I recently test drove an 84 300d w/AT and 349K miles on it. The car looked to be well cared for with an excellent rust free body, very nice interior and good running engine. The car drove nicely except for the 1-2 shift which was quite harsh, otherwise the trans. seemed to work nicely.
High miles, but because the car looks like the previous owner was meticulous, I'm considering buying it at about $2k. Does anyone out there have any thoughts on what could be wrong with the tranny, if anything ?

__________________
Diesel-guy

Welcome to the forum!

You'll find this "problem" just one of the slight differences if you're just switching to diesels from gas vehicles. I've found this characteristic sometimes smoothes out by itself once the engine/tranny fluid reaches operating temp.

Good luck!

I've corrected the problem a couple times by doing a Mobil I synthetic ATF and filter change. Remember to drain the converter. You can find the Mobil I ATF at Auto Zone.

As long as the shifts were okay and no major flairing occured then likely the harsh shift can be adjusted out and the switch to synthetic atf will also improve this as stated above. Sounds like a nice car at a decent price. Check it over really well and good luck. RT

__________________
When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

There are some up grades for those tranmissions that have the hard shift from 1 to 2.. the factory and several aftermarket company put them out.. However I have never came across one that has been redone.. and the shift does get some softer once the trans oil is warm.. Its really normal for most of the 84 and 85 diesel cars.. There are several things you can do to try to solve it but most of us just drive it and forget it..

Ken

Hi, thanks to all for the good tips on the tranny situation. I feel much better about the prospect of purchasing this car now.
The various tips have led me to believe that this car has a weak vac. pump or a vac. leak as the locks are slow to act and the engine doesn't shut off immediately after turning the key.(approx. 1 second) Does this make sense ?
I'm new to this forum, but it seems like there are some very helpful and knowledgeable people here and I look forward to visiting frequently in the future.

__________________
Diesel-guy

My 84 300D Turbo has a little bit of a harsh shift from 1-2 and I understand it can be perfectly normal, although a "harsh shift" is a subjective thing.

A nice rust free example for 2k seems like a good buy.

Unless you have been around many of these cars I would suggest letting a competent mechanic take a look at it.

Good Luck.

__________________
RT


1984 300D---Sold
1995 E420 - 106K - Brilliant Silver Metallic/Orion Gray --- Sold
1984 300SD - 151K Manganese Brown Metallic/Mostly Black --- Sold
1982 240D - 79K - Manila Beige/Palomino---Sold

Check under the car on the drive shaft. There should be 2 rubber couplings, one front and back. Check for any movement, if any this was the cause of my rough shifting, minor repair. Also did the transmission fluid change along with filter as mentioned above. Car shifts fine.

It's pretty normal for the locks to "ooze" up and down with vacuum system...shouldn't take more than a second or two, but not the "instant" action of electric locks. Also "normal" for a diesel to keep firing for a second after being shut down...part of the way diesel engines work that takes getting used to, and it isn't "run-on".

One nice things about these durable cars is that a LOT of knowledge about their problems and how to cure them has accumulated over the last 20 years, and much of it is archieved right here on this site. Good luck!

Brad,

I would always have a compression test done to verify the internals of the engine are in good shape. If the cylinders and pistons are ok, the rest is pretty much within the reach of a good, or at least interested in learning, home mechanic.

Depending on how long the engine takes to shut off, and how slowly the locks move, you may have a vacuum leak. I doubt the pump is responsible due to a weakness in the pump though. More likely a fitting or mechanism that is leaking. Slow locks and failure to shut down the engine with the key are vacuum leak type failures.

Good luck, and enjoy the car. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

I would not worry about the locks being slow.. If you can lock it and then go back later and unlock it and they all move and then relock it with the engine off odds are its fine....

As far as a compression check.. Good idea but if not practical at the time.. be sure the engine is cold.. That some one did not start it and warm it before you got there.. Glow it normal time and hit it then.. If it starts right up odds are it has good compression.. If you have to glow it several times odds are it does not.. Then look for blue smoke from it.. Do not worry about a gray or blackish smoke.. Thats diesel.. But the common old blue smoke you get when you go off throttle in any car.. That will give you some idea as far as rings and oil use... For that price you are just buying the miles left in the car whitch can be a lot..


Ken