Flex Disc and Engine/Tranny Mounts

[benzonline]

My downshift is getting harsher I noticed and I probably need to do the engine/tranny mounts aswell. You sometimes can hear a knock sound if I get a hard enough downshift coming.

The shifting and downshift is also pretty sloppy in S mode...this is one thing I hate about this car is this garbage transmission. Its just never right.

Is the flex disc an expensive repair if I did all these together you guys think?

I got about 80k miles now.

[kevinzorz]

check to see if it is in fact the flex disc causing the knocking, I had the same problem, but it just turned out that it was my exhaust which was misaligned and knocking against the bottom of the car. a very simple fix

[OzC36]

Or maybe just check the automatic transmission fluid level?

[BALLLR]

yesterday I changed my transmission fluid at 174km, it wasnt too bad looking. It made the world of a difference in terms of the way the car shifts, especially when stopped.

[griplimited]

If you can lift your car up and get under there where both ends of the drive shaft are... you'll be able to see the flex disc. Mine were noticibly worn by looking at the mounting screw points and how misaligned they were.

IIRC, it was approximately under 300 USD per plate (two plates) and the mechanic charged me 150 for labor. Hope that helps.

[benzonline]

Thanks guys...

Im gonna have it looked at next week.

The transmission fluid was changed by MB 2 yrs ago @ 55k miles or so.

[Cru328prod]

lmao do you have any weight in the trunk?


downshift from Winter mode, and see if it does it!!!!!!!

lol this has happened to a few members....added weight does it too i think.......search

[benzonline]

Originally posted by Cru328prod
lmao do you have any weight in the trunk?


downshift from Winter mode, and see if it does it!!!!!!!

lol this has happened to a few members....added weight does it too i think.......search

The downshifting in winter mode is a bit more gentle occasionally it is harsh...its really intermittant on my car and depends on the speed im going when stopping.

[SLAMMED_C]

check the hardy disc.. if there is alot of play.. or any play for that matter.. CHANGE IT RIGHT AWAY. if that lets go your driveshaft will hit the tunnel of your car.. and set off the airbags.. the crash sensor is located just above that area! smart germans! but get it checked out.
as for engine mounts.. with your hood open so you can see the engine through the gap between the hood and cowling.. put the car in drive and hold your foot on the brake with the left foot.. rev the car up to see the engine torque and see how much play there is in the engine movement.. do the same in rev too. if there is excessive movement its a good idea to change them as well.

what year is your car? 1999 or 2000?
does your car just have a harsh downshift? any harsh upshift?
could be the tranny..

[Cru328prod]

if the motor mounts went, you would feel it when you drive. Like a massive vibration as soon as you put it in drive

[adelaros]

I have the same problem.

I have change the flex disk, mounts, transmission oil and the problem still persist, but only on downshift and not all the time.

It is a very intermittent problem.

[benzonline]

Originally posted by SLAMMED_C
check the hardy disc.. if there is alot of play.. or any play for that matter.. CHANGE IT RIGHT AWAY. if that lets go your driveshaft will hit the tunnel of your car.. and set off the airbags.. the crash sensor is located just above that area! smart germans! but get it checked out.
as for engine mounts.. with your hood open so you can see the engine through the gap between the hood and cowling.. put the car in drive and hold your foot on the brake with the left foot.. rev the car up to see the engine torque and see how much play there is in the engine movement.. do the same in rev too. if there is excessive movement its a good idea to change them as well.

what year is your car? 1999 or 2000?
does your car just have a harsh downshift? any harsh upshift?
could be the tranny..

My car is a 99....whats a hardy disc? I only heard of flex disc.

I'll tried the tecnique with the hood open but the engine movement seemed ok. Rocked back and forth a bit but nothing out of the ordinary.

In W mode when accelerating from a stop, since I got the car, when you give it gas and it starts to move...it starts moving but then there is a little "tug" 1 second later...almost like power is making its way down the line somwhere and when it completes it tugs and "off we go"....crap explanation sorry.

[Cru328prod]

lmao i think he means flex disk

Winter starts of at 2nd gear
Summer starts of at 1st gear

Now i know when downshifting Summer will drop 1st gear hard, and even harder depending on weight.

Now it that said, i'm asumming your man. down shifting?

If thats the case, its all the 202s do that

[OzC36]

My downshift is getting harsher I noticed and I probably need to do the engine/tranny mounts aswell.

I agree that the gearbox downshifts in the C Class can be harsh. But, if it is getting harsher, then it is logical that something is changing.

IMHO I would think that the ATF level should be checked to be precisely where it should be on the dipstick when the ATF temperature is at 80 deg C.

If the ATF level is correct, then you have a problem with the Auto Trans itself, or drive train.

That being the case, the next easiest thing is to visually inspect both the forward and aft flex discs on the drive (propeller) shaft.

It will not fix itself by us just talking about it, so get to work and report back on ATF level and flex disc integrity.

[benzonline]

**UPDATE**

I took her into the shop today...the flex discs were not cracked and the play was extremely slight...I looked at them aswell while it was up there and saw them both in good shape. They said its good and not needed to be changed yet.

Engine mounts are good aswell but I did have the original rear differential oil changed out with new OEM oil. That was overdue I was told.

[SLAMMED_C]

Originally posted by benzonline
**UPDATE**

I took her into the shop today...the flex discs were not cracked and the play was extremely slight...I looked at them aswell while it was up there and saw them both in good shape. They said its good and not needed to be changed yet.

Engine mounts are good aswell but I did have the original rear differential oil changed out with new OEM oil. That was overdue I was told.

The flex discs (hardy discs) should have NO play in them. they are under extreme forces and torque. if there is any play in them the flex discs should definitely be changed.

[benzonline]

I dont know I think it can go longer with 120,000kms on the clock with these flex discs? There are many 202s out there and many people I know that barely change the oil on them and they run like no tommorow so should I take the chance until a few months to change them?

[Cru328prod]

unless you see cracks, your fine! But it is somthing to think about replacing later down the line if you plan on keeping the car, i'm at 95,000 miles....i do like jack rabbit starts, spraying nos......and its still been fine......

but.....umm yeah there shouldnt be any play....at allllllllllll


your gears might be fawked!

i say drain the fluid, and look for metal chips!

[benzonline]

Nothing is wrong...the car drives beautifully. I will replace the flex disc in the front in a few months and I drive the car carefully anyways.

I doubt any of you guys shift at 2000-2500 rpm LOL

[Cru328prod]

is your car auto?

[benzonline]

it is

[Cru328prod]

Why are you shifting gears again?

[benzonline]

I meant I drive it slow and steady and the average rpm when the tranny shifts is at 2000-2500.:)

[SLAMMED_C]

Originally posted by benzonline
I dont know I think it can go longer with 120,000kms on the clock with these flex discs? There are many 202s out there and many people I know that barely change the oil on them and they run like no tommorow so should I take the chance until a few months to change them?
km's dont matter too much.. its over time the rubber deteriorates and then you get cracks and weak rubber.. wears easier.
just keep in mind that if the flex disc does happen to come apart for some reason.. the crash sensor is right above the tunnel where the driveshaft will be hitting.. all I can say it airbags cost alot to replace!!!
you should be fine for a couple months though.. just dont be leaving it for too long. better safe then sorry for a part like this.

[benzonline]

I say in September or sooner I'll do it then.

Ross have you seen many that broke apart?

[SLAMMED_C]

Originally posted by benzonline
I say in September or sooner I'll do it then.

Ross have you seen many that broke apart?
Ive never seen them myself.. but I have heard of a couple.

[OzC36]

This might help:

http://dieselgiant.com/Mercedes%20flex%20disc%20failure.htm

PS. Did you check your ATF to determine if the level is correct? Or are you just hoping ithe problem will go away? :)

[benzonline]

ATF is fine...the dealer did the tranny fluid change and this week there has been no harsh downshifts at all. :)

[OzC36]

Great to hear that. Thanks for the feedback!

[benzonline]

Front flex disc being changed tommorow! The downshifts are sometimes SLAMMING that I said "eitheir now or never"and I dont want to leave it parked for most of the winter knowing things need to be changed.