my ATF changed at PCS. It did improve the gear change, into a much smoother affair.

CLK 320 - 94000 odd miles.

Ian

 

[kth286]

Dano

I mentioned a bad vacuum in post 15.

You now state the change is worse when braking, which does indeed point to a vacuum problem.

Brakes work using vacuum in a big way, and so when you brake you will be depleting what vacuum is available away from the gearbox need for vacuum.

So, to avoid further excess wear to your gearbox through harsh mechanical shock, just get the vacuum system looked at first and forget the oil change for the moment.

It is very easy and quick to check the car vacuum system to ensure it is at the appropriate spec. or not.

At least then you will know the problem instead of going around the houses with oil change etc.

 

[Dieselman]

I mentioned a bad vacuum in post 15.


Brakes work using vacuum in a big way, and so when you brake you will be depleting what vacuum is available away from the gearbox need for vacuum.

So, to avoid further excess wear to your gearbox through harsh mechanical shock, just get the vacuum system looked at first and forget the oil change for the moment.

The 722.6 gearbox doesn't use vacuum for shift smoothness, it's all electronic.

As far as brakes and vacuum, the servo bleeds vacuum when the brakes are not being applied and stops leaking it away when they are, hence gives vacuum assistance.