Jiffy73

You
I have a Mercedes-Benz ML350 4MATIC 2011 that vibrates at around 30mph. Doesn't do this at lower or higher speeds. I have had tryre balancing, rim repair, transmission and transfer case fluid changed but it still happens especially on first start of the morning. Disappears during the driving day only to start again in the morning. Does the transfer case need replacing? What else could it be, please

expl0rer

What gear are you in when the car does this? Have you tried pulling codes?

How far below and above 30 mph is the vibration noticeable?

I would try downshifting and maintain the same speed (do you have paddle shifters?), so RPM will be higher. Do you feel the vibration still?

Upshift to return to the initial gear (note which gear it is from earlier). Is the vibration still there?

Put the gearing in D (on my X164 I long-press the right paddle shifter). Speed up some so your car can shift into the next gear. Watch the tachometer to see when that happens, if you don't feel it generally. Downshift to return to the "vibration" gear and let the car reduce speed (do not brake!) to 30 mph. Any vibrations at 30 mph?

I would perform the same sequence with the car warm.

Let us know your results.

Jiffy73

Thanks s@expl0rer for responding so promptly. Just saw this message and have been out all day driving and so will attempt your steps tomorrow on cold start. I don't currently know the gear where the vibrations happen as I have always driven automatic and never used the paddle shifts. I will let you know results shortly. Thanks again.

Jiffy73

Haging having never used paddle shift before, took me a few tries to get it right. I noticed the vibration between 30mph and 40mph in gear D4 @ 2250 - 2500rpm. On deceleration however, the vibration is not as much. However I find that after fiddling about in manual mode the problem overall isn't so noticeable. Maybe car has warmed up.

Will try again with another morning cold start in paddle shift mode
I don't know anything about diagnostic codes

expl0rer

Try D3 hear as well @ 2250-2500 rpm. Note if the vibration is there, more or less noticeable, or not present at all.

In D4, does the car upshift to D5 around 2500 rpm? If yes, what about upshift from D5 to D6 at 2500 rpm? Any vibrations?

About codes: having a code reader is handy as you can use into the ODB2 port and pull codes for various modules. It would help with diagnostics and you could see if the transmission has any codes and issues. The check engine light will not necessarily light up for codes/errors n the transmission module.

There are numerous code readers on the market. I personally use the iCarsoft MB2. Reasonable cost and you can't mess anything up. It only reads codes, you can't perform adaptations with it. There are other readers at various price points which would allow for adaptations. There are several threads discussing "the best" optoons. You can decide which is best for your level of mechanical inclination.

Jiffy73

Thanks for your help. I don't have a diagnostic machine. Maybe will get one in the near future.

​​​​​​So I tried again today. The car doesn't vibrate in D1, D2, D5, D6, D7. I manually shift the gears up around 2250rpm because I personally feel it's ready to change based on engine sound. On keeping the car on D3 on 35mph, the car is at 2500rpm or higher and I feel the vibrations then and when I shift to D4 it vibrates at 40/45mph at 2250/2500rpm in similar way. In both gears D3 and D4 the deceleration vibration is not as noticeable but is still there. Does this help figure out what's going on in any way, please?

expl0rer

So when you downshift from D4 to D3 and maintain speed, the vibration is there, right?

That leads me to believe vibrations could be related to transmission mount bushings or transmission itself.

When was the last time the transmission fluid was changed? How many miles on the car?

The 722.9 gearbox should have the transmission fluid changed at interrvals, even though MB only recommends it done once at 60000 km, IIRC. If it has not been done at all, I would start with that. There are resources here and you tube to outline how to do it if you DIY, or I would take to MB or a good independent MB mechanic. It is not a simple drain/refill. You need to pump the fluid in the transmissoon at a certain temperature of the transmissoon and it is an involved process. Also, need to replace gasket, filter, bolts, drain plug, and clean the pan magnets/inspect for metal shavings. If no shavings are present, that's good. If there are shavings, depends on how much, it could indicate that your transmission may need more attention or repairs.

Also, there are some who would say to only replace half of the fluid if the vehicle is high mileage and the fluid has not been changed. Then, after some time do it again with another 5L change. All new fluid on a high mileage transmission may cause other bigger and more expensive problems with it.

You can have the codes read at a mechanic as well, but that will have a diagnostic cost and you might as well get a code reader for yourself to save on paying for diagnostics.

Jiffy73

@expl0rer The transmission fluid was changed in July 2020 at 176,000 km (110,000 miles) and a "B" Service at 179,000 km (112,000 miles) in Dec 2020. So you can tell I don't drive much as I work mostly from home due to COVID19. Car mileage is currently still under 181,000 km. So

Then only this Saturday just gone 11th Feb 2021, I had transfer case oil changed.

Yet this problem still persists. I'm really trying to do what I can to keep the old girl running as I can't get a new car now. I think the transmission mounts is probably something to look at. And will see about getting that diag tool too. Will keep you posted with developments.

Thanks again.

Jiffy73

@expl0rer The transmission fluid was changed in July 2020 at 176,000 km (110,000 miles) and a "B" Service at 179,000 km (112,000 miles) in Dec 2020. So you can tell I don't drive much as I work mostly from home due to COVID19. Car mileage is currently still under 181,000 km. So

Then only this Saturday just gone 11th Feb 2021, I had transfer case oil changed.

Yet this problem still persists. I'm really trying to do what I can to keep the old girl running as I can't get a new car now. I think the transmission mounts is probably something to look at. And will see about getting that diag tool too. Will keep you posted with developments.

Thanks again.

expl0rer

Nothing wrong with keeping the old girl running. I have a 2010 GL and know all about keeping her up to date as best as possible with a small dose of experimentation - how long can I push a component before it's really time to get a new one in its place. Transmission is not one of those components, definitely!

Was the transmission fluid changed before the 176000 service? When?

Looks like they used 6 L of fluid (assuming the $48 container on the invoice is 1L). It does not look like they drained/refilled the torque converter, otherwise they would have used more than 6L of fluid. That's ok, and suggested practice around here if the fluid has not been changed at all, or above 50-60000 miles (80-95000 km). If you have, however, been doing the fluid change regularly, then a full transmission fluid change is ok to do. I wonder why the shop did the partial change. Perhaps someone here with W164 can comment if the torque converter has a drain plug or not. Some do not, I don't know which ones, though.

You mentioned transfer case fluid replacement on the 11th. Did the vibration start after this service? If that is the case, I would contact the shop and advise them of this. They should at least take the car in and diagnose it. You should be able to take a copy of the diagnostics home. If they suggest any service, you can turn it down for the time being, of course, unless they offer to do it free of charge I am doubtful of the latter, but you never know. I am not sure if the vibration is related to the transfer case fluid service. It does not seem like it would be, but you never know.

Jiffy73

Thanks @expl0rer
I know she's old but before this car, when I lived in the UK I had a 2010 ML300 (Blue-Tec Turbo Deisel) (Marcella) from April 2015 up until Oct 2019 and I never had this transmission issue at all. So I have an idea how good and nice the ML can be. Although, Marcella was only 70,000 miles when I had to sell up and move to the UAE and took over this "new" old girl (Esmeralda) from a work colleague that was leaving Dubai when the pandemic initially set mid last year.

I don't know when the transmission was changed before 176,000 km because I took over the car at 175,000 and the service history was not well kept by the previous owner and based on this I got the car at a very low price. The car initially had slow-to-shift problems and a very audible shudder. I had to replace engine mounts, gear mount, front and rear axle boot, spark plug, ignition coil, front upper and lower arm bushes. New tires and a rim repair. These efforts to restore Esmeralda to glory, along with the transmission fluid change seem to work a treat. Everything was ok until mid-Jan this year when I started noticing the vibrations that will start in the morning and disappear in the day (everything described in the initial post) It was then I did the transfer case fluid replacement on the 11th of this month. It seemed to improve a bit but not entirely remove the issue and this is why I am wondering if the transfer case needs replacing altogether.

Anyway, she's back in a garage that specializes in gear boxes now and I have asked for a full inspection and and diagnostics. Will keep you posted.

expl0rer

No problem. Hopefully the diagnostics will produce some helpful info. I'm sure there will be some feedback from others too. The more info available, the better.

I've taken on the habit of naming my cars from my wife. She did it before we met, and still does. The current beast on wheels is Heimdall, Hal for short. Hal can be a little temperamental, as one could expect from anything bearing the name of a Norse god. But we make it work.😀 The name fits well.

The W164 can be reliable as long as they're cared for properly. Although the diesel motor is a weak link and gives owners some extra headaches and expenses. You've put quite a bit of maintenance into Esmeralda since you've owned her. Keeping her up-to-date is necessary and hopefully she'll serve you well on return.

Looking forward to hearing what the shop says.

Jiffy73

Marcella wasn't actually so bad. Mostly all she needed was a yearly service and tyre swaps for the seasons.
The only big expense was when the oil cooler seals went.
I cursed MB for its placement near the turbo. The part was cheap.
It was the labour charges that could have killed me but then I had a good independent MB guy that did me a proper solid on that.

Good habit from the Mrs! Car-naming, I believe, creates an extra special bond, for me at least. Calling them "the car" is just not good enough.
Hal sounds like you must "drive him like you stole him" at ALL times

Esme had a vacuum line leak, which is what the latest diag says according to the garage. This was a quick fix of AED200 (USD50)
They also said that transmission is in good order. No fault codes there. They checked mounts and tyre balance. All ok.
They had her overnight and did the test driving in the morning and recommend going on a long drive to get all the fluids going as
I have only driven under 20km since I replaced the transfer case fluid.
They say come back in a week if the situation doesn't improve or gets progressively worse.

expl0rer

Good that they found d a vacuum leak and fixed it. For relatively cheap.

I hope that their recommendation to drive the car for a longer period wouldn't deteriorate anything major and expensive to repair later. But they have more experience than me in this department so I suppose you have that on the table as an option. I would be keeping a close eye on D4, and just as much on D3 and D5. I don't know that your RPM will be high enough to drive 30 mph in D5 but I woild give that a go. Also cycle through the gears when the car has warmed up, using the paddles. Move up and down D3-D5 and even all gears for a bit.

I wouldn't get in the habit of downshifting all the time. I had to get myself out of it, as it wears the transmissoon more than using brakes to slow down. It's cheaper to replace brakes. That was advise I took from fellow members here.

Hal is too heavy to drive like I stole it lol although it goes quite well in a straight line.The name sort of came to me because of our senior dog. Heimdall is the guardian of the bridge between the lower and upper worlds in Norse mythology. I've tasked Hal, whom I sometimes also refer to as "the beast" or "the tank", to do that job in our family 🙂 You're right, the connection is a little tighter with a name.

E55Greasemonkey

My ML350 4matic with 172k miles has a similar problem, only on first drive of the day for a few minutes. I can feel the vibration in my drivers bottom seat. It's more of a hopping tire shake and not a fine vibration like the transfer case vibration on full lock turns. I believe it's the tires flat spotting after sitting overnight, but I'm not 100% sure.

Maj. Dundee

Check both driveshafts for movement.

Jiffy73

Thanks @E55Greasemonkey Hmm, tire flatspotting is also interesting. And it's in the driver's seat that I feel the vibration most. My tyres are Kumho Crugen HP91 and I live in the UAE where it's mostly warm weather. We're in winter now where temperatures range between 18 C ( 65F) and 26C (78F) degrees. Could the weight of my car cause flat spots overnight? What can one do to mitigate?

Jiffy73

Thanks @Maj. Dundee ! I hear you. But if it's driveshaft, wouldn't it be more consistent and not disappear in the day?

E55Greasemonkey

One way to test my theory is the put the car on jackstands overnight- all 4 corners to avoid flat spotting of the tires. Then lower it back down right before you are ready to drive it for the first time that day. I have new, but cheap tires on mine. However, even my E55 with Michelin Pilot Sports will have this temporary flat spot vibration, but it tends to stay parked a week or more between drives. You may be able to try parking on different surfaces overnight and see if anything changes, such as grass or sand instead of concrete.

Jiffy73

That's my hope too! I won't leave it for a week though. Few days max. 50km of driving. And if it doesn't improve, will take it back.

I will give this a go when the car has warmed up and update you

That won't be a problem In all my life driving automatic, I have never used the paddle shifts until your recommendation. And even then, had to check a YT video to learn how to use them so I don't do up or downshifting at all. I keep it in 'D'. There are no hills here in the UAE. Just motorway driving.

Nice one! I'm sure Hal does the job he was named for spectacularly and has a befitting loud horn too!!

Jiffy73

Thanks @E55Greasemonkey ! I don't have any jack stands to try out your first option.
Maybe parking overnight on a sand patch ?? I live in the Middle East. Plenty of sand around here

Jiffy73

@E55Greasemonkey Will increasing tyre pressure to 35psi reduce flatspotting? Recommended pressure in the gas flap is 32psi.

E55Greasemonkey

I run 38psi

Jiffy73

UPDATE: So I have driven the car now for some days now and the vibration has improved (as in becoming much less). I also increased tyre pressure to 35psi and this combo appears to be working. Still have the initial morning rumble but disappears in a couple of minutes but it's nowhere near where it used to be.
Thanks to you guys for your valuable inputs!

E55Greasemonkey

I'm happy to report my vibration at 32mph has been fixed by replacing the rear driveshaft with a new OEM unit. I verified the problem by putting my ML in Dyno mode, and having someone running the car in drive on a lift. Watching the center support bearing from underneath you could see the side to side vibration as the car reached 32 mph on the speedometer. Speeds above and below showed little or no movement of the center support bearing. My ML is now riding incredibly smooth, even noticing a difference at speeds above 50 mph.