82 300SD tranny question
 

I have noticed that when the engine is cold in particular, as I get up to about 30 mph, while accelarating, it seems like the transmission isn't sure what gear to be in, and the car sortof surges, and lags until I get moving a little faster. Is this a normal thing with everything cold. It seems to go away by the time the temp guage gets to 80 C.

When cold, you'll definitely notice that the 1-2 shift is delayed a bit and it requires you to press down a bit more and get the speed higher in order for it to shift. This is certainly due to the temperature of the fluid. It's much more pronounced in the winter months. I don't notice it as much on the 2-3 or 3-4.

I am curious what the shift points are set at, although clearly that is pretty variable, depending on temp and engine RPM. My last car wouldn't shift into 4th no matter how fast you were going until it was warmed up.

Ok, so this thing has been getting worse, and I called a guy that works on Mercedes pretty much exclusively. As soon as I told him, what it was doing his first thought was to replace the tranny with a rebuilt one. I asked him if it wouldn't make sense to try a new filter, and fluid, and see what happens. Is there anything else I should have him look at on this? I made an appointment for Thursday morning, so any help would be great.

My advice is to find another shop. This guy is simply out to take your money. He'll never find the problem because he couldn't care less.

Synthetic fluid (Mobil 1 Synthetic ATF) practically eliminates any lag in shifting or shift quality when the tranny is cold...it made a world of difference for me, I'd recommend it to anyone! :D Even on normal dexron fluid though, if its over 45-50 degrees outside it should shift fine even when its still "cold"...mine only got sluggish below freezing, which it is for a significant part of the year around here:rolleyes: , so synthetic worked wonders....

I have no idea what is in there now. What I have noticed is that in the time I have had it, the shifting has gotten noticeably worse. I don't know what the actual situation is. It didn't appear to leak where it was parked before, and everything looked clean underneath when I looked. It is however leaving small spots, which I can't give you any more detail about, because my driveway has brown gravel in it. When I suggested replacing the fluid, filter and gasket the guy said ok, and then said that if there was metal shavings in the pan that I would need a new transmission. Is this true? How long does the transmission typically last? He also mentioned that it would NOT be a mercedes transmission, but it would be the same type, just not made by them. (Is this a bad thing? Should I just not show up for my appointment and do the filter and fluid and gasket myself?) Considering that I have only had the car 2 weeks I'm starting to wonder if the guy I bought it from knew the problem, and did something to get it through till it was purchased.

..........see post #5.

Ok, so while I don't disagree with you, Brian, I'm trying to cover all the bases I can here. I have heard that the B2 piston can go bad on these cars. What are the symptoms of this?
The reason I'm even talking to this guy is that he was recommended as a good person, by a mechanic that I trust. I'm not having a lot of luck finding anyone to work on this, and my time, skills and tools are quite limited, although the filter and fluid would be within bounds if I had the tools, and a place to do it.

Also my gf says I should at least go to this guy one time, because he is all we know and its her uncle's recomendation, and he wouldn't recomend somebody he doesn't trust. Yes, that is a stupid reson to use somebody, but in this case...

Well, you can listen to your girlfriend or you can listen to me.

I'm telling you to avoid that AH at all costs because he will not find your problem and you will spend hard earned money to replace the transmission once he opens it up. And, he'll probably charge you $2500. to replace that unit when you can find one for half that amount (plus installation).

So, go on the forum and search the recommended shops in Missouri........there is a separate thread just for that state..........and find someone who is reputable and won't just take your money.

I have looked, and the pickin's are kinda slim here, however first thing in the AM I'm calling a different shop. One of the only non-dealer shops that was recommended.
BTW, I'm not trying to be an idiot.

I know full well that you're not.

It's the nature of the situation. Person seems like they have no other options.........mechanic comes recommended by uncle.........but uncle doesn't realize that mechanic doesn't know squat about transmissions..........so person takes vehicle to mechanic and trusts mechanic.........mechanic tells person that he needs a new transmission............

Do you know how many times this has happend to other folks........???

That's why I'm being a bit strong willed here.........I'm trying my best to prevent it from happening to you.

If you had to drive that vehicle 100 miles to a mechanic who knows the transmission on that vehicle........it would be worth your effort.

Tell your gf, you have heard and considered her recommendation but you have decided otherwise. (Stand up straight and tall when you say it.;) )

I have been down this road with other cars and ditto Brians recommendations. In fact, from his comments of "same type not Mercedes" I would walk in the opposite direction at a minimum of a fast pace. This guy is after nothing but $$$'s. :greedy: (We are not talking about his quality of work.)

Do the fluid (torque convertor also) and filter change along with possibly some TransX. Then you definitely have somewhere to start with a baseline. Then come back here with your results.

How does the car idle?
 

belive it or not, shift uncertainty could easilly be attributed to a weak injector... hear me out.
if the injector is not working to spec, your other cyllinders will be working to take up the load. so you will put your foot into the pedal a bit more, and the tranny shifts based on where your foot is.
it certainly will not hurt to change gaskets, fluid and filters, and I really like synthetic tranny fluid. but getting the engine running solid may solve your particular problem. the surging kinda makes me think engine problems, possibly timing chain, or valves.
I am not a Diesel Mechanic, but my 82 SD runns like a sewing machine.
John

I can see how that could work, but wouldn't you hear that when the engine was sitting at idle? Everything seems to be pretty good, as far as how the engine runs, its nice and smooth.