I could really use some advice for a friend about a drive train issue - Page 3 - PeachParts Mercedes-Benz Forum

spree17 · #31 06-03-2010, 06:17 PM

Quote:

Originally Posted by slk230red

Yes, that's about it. One thing I like to do is put witness marks on the shaft/connectors so that the drive shaft goes back on the the same position.

I read about that and I would do that. I think I could do this job if I had a lift for sure but I'm concerned about trying to do it with little clearance on jackstands or light. I'm also concerned because I'm not sure of the problem yet

spree17 · #32 06-03-2010, 06:20 PM

Quote:

Originally Posted by slk230red

Remove filler plug at differential, stick your finger in the hole, if low, add fluid, screw filler plug back in.

Sounds complicated.

In all seriousness is it just if the fluid is below the whole it is low? I havent used my finger as a dipstick before.

Last dumb question. Which side is the filler plug facing?

slk230red · #33 06-03-2010, 06:22 PM

Before doing anything else, have your friend take off in the car and watch the rear wheels real close. I had my wife take off in hers and I could see a lot of movement in the right rear wheel when the sub-frame mount went bad. It made a hell of clunking noise when taking off, then smoothed out.

spree17 · #34 06-03-2010, 06:25 PM

Quote:

Originally Posted by slk230red

Before doing anything else, have your friend take off in the car and watch the rear wheels real close. I had my wife take off in hers and I could see a lot of movement in the right rear wheel when the sub-frame mount went bad. It made a hell of clunking noise when taking off, then smoothed out.

That is really interesting because that is how his is.

From a stop you have hesitation, slight grind, clunk then smooth going

I dont even know where the sub frame mount is. I will look that up.

slk230red · #35 06-03-2010, 06:25 PM

Quote:

Originally Posted by spree17

Sounds complicated.

In all seriousness is it just if the fluid is below the whole it is low? I havent used my finger as a dipstick before.

Last dumb question. Which side is the filler plug facing?

It's on the passenger side of the differential. I just changed the fluid recently on the 190 and the SLK230.

Maybe after this you will want to change your user name to "Dipstick"

slk230red · #36 06-03-2010, 06:30 PM

Quote:

Originally Posted by spree17

That is really interesting because that is how his is.

From a stop you have hesitation, slight grind, clunk then smooth going

I dont even know where the sub frame mount is. I will look that up.

Well, you need to isolate the problem. Does the above start happening before the rear wheels start turning?

After I saw my wife's 190 right rear wheel moving around at take off, I jacked up the right rear, removed the wheel, then used a 2 x 4 to lift up on the suspension. I could see movement/play in the sub-frame mount. It was obvious that the rubber bushing was toast.
It was hard to replace but I got it done in one afternoon.

spree17 · #37 06-03-2010, 06:35 PM

Quote:

Originally Posted by slk230red

It's on the passenger side of the differential. I just changed the fluid recently on the 190 and the SLK230.

Maybe after this you will want to change your user name to "Dipstick"

Thanks. Only my friends call me that.

spree17 · #38 06-03-2010, 06:36 PM

Quote:

Originally Posted by slk230red

Well, you need to isolate the problem. Does the above start happening before the rear wheels start turning?

After I saw my wife's 190 right rear wheel moving around at take off, I jacked up the right rear, removed the wheel, then used a 2 x 4 to lift up on the suspension. I could see movement/play in the sub-frame mount. It was obvious that the rubber bushing was toast.
It was hard to replace but I got it done in one afternoon.

I think all that does happen before the wheels start moving. I will double check that and get back to you.

spree17 · #39 06-03-2010, 10:52 PM

Quote:

Originally Posted by tinypanzer

I'm still not convinced the problem is not in the trans. You say the problem happens every time you start from a dead stop. Well, let's use our imaginations for a second..... Any slop in the drive train will get taken up when you shift from park or neutral into drive, right? The torque from the trans is supposed to always be present on the drive train when the car is in gear. This is why the car starts to move by itself when you take your foot off the brake. So, that slop goes away the very first time you go into gear, right? Okay, so how then does it re-appear at every stoplight unless the driver is shifting to neutral?

The only way this could be happening is if the trans is not applying torque to the drive train at all times, and that points to trans problems.

If it is a tranny problem I think he would have to sell the car because he couldnt afford to put a new tranny in it.

spree17 · #40 06-03-2010, 11:23 PM

OK guys please bear with me because we seriously need and appreciate your help with this situation. We think we are getting closer to narrowing the symptoms and the problem down. Here are some updates:

1. We tried shifting directly in to 2nd and 3rd gear instead of drive to see if that made a difference. Trying to figure if it was a 1st gear problem since it drives fine once moving. It didnt make any difference.

2. I did notice it not only when starting off but now when hitting the brakes and coming to a stop we feel it also. It seems to be coming from the shaft or axle area more than from the tranny but that is just my hunch for now.

3. When we step on the gas hard we feel it but if we step on the gas really lightly to start off it doesnt happen at all.

4. I dont ever feel it in reverse but since I'm usually going very slow in reverse.

5. Do these descriptions of the problem help anyone in trying to figure it out?

6. Does those bolts look like they are lined up correctly on the front disc pictures or are those curved areas supposed to be in the raised curve area of the plastic/rubber? I posted the picture previously in this thread

spree17 · #41 06-07-2010, 11:35 AM

I have a few updates but before I get to them I really wanted to thank everyone in this thread for their help.

1. My buddy was so frustrated and worried about all the things this issue possibly could be that he just wanted out of the car so I bought it from him this weekend. I now own 2 190e's

2. I finally got under the car with the correct jack, jacks tands and a light. Visually both flex discs looked fine. I was stumped and concerned what could be the problem. I started playing with the drive shaft and noticed some slack but not a large amount. When I went to the rear of the car I didnt notice any slack but I did notice slack from the front. So I went back to the front disc. While visually it looked OK I noticed when I turned the drive shaft 2 of the (15mm socket) flex disc bolts were moving. I hoped I could just tighten them and the problem would go away but the problem remained although it seemed lessened. The bolts still seemed to move even when very tight so my guess is that the flex disc is bad. I'm going to hope that is the only thing causing this problem. It was changed around 61,000 miles ago.

3. When in the back looking at the differential there are 2 round wheels on each side. I dont know what they are called. 1 side seemed totally straight. The other side did not seem as straight. Do you know what the wheels are called? Would 1 not being 100% straight be a major issue?

4. Would I be better off ordering a Lemforder or a Febi Bilstein front disc?

Thanks once again. I guess I will order the front flex disc, attempt to change it out myself and hope that was the problem. It probably is. Would seem a bit coincidental for that not to be an issue since it is 2 of the 3 bolts that are moving.

ps2cho · #42 06-07-2010, 01:05 PM

Quote:

Originally Posted by ps2cho

Definitely needs attention as there are gaps which allows for slack upon movement (hence why you only notice it while moving)

The first part of the flex disk's wear comes at the holes as they widen and can cause the clunking you are noticing. The washers actually mask the holes to some extent, but under a closer inspection (and turning like you did), you'll notice quite some slack.

Now get on and swap'er out!

I would go with whatever is cheaper. Both are quality, but these flex disks wear either way. Unless someone has used both and can comment of course! (which would be at least 150k+ miles worth of experience on the same car under roughly the same driving conditions)

pop & blow · #43 06-07-2010, 01:40 PM

flex disc not mounted correct, should be aligned in proper recess.

spree17 · #44 06-07-2010, 01:49 PM

ps2cho,
Thanks for the explanation. That makes me feel more confident that the disc is the problem. I ordered a new Bilstein disc 15 minutes ago.

Pop & Blow Thanks for the tip. Sounds like that could indeed be the problem.

spree17 · #45 06-10-2010, 12:41 PM

OK the good news is I got the part.

Bad news is the tranny cross-member bolts seem to have been put on by the incredible hulk. I'm having big trouble getting them off. I dont have an impact wrench. I used to use a long torque wrench for leverage in the past and that worked well but that wrench got up and walked away one day. Any advice on how to get the tight bolts loose? Should I go buy another torque wrench or some sort of breaker bar?