neurodave

Symptoms:

At any speed under 10MPH (+/-) in stop and go or slow traffic the car seems to jerk itself around. I want to say it feels like it "let's go" of the transmission and when you press the gas again it jerks itself back into place and moves. Driving in a scenario where you're constantly stopping and going is frustrating. I have to stop, let traffic move up, speed up and either let it shift into 2nd which alleviates the issue a bit, or come to a complete stop, then go.

Also, 80% of the time when coming to a stop at a light or intersection, once it's under, say, 7MPH you can feel this "click" and slight jerk. Interestingly, it doesn't happen if I brake a bit more firmly, especially from high speeds. Might be suspension related? Not sure.

So now I don't know where to go. Fluid was done over the summer, no metal pieces. Transmission shop that it's at says transmission is fine, the car may need a tune up. Would the engine have a minimal issue affect its shifting? The car just had plugs and wires done last year, but I do notice a slight RPM dance when idling in D.

Any advice would be appreciated!

neurodave

....anybody? Lol.

jkowtko

If the tranny is really okay, then there can only be so many other things that could have slack in them. I suggest also checking:

* front motor mounts
* rear tranny mount
* flex disks
* front suspension control arms
* top strut mounts

* And a less likely culprit would be the steering rack bushings.

neurodave

Update: $900 to MB later to replace both flex discs, bushings and trans mount and it's shifting a bit better. The big change should come when they do my motor mounts. Parts are on order, about $690 to do them all at MB. It still has the odd little jerk when slowing down below ~10MPH, but we'll see what happens when they replace the motor mounts. Mine were collapsed, flex discs cracking and trans mount weak.

jkowtko

fingers crossed ...

neurodave

Thank you, same here! Already shifting better, much firmer. Still a bit sloppy and clunky, but I think the motor mounts will finish it off.

Glyn M Ruck

Good call jk!

neurodave

Motor mounts went in today, and low and behold, my trans connector bushing thing-a-ma-bob was leaking, so they replaced that too. I have only had the 20-30 minute drive home to test it out, but it does feel better. More responsive, so quiet and calm at a red light, and the shifts seem to slide right in. Tomorrow it will get the full test to check for symptoms, but so far so good!

ogaiyingh

Mine were collapsed, flex discs cracking and trans mount weak.

neurodave

Same here, motor mounts collapsed, flex discs gone, trans mount gone.

neurodave

Update: Finally got some decent driving in and low and behold........same issues. I'm starting to believe it may be my subframe bushings or something in the back. Essentially, when I'm coming to a stop, it does this "click" and then a jerk you can feel in the car. The vehicle itself does NOT jerk forward or backward, but it creates enough movement where you feel it in the cabin. It also seems to have issues with the way it managers power at low gears. If I'm doing under, say, 10MPH, and I let go of the gas, it will boggle down and then when I press the gas again, it comes back to life and jerks itself back.

The only thing the repairs I did fixed, was tighten up the shifting, and even that is still buggy.

I'm not sure where else to look for a solution.

jlr82

This may be a long shot, but I had *very* similar problem as you are describing. I live in St. Louis city and therefore do a ton of stop-go driving. In St. Louis we like the call these "rolling stops" where you don't quite come to a complete stop before continuing through the intersection.

Like you, during these types of driving I would experience what I considered a delay with what I considered to be followed by a thrust of power to the drive train. It never felt right and while I experienced/felt it all the time it was hard to get a tech to recognize the issue when I would (attempt) to recreate it with a tech in the car.

I took my car in for new struts over this past weekend and also complained (again) that I'm experiencing a new issue with the transmission where the 2-3 upshift had a weird delay where it felt like it was going to shift but didn't, immediately followed by a normal shift to third. When I got the car back they told me that the tech did experience "harsh shifting". They performed an upgrade of the Transmission Control Unit's software and did some manual adaptations. After picking up the car the issue is gone and I can't replicate it anymore. I also don't have the lag/delay whenever I slow down in traffic to make a turn and then get back on the accelerator half way through the turn (this used to make a thud/jerking movement too). My dealer didn't charge me anything for looking at the transmission and doing the TCU update, but I was also paying them over $1k for the new struts.

neurodave

Thanks for the advice! I have heard of the before, but the issue with me is that if I recall the pre-02'ish (03?) models can't have their TCU reflashed, someone correct me if I'm wrong. I am still taking it back and having them check everything again, for free, because I paid close to $2000 total to fix the issue, and the issue wasn't fixed.

RCPDesigns

I see that you have said that the transmission is OK, but the issues your are describing (or at least they way I'm understanding it) sound a lot like the conductor plate/valve body/etc. This video is part of a 6 part series... find the first one (or so) and see what you think. Maybe you already had this work done but if not... the video might be applicable.

neurodave

I saw all the videos in this series, they are excellent! I considered this being the issue, and it was on the top of my list to be honest, but the MB dealership stated that they were sure that the mounts for the motor and trans were the culprit and while I did mention the conductor plate, they said they got no codes from the ECU or TCU. Either way, cars going back next Tuesday and they're going to figure it out.

insame1

+ one on the conductor plate. Also if you you are replacing that have them replace the TCC lockup solenoid. Most of the time they will try to change the valve body also but i have never had to replace one of those.

neurodave

All I see on all these posts are dollar signs left and right.

Considering the $2K I just spent to supposedly fix the issue, anyone have any advice on how to approach the dealership with this next week? They told me those repairs I did would fix it, but it didn't. And I am sure that with the conductor plate and lockup solenoid, I am going to be toying with another $2K price tag.

RCPDesigns

I feel you pain as I have 4 cars to maintain. Within the last year I decided that I would be doing the work myself. It has been a wonderful decision for me so far. I go to the dealer/indy now to get a quote and then find a DIY in the forum and/or a video on YouTube and get to work. I've saved a LOT of money. One thing I've noticed is that the dealer/indy doesn't really 'lie' on the quote. The parts do 'list' for the amount they say they do. The numbers they quote for labor come from MB as a standard (I guess). That said... if you shop around (rm european, ECS tuning, mbwholesaleparts etc) you'll find you can get genuine MB parts for a good bit less. Used parts from eBay might work as well depending on what you need. You'll also find that you can get the work done in less time MB says it will take. The biggest savings is the labor... my indy charges $165/hour and I'm sure MB charges that or more.
So.. if you have the time, place and capability then DIY. If not, ask around and try to find a good Indy. If you don't feel comfortable with that... then the dealer is your only option. In that case you need to build a relationship. Let them know you understand your car and value their capability. Work with them and hopefully they will work with you.

jkowtko

All of the above were probably needed for your car, so don't sweat the fact that you paid money and still haven't solved the core problem yet. You've just done your car a big service by replacing those parts ... and you will benefit from it over the next several years.

That being said, you paid $2k for a number of services for which the parts cost is probably $400-500 total. So figure labor charge and MB parts markup make up the remaining $1500. Not surprising to me.

Regarding transmission valve body work, yes the dealership may try to charge you another arm and a leg to replace the conductor plate. The book times on this is probably way more than the actual time it will take:
* drain tranny fluid through plug, 1 minute
* 6 small bolts to remove tranny pan. Gasket and filter come right off. 2 minutes
* 10-11 small bolts to remove the valve body. Valve body lifts right down. 5 minutes
* 2 solenoid covers pop off, three screws holding down solenoid brackets, solenoids pull out, conductor plate pulls out. 5 minutes.

So if you know what you are doing and have the right tools and a lift, you can probably have this entire thing done with conductor plate and a few solenoids swapped out in under an hour. There will be extra time that the car just sits unattended to drain fluid, and to warm up the fluid at the end when you are checking fluid level.

Now that you have an idea of what is actually involved in doing this ... I suggest that you ask the dealership to swap out the conductor plate and maybe a solenoid or two for reduced or no labor charge. They will probably quote you for $1000+ for labor ... I suggest if you can get them down into the $250 range it will be well worth it. What will take them one hour to do would take you 4-5 hours.

As for parts cost, a new MB conductor plate with MB filter, gasket and Electrical connector seems to go for ~$150 online, and solenoids ~$60. Expect MB to charge you at least a 50% premium over those prices.

-- John

neurodave

I figure they will hit me with somewhere around $1300 for the entire thing IF that is the culprit. Either way, I plan to ask for SOME sort of discount if that is the case. I brought the car in to fix those specific issues, not the others. If I could get them down even $200 I'd be happy.

Thanks for the help everyone! I will let everyone know what happens on Tuesday.

jkowtko

Also keep in mind ... sticky valves within the valve body could also be a source of the problem. I don't know all of the details, but with steel valves and aluminum valve body I understand the valve holes can wear over time resulting in slow or delayed movement, or pressure loss/leakage. If that is the case then I would assume a valve body rebuild is in order. There are places that do valve body rebuilds. I called one in my area -- http://www.pdqparts.com/ -- who uses Sonnax parts and charges $600 for the rebuild. I didn't ask them if new conductor plate and solenoids are included or not ... if they are, then that's starting to sound like a really good deal if you're going to replace your conductor plate and maybe a solenoid or two anyway.

neurodave

Update: Just left MB in Morristown. I took the car for a test drive with one of the mechanics, we spoke a bit about the Valeo radiators, glycol contamination, shift adaptations, and a few other things. In the end, the mechanic said that I had some driveshaft play. They brought me in and showed me how they could spin the driveshaft a little left and right with ease. The mechanic ran me through their STAR system and showed me all the tests came out OK. He did a quick test, no codes, no errors, nothing. Only thing he pointed out was the shifts between 1-2 had a high level or pressure or something? (told me it was at 740, whatever that means) but regardless, while high, he said it wasn't out of spec.

So with that driveshaft issue being the culprit, I am at a standstill. The repairs are WAY too much, to the point that they didn't even want to give me an estimate on it because it just wouldn't make sense to do it.

So I'm not sure where to go from here. The service advisors suggestions was to drive it until it dies. I'd love to keep the car for longer, but I think I may have hit a dead end.

Thoughts?

insame1

Ditch the dealer and find a indy.

neurodave

I wish it were that easy but there are so many shops here in the NY area, that I'd have to go on a spree to find a competent one. I've already had a fair share of incompetent ones, I figured the dealership could be my last (expensive) resort.

One idea I had in mind was the bearing in the middle that holds the driveshaft. When he showed me the driveshaft the car was in N and it could turn roughly 1/4" or so in either direction.

I want to believe that theory, because it makes sense, but then I don't....

Critter

The bearing just supports the drive shaft, if you have that much play back and forth then rear diff is where the action is.