Hard downshift when braking, especially in W mode
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2007 ML350
Hard downshift when braking, especially in W mode
2002 C230K Sport Coupe, A/T, 98k, fully serviced.
When doing moderate (60%+ braking, and in W (winter) mode, I get a single THUMP from (what feels like) the rear differential as the car downshifts before the final stop.
When in S (Sport) mode, I do not get that THUMP as consistently, though it still feels like something may not be right.
The diff has been serviced (92k by Mercedes Indie, and car was a CPO before me so hopefully before that, too), as has the trans and filter.
What should I be looking for when I put the car on jack stands? I also do not get the thump when braking (from 30mph to 0) when the car is in neutral. It seems to be either the transmission, or something in the differential. Need knowledge! Will test/pics/whatever is necessary, otherwise I may have to pay the dealer to diagnose.
Thank you MBworld!
[edit]
'Yes, ALL fluids and filters were done around 96k (and probably prior). The brake fluid (for example) looks brand new (reservoir clear, etc). I was happy with this part of the service they performed.'
When doing moderate (60%+ braking, and in W (winter) mode, I get a single THUMP from (what feels like) the rear differential as the car downshifts before the final stop.
When in S (Sport) mode, I do not get that THUMP as consistently, though it still feels like something may not be right.
The diff has been serviced (92k by Mercedes Indie, and car was a CPO before me so hopefully before that, too), as has the trans and filter.
What should I be looking for when I put the car on jack stands? I also do not get the thump when braking (from 30mph to 0) when the car is in neutral. It seems to be either the transmission, or something in the differential. Need knowledge! Will test/pics/whatever is necessary, otherwise I may have to pay the dealer to diagnose.
Thank you MBworld!
[edit]
'Yes, ALL fluids and filters were done around 96k (and probably prior). The brake fluid (for example) looks brand new (reservoir clear, etc). I was happy with this part of the service they performed.'
Last edited by phoenix_iii; 04-02-2010 at 09:15 AM.
#2
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First check your fluid level, this transmission is critical of fluid level. It's odd that you get the symptom in W (1st gear bypassed) and not S mode. Look for a leaking trans plug wicking fluid up to the electronics, check u joints and flex discs, and look at trans mount.
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I do not have the service manual. Are there any threads where people have posted pics of the...
1) U-Joints
2) Flex Discs
3) Trans mount (if not obvious).
Low fluid/pre-purchase inspection tutorial said to do a 'really slow' 1st to 2nd shift (in D(rive), just let the car go, nice and slow), and the car shifts very smoothly.
I almost wonder if it's Suspension (or a mount), because it's only when done at 60%+ in terms of hardness, typically. I hate 'forcing it to happen' because I worry I will make something minor (worn trans mount, let's say) into something major (broken mount, etc)!
I will take pics this weekend.
1) U-Joints
2) Flex Discs
3) Trans mount (if not obvious).
Low fluid/pre-purchase inspection tutorial said to do a 'really slow' 1st to 2nd shift (in D(rive), just let the car go, nice and slow), and the car shifts very smoothly.
I almost wonder if it's Suspension (or a mount), because it's only when done at 60%+ in terms of hardness, typically. I hate 'forcing it to happen' because I worry I will make something minor (worn trans mount, let's say) into something major (broken mount, etc)!
I will take pics this weekend.
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2007 C280 4matic Avantgarde
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2007 ML350
ontmiss. Nice! That covers the C230 as well I take it? Downloading now!
Edit. Looks like it is the Owner's Manual. I have one of those, but the PDF is GREAT (easier to search), so still a GREAT link. thank you.
=)
Edit. Looks like it is the Owner's Manual. I have one of those, but the PDF is GREAT (easier to search), so still a GREAT link. thank you.
=)
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2007 C230SS; 2014 ML350 BT
When you say "fully serviced", does that mean the transmission has been serviced? If you have never had a transmission service, it is time.
Follow mleskovar's advise.
Follow mleskovar's advise.
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Yes, ALL fluids and filters were done around 96k (and probably prior). The brake fluid (for example) looks brand new (reservoir clear, etc). I was happy with this part of the service they performed.
I DID ask for a sample of ATF to send off, but they failed/forgot to do this... but the slow take off from 1st to 2nd is very smooth, and I do check this periodically (warning sign of contaminated ATF is jerk going from 1st to 2nd on slow acceleration). Updating original post.
I DID ask for a sample of ATF to send off, but they failed/forgot to do this... but the slow take off from 1st to 2nd is very smooth, and I do check this periodically (warning sign of contaminated ATF is jerk going from 1st to 2nd on slow acceleration). Updating original post.
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2001 Mercedes Benz C240
i have the same problem and with my 2001 C240 it hesitates to shift from 2nd to 3rd gear also. i went to dealer and they told me i need a new flex disc and trans mounts. how much do you think that repair would roughly cost?
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2007 C230SS; 2014 ML350 BT
Yes, ALL fluids and filters were done around 96k (and probably prior). The brake fluid (for example) looks brand new (reservoir clear, etc). I was happy with this part of the service they performed.
I DID ask for a sample of ATF to send off, but they failed/forgot to do this... but the slow take off from 1st to 2nd is very smooth, and I do check this periodically (warning sign of contaminated ATF is jerk going from 1st to 2nd on slow acceleration). Updating original post.
I DID ask for a sample of ATF to send off, but they failed/forgot to do this... but the slow take off from 1st to 2nd is very smooth, and I do check this periodically (warning sign of contaminated ATF is jerk going from 1st to 2nd on slow acceleration). Updating original post.
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2007 ML350
I have not changed the Transmission Mount. I will search to see if I can find a DIY.
I do not know if the problem started before/after the service, I brought the car in immediately as I got it from a private sale and wanted to catch it up on service.
mbdragon55 - My problem is different, please start another thread/search/don't confuse my helpers!
Thank you everyone so far for questions/input!
I do not know if the problem started before/after the service, I brought the car in immediately as I got it from a private sale and wanted to catch it up on service.
mbdragon55 - My problem is different, please start another thread/search/don't confuse my helpers!
Thank you everyone so far for questions/input!
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Anyone have a link to the DIY (did not find), or the PDF on how to do it, and the part #? I bet the car needs it, and I would like to do this.
This issue still worries me... a lot. Car just turned 101k miles.
This issue still worries me... a lot. Car just turned 101k miles.
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2006 C230, 2006 BMW M3, bye bye C55:(
Im just gonna put this out there, my Service advisor is resetting the cars TCU to adjust this problem as we speak. Maybe give it a shot?
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cfw, Is there a fee for this? I would imagine it should be a courtesy service... =) I'd like to say that other dealers/SA's perform this for free.
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https://mbworld.org/forums/c-class-w...-question.html
If it needs to be reflashed/programmed it will cost you.
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read the whole thread (very interesting). Only post #4 (I think) mentioned how to do the reset
'you mean the throttle adaptation reset trick? the one where you hold the throttle down with the engine off, key in on position. i've tried that'
But it was not very descript. Anyone know the step by step procedure? That thread sounds like my problem, explained by Glynn well as drivetrain lash, probably exacerbated by flex disk, ujoint, etc etc...
'you mean the throttle adaptation reset trick? the one where you hold the throttle down with the engine off, key in on position. i've tried that'
But it was not very descript. Anyone know the step by step procedure? That thread sounds like my problem, explained by Glynn well as drivetrain lash, probably exacerbated by flex disk, ujoint, etc etc...
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2007 C230SS; 2014 ML350 BT
Still getting used to WIS, so I am bot quite sure about the notes on self locking nuts and bolts. It in not clear if none, some, or all, of the bolts are self locking and should be replaced when servicing. Maybe one of our gurus here can chime in about it.
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2006 C230, 2006 BMW M3, bye bye C55:(
Theres a 100$ fee that is basically reseting the control moule from the gear selector (egs) to the tcu and the esp(electronic shift plate). The car runs and drives 10x better now Shifts are much faster and smoother