87 300E No Upshift

I am the second owner of an 87 300E with 125k miles. The car’s transmission worked very well until one day it refused to upshift. I spoke to two Mercedes mechanics in my area and both offered reasonable prices for a rebuild ($1650, $1700) but were not willing to consider the possibility of making a partial repair. I understand their position but would like to get advise on possible causes and partial repairs before electing for a full rebuild.

Here are some characteristics of the problem:
1. If the selector lever is placed on the lowest option (2) the car will start out in first gear but will not upshift until the selector is placed into the next highest position (3) – then it will shift into second gear normally but will not upshift beyond second gear.
2. If the selector lever is placed on D the car will start out in second gear and will not upshift even at 5,000 rpm.
3. Otherwise the transmissions behavior is normal.
4. Fluid level is correct and fluid condition appears to be good.
5. The transmission does not leak.
6. The transmission does not make any unusual noises.

Thanks,
Ethan

[stevebfl]

I will agree with the concept that one should completely go through a trans that old.

Of course that only means when there is reason to go internal. Your symptoms sound a lot like what happens when the kick down switch fails. Try unplugging the kickdown solenoid at the right rear of the trans. The wire just unplugs. Tie it out of the way and drive the car.

If I were dealing with it I would probably want to fully diagnose the problem before it came apart as a valve body might be my next idea what would be wrong. Don't want to find that out after redoing everything.

[mbdoc]

For that trans to up-shift the GOVERNOR must create pressure, then the valve body will the trans to shift to a higher gear.
Did someone with MB trans experience to drive it OR check the governor pressure?

MANY times the rear pump will seize & shear off the drive pin from the governor.
Time to repair that problem takes on 2-3 hrs & only $10-20 in parts.

Thank you stevebfl and M.B.Doc for the guidance. I really appreciate it.

I will first try disconnecting the kickdown solenoid and report back.

I have not had an experienced M.B. transmission tech inspect the car in person. But one of the techs I spoke to on the phone asked if the spedo was working because he said that if it was not working this was a good sign that the governor had failed. The spedo is working on my car.

Thanks again,
Ethan

The Problem is resolved! After unplugging the electrical connection at the kickdown switch the transmission works properly. Does this indicate that the switch is bad or am I jumping to conclusions?

Thanks again,
Ethan

[stevebfl]

The switch under the gas pedal is the likely problem. Its a cheap plastic switch, amazing it lasts as well as they do as cheap as they are and where they are located.

Thats great!

Thanks again for the expert advise.

Ethan

[pesuazo]

"I spoke to two Mercedes mechanics in my area and both offered reasonable prices for a rebuild ($1650, $1700) but were not willing to consider the possibility of making a partial repair."

And these 2 "Mercedes mechanics" wanted $1700 for a rebuild without even a diagnostic,which would have solved the problem, just like Steve solved it from God knows how many miles away (without even being present).

I wouldn't come back to those clowns.

Is this a great forum or what?

Steve, I owe you at least a six pack on my next visit to Florida.

[stevebfl]

I had nothing to lose, so it is a much easier call.

While I probably would offer diagnostics to a phone in inquiry, you shouldn't be too hard on a business for their phone diagnostics. Among other reasons, even at my shop chances are you won't talk to me unless you ask for me. I am with the cars. We have others who talk on the phone. In my case, someone inquiring about a trans problem will probably talk to my 25 year German partner, Walter, who is very competent, but the overhaul price is one of the distinct subject posibilities on an over 15 year old car.

[pesuazo]

I am humbled by your remarks, and thank you.
Your MB knowledge is astonishing, to say the least (I understand this has been acquired thru schooling and experiece)

Recent experiences with mechanics (not personally, but family members) have somewhat angered me.
This may be off topic, but I will tell you the story:
My brother in law bought a Mercury Grand Marquis, 1987 with only 55K miles $3500.00 (V8, 305 engine, power everything and all works) the idle is so smooth you only know the engine is running because the belts are moving. Inmaculate in and out (typical story of old couple where the husband dies). A year later (60k)the car stumbles as soon as it starts. He has it towed to a local mechanic, where he says it needs a transmission @ the tune of $1K, he sends it to another shop 1 mile away, same story.
My in law knows I love to play with cars, so he gives me a call (he only knows how to put gas in them, besides driving them). I almost hit the ceiling when I heard it.
I told him I could fix it much cheaper, if he pays my roundtrip airline ticket to NY for the weekend ($70 thru my sister who works for AA). Well, I get there, 1 hour diagnosing I decide it must be the fuel filter. I go to Autozone, buy the filter, put it in and EUREKA, car runs fine.
They wanted to rip him off. And those were "professional mechanics", I am a low-medium car DIY.

Electronics Engineer as a career.

Now he bought a 2004 4runner, and sold me the land-boat for $750.00

[87-300E_in_NC]

Do it yourself (DIY) can mean overcoming many issues in life, especially with the automotive industry....great story and way to go pesuazo! You saved your beloved family member much hard-earned money...anytime you can do that for anyone, I believe that the same possibilities will be headed back your way (law of Karma)

With confidence and patience, I believe that human beings can overcome most obsticle in life (if you make an attempt).

I have saved my family and many friends much hard earned money, and many times I have talked them through it over the phone as well, but mostly in person. I too have taken an airplane to go fix a car....to NY as well. I am a confident individual with many years as a mechanic, and if my 300E does not run well soon (the fuel distributor seal is leaking) I will have to replace the fuel dist!

Your story reminds me of when I was sitting in a transmission shop waiting to pick up a transmission for a friend. A lady and her 5 yr old son came in for a transmission service. She sat near me, and we talked small talk, until a "mechanic" came in the room and told the lady that her transmission will need to be rebuilt, and he was holding a syncronizer from a manual transmission in his hand with a shop rag...

I asked him where he got that part that he said he "found" in the pan.....well, the owner overheard everything, and came out of his office storming mad! The owner yelled at me, cussed me out and told me that I didn't know what I was talking about, and said that I was hurting his business. I told the woman what was going on, and she thanked me, and told them to put her car back together and she would be leaving. I stood up to the fat guy that owns the shop, didn;t blink at him, just started laughing because I knew the rip-off process was in progress. Most people wouldn't believe the many shops and mechanics that take advantage of people on a daily basis....but I am not saying that all mechanics and shops do this, all I am saying is before you spend any money, get a second or thirs opinion....to protect yourself, just like asking for another opinion before brain surgery !!

Good luck everyone

[stevebfl]

It's my guess that the percentage of dishonest people in the auto repair profession is no greater than the amount of dishonest people in society in general. I have met only one for sure in all my experience.

I have seen incompetence, mistakes, lack of training and tooling, poor management, and other reasons why people have gotten a poor repair experience.

Our shop does near 10,000 invoices a year. Just how many dissatisfied customers do you expect I should see if we do perfect work?

If you wish to find a profession with dishonest people in it, I would think one would look at a profession where the likelyhood of making money was high to begin with. I would look to medicine, law, financial advisors, insurance agents. Technicians didn't start off to be rich and often money is not one of their buttons.

[87-300E_in_NC]

Hi Steve,

As we all know, there are many dishonest people in the world, and my remarks were not meant to attack the auto industry, nor your shop, and you are right, money is not one of the buttons for me either, never has been. I'm doing alright....takin' what there's givin' cause I'm workin' for a livin'. There is nothing on this planet that will ever compensate me when I help others, and they can not afford to pay me, like helping people broke down on the highway, or helping someone get back on their feet because their car or truck died in their yard and they don't have transportation to and from work. The satisfaction of knowing that I helped someone with their problem is worth more than money could ever supply. I'm a people person...I can communicate with anyone, and I care about humanity and how people treat people.

My point in my last post is to get another opinion....just like consulting an attorney when you need to, or a doctor. I did not question you or your shop, nor your abilities....so please don't think you need to defend your position, because I'm there with you. The woman in my story above had an automatic transmission to be serviced....and the mechanic came out with a syncronizer from a manual transmission...just trying to point out that most people with little or no knowledge of mechanics can and do get ripped off. If you really want to see how corrupt people can be, just take a walk back in the history of politicians and slavery, and other "government" agencies.....let me stop now ....but you get my point. I am honored that professionals like you Steve are standing up for what you believe in, and treating people with respect and being honest about it. If you did not have honesty and integrity about yourself, it would show....even in these posts on this message board.

As I can relate an automobile to a human being, to me it's an outer representation of the owners' personality and therefore represents that person, and if it is not operating properly, then it needs to be fixed. AND, when the problem is fixed, it has a positive affect on the owner, since the automobile represents the owner. What mechanics and technicians do is a very important process of self-healing the owner. I personally know this to be true, and have noticed it for a long time now.

What technicians and mechanics do (whether they are aware of it or not) is part of a process called "Etheric Surgery"....and with the human being this process is a very important one when dealing with personal healing (which includes emotional, mental, physical and spiritual healing aspects of the human be-ing).