ML AUTO BOX FLUID CHANGE

[panason1c]

I'm considering changing the Auto/box filter and fluid on my 2001 (facelift) ML but i've just spoken to someone at Andy Gayle (Independent Merc specialists) and he said that the 'electronic' boxes DO NOT need fluid changes....he was quite insistent on this matter...SO, after reading many previous posts on this subject is there a different point of view regarding the 'electronic' and 'non electronic' gearbox oil changes?

 

[Arnie]

Well, the recent auto-boxes have a "lifetime fill" synthetic oil and this was partly done to spare potential errors and mess-ups during servicing. These fully-electronic 'boxes are also a little more tolerant to dirty oil, as they don't have the labirynths of micro-channels that used to make up the hydraulic pressure-sensitive control circuits. Instead the valves and solendoids are micro-processor controlled.

The debate is to whether such a "lifetime" fill is actually good for longevity of the 'box or whether it would be advisable to change the oil (expensive and special oil- not the usual Dexron III), say after 60,000 miles. Some people think so while other's don't believe it is necessary.

An MB dealer will change the oil if you insist and a refill is about £100 + filter and labour.

I guess it depends on how long you intend to keep your car. Anyway, given that MB don't seem to be building cars designed to last as long as they once did, maybe the gearbox oil should not be of great concern.

 

[landover]

No need to change the oil mate.unless it is contaminated .

 

[guydewdney]

i can testify that oil changes are necessary - ive broken two boxes so far - the second one due to wear and tear on a major bearing inside it..

but that was at 160,000 miles

 

[panason1c]

Well, i've got the new filter, gasket, oil and dipstick for the auto box, i've also got a new 'seal' for the dipstick tube cap (total cost £77)....my question is....how do i remove the sealed dipstick tube cap?...does it just pull off or do i have to remove the plastic locking plug first?..i've not really studied it yet, i will look more closely when i get round to doing the job but it helps if someone knows the answer.
Cheers

 

[MB partsman]

be very carefull when you do the filter change, i have heard of gearboxes going wrong after oil changes.......
as Andy Gayle says best left alone, unless you REALLY know what your doing....... leave well alone!

 

[panason1c]

Just found this post (below) from the US website, makes interesting reading.........



Transmission & Transfer Case Fluid Changed

Ok, bit the bullet. Original owner of 99 ML320 with 75K miles - and want to keep it for a while. So I talked with a MB Master Mechanic (he has a 99 ML320 as well) and he also did a transmission and transfer case fluid change.

Was quoted $400 to do the change, but in the process, discovered that the transmission lines were leaking - so total bill was $1000 for everything. Dealer goodwilled so much previous work I figured I'll pay this one.

The ML is fully paid for, and I love this truck, so I really don't mind these maintenance investments...

But anyway, back to the fluid change - the so called lifetime fluid was completely black and very thin. The mechanic said the reason they call it lifetime is that these days 100K Miles is considered lifetime.

The ML shifts noticeably smoother, and am glad I got it done - peace of mind frankly. Highly recommended!

Anyway, the procedure for fluid change is rather complex - and dealer has to use a special dipstick...Anyway I highly recommend you get your transmission fluid changed if you are running either 100K miles or it's been the same fluid for the past 5 yrs or so....

 

[guydewdney]

consider this...

there are sets of clutch plates in the gearbox. clutch plates, by definition, are a friction material. they must slip againt the driven or plain plate in order to provide a smooth gear chage. thats how they work.

every time it changes gear, the clutch pack will slip a bit. causing (a very slight) bit of wear. Where does this material go? into the oil. OK, so some of it is removed by the filter, but not all - its very fine...

So - now you have oil mixed with a friction material sloshing around in the box.

for 100,000 miles?? Madness I tell you.

In the 'early' electronic boxes theres a bush (brass or phosphor bronze) connecting the two main input and output shafts together. Unless the box is in 5th or D and stationary, this bearing is spinning. In mine it went pear shped, and let the shaft flap about, wrecking the box.

In the later (I think post 99) boxes this bearing is a 'proper' needle roller bearing.

THREE replacement boxes had to be bought, and sent back in order to find one that was in good nick, and the same bearing wasnt 'gone'.

In the normal course of events, this would have cost me 1500 to 2000 quid to be fixed... long story, but George Fraser in west london did me a very very good deal...

 

[bigt]

oil life

The bottom line is that oil just does not last forever, it is subject to heat, shear stresses, atmospheric moisture, debris from worn moving parts etc etc etc. Infinite lifetime oil is just a load of cr*p, it defies the basic laws of physics. MB should be brought to task over this claim!

 

[Arnie]

The "lifetime" oil is a very much higher grade of synthetic oil than the normal Dexron-type oils. It is therefore less prone to oxidisation and deterioration. However, there is an additive pack which gives the base oil its anti-friction properties and which determines its shifting qualities. This addititive pack is also prone to deterioration. Any wear debris in the oil should be collected by the filter but it will not harm anything to change the oil after 60,000 miles. Most synthetic auto-transmission oil manufacturers advise on a 3x extension of the change interval compared to ordinary fluids. (Between 45k and 90k miles). As mentioned, the word "lifetime" may only be relevant to the warranty period of the car, and many buyers of new cars tend to change the car every three years so as long as the oils can survive this period...

Still, it's not only MB who have done this and many others, including BMW now use these oils.

The oil-change process for modern gearboxes is complicated, requiring exact temperatures and levels to be measured accurately for the gearbox to work properly, which is another reason for wanting to miminise the requirement.

some articles:
http://www.1st-in-synthetics.com/trans_fluid.htm

http://www.1st-in-synthetics.com/articles.htm

 

[panason1c]

Arnie wrote........
"The oil-change process for modern gearboxes is complicated, requiring exact temperatures and levels to be measured accurately for the gearbox to work properly, which is another reason for wanting to miminise the requirement."



With respect Arnie........surely it's not too much to expect that a trained mechanic can drain a gearbox and then fill it up to a dipstick mark at a given engine temperature?.......what's complicated about that?....maybe MB dont have a lot of confidence in their mechanics...oh, sorry.... we refer to them as 'technicians' these days?

Or is it that replacement gearboxes by MB are a 'good earner'?

 

[guydewdney]

cant be that good an earner - i asked MB UK to see if they would do a goodwill thing towards repair of my car - they said they could give me a 10% discount on the parts (700 quids worth at least) - BUT i had to have the work done at a MB garage - to which i replied that the garage refused to do the work as they wernt trained on this... she was confused...

MB do not repair gearboxes - as they are sealed for life. yet they list and will sell you parts for your gearbox... does this make any sense? Oh - and the parts were on the shelf..


hmmmmmmmmm

 

[landover]

Best thing to do is drive them till you have a problem.Why go looking for one.If it is filled for life then leave it.

 

[guydewdney]

Best thing to do is drive them till you have a problem.Why go looking for one.If it is filled for life then leave it.

because - by the time theres a problem - somthing is wrong / worn.


imho

 

[landover]

Best thing to do is drive them till you have a problem.Why go looking for one.If it is filled for life then leave it.

because - by the time theres a problem - somthing is wrong / worn.


imho

Correct. Then you have something to fix and post on the forum.

 

[numbnuts]

It?s your car mate if you feel like changing the oil then changes it. Just make sure you have a spare couple of grand just in case it doesn?t work out as planned. :lol:

 

[dieselman]

Best thing to do is drive them till you have a problem.Why go looking for one.If it is filled for life then leave it.

because - by the time theres a problem - somthing is wrong / worn.


imho

Correct. Then you have something to fix and post on the forum.

But then thats sticking plaster servicing.

If you perform preventative maintenance your car will be a lot more reliable and cheaper in the long run.

 

[dieselman]

It?s your car mate if you feel like changing the oil then changes it. Just make sure you have a spare couple of grand just in case it doesn?t work out as planned. :lol:

But then if you don't, you'll definately need the money because the box will go for sure.

In reality there's no such thing as a no maintenance piece of machinery.

 

[panason1c]

Just completed the auto box oil change, the old oil was very black and the filter was very sludged up with lots of 'gunge in the sump...........also, using the 'workshop' MB dipstick prior to draining showed the oil level to be very low by about one litre, on the relevent temperature related dipstick mark....(the box was at full operating temp')...
The only problem is that there was no torque converter drain plug, (there is one on earlier models apparently), so i will drain and refill the box again in about 10,000 miles to 'dilute' any old residual fluid down.
Glad i did it for peace of mind......if anyone has any doubts about changing this 'for life' fluid then you should see the fluid and gunge that was drained from mine..there is no doubt that this fluid DOES need changing (i would suggest 60k intervals) in the interests of preventative maintenance.

 

[kaleem]

panason1c
Did you feel noteable difference in the drive and gear shifts?
Did u have jerks or irratic gearchange before the change?
Thanks the feedback.