I have been told by more than one mechanic that changing the transmission fluid on my (77 300D) that has not been changed in long time is asking for trouble. Reason given is that the transmission might start slipping after the new change and basically disrupt all the internals. Would that be the case or does it all depend?? Shifts fine now and never had a problem but have not changed it in a couple years. Should I change it or am I asking for trouble?

^ I adhere.

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[/SIGPIC]~cirrusman

1983 Mercedes Benz 300SD - Wife calls him "Chitty Chitty Bang Bang"
[SIGPIC]




1983 Toyota Tercel (Tommy, The little Toyota that could)
1965 Ford F100 (Grandma Ford)
2005 Toyota Sienna (Elsa, Wife's ride)


Gone:
1988 Toyota Pickup
2004 Subaru Outback

1987 Cadillac Fleetwood Brougham
1986 Volvo 740 GL Station Wagon - Piece of junk.
1981 Volvo 242 DL 2 Door - Hated to see it go. R.I.P.
1987 Pontiac Fiero GT

X3 On Mr. Bible's sentiment.

I'm approaching my 30,000 mile mark and getting ready to do a change myself. The "sealed" for life mentality of domestic cars is a joke and something I don't believe in too. If the life of a car was the length of the lease then I can agree, but our cars last well beyond the average length of time most people drive cars here in the US.

In short, change the fluid.

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-Typos courtesy of my mobile phone.

That seems to be a very common notion. It appears to supported a lot more by hearsay than any real data that demonstrates a definitive "cause and effect" relationship. In my opinion, the person(s) who decided against periodic fluid changes deserves all the credit for "asking for trouble."

You have more chance of varnishing and gumming leaving the old crap in.

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1984 300SD Turbo Diesel 150,000 miles

OBK member #23

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I suggest you find another mech !!
There are only 2 reasons why some one would say that, either they are that lacking in basic mechanical knowledge that they should not be trusted with with working on your car or they are waiting for your trans to fail so they can make some real $$$ from you.
Change the fluid & filter & enjoy your car !!!

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

I agree that you're better off leaving the old fluid in than having it "flushed", which is a transmission repair shop's best friend (lots of transmission troubles follow a "flush" job).

Other than that, change it.

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Gone to the dark side

- Jeff

My mercedes tranny fluid hasnt been changed close to 80,000 miles. the tranny slips here and there but new oil isnt going to hurt nothing.. it doesnt make sense, new oil will surely help and wont hurt it. Thats like saying im afraid to change my engine oil because its to old... My personal opinion. Changing fluids is just the motor or tranny or whatever saying thank you! hahahaha

What i will do is, change my fluid. drive it 5000 miles and change it again. and i believe it be close to a flush because your not going the full amount of miles. Frequent changes should clean it out more.

Not necessary to change it twice if you change the filter and drain the torque-converter when you change the fluid.

__________________

Gone to the dark side

- Jeff

I would put synthetic ATF in it. It's more durable, resists thermal break down, and I have never heard of a case where the trans didn't shift better with it. My favorite is Amsoil, but Redline and Mobil1 are also a quality product.

BMW says the same thing with the ZF ATF's. I have one in a '01 325CiC. They say it's lifetime fluid, special petosin $20 a quart ATF, and you must only use that fluid. There isn't even a dipstick, you have to open the fill plug and pump fluid in there with the engine running, and mostly up to temp, and it's a giant PITA. The factory logic is that a lifetime is about 100K miles. At that point it's too late to service it, it's probably due for a rebuild, and so that's lifteime fluid.

Many of us gearheads say BS on that, get a new filter and fluid in there well nigh of 75K and you can get double the life out of the trans. I did mine at 72K with Amsoil synthetic ATF. What came out was disgusting, and the pan got a drain and fill twice since then, each time getting some gray matter out of it.

We're at 90K with it now and it shifts like a dream. I don't have to worry about overheated ATF, and as long as I drain and fill the pan every 10-15K it will probably go to 200K. Doubt we'll keep the car that long. But not having to invest six grand into a replacement auto-trans is piece of mind.

JMHO, YMMV.

BTW, change of subject, but I just did a drain and fill on my manual trans in the 240, along with the diff. Neither were very dirty, I think they had been serviced at some point in it's 118K mile life. But I'm pretty sure the gearbox had diff oil or something like it in there. I used Amsoil MTF and it shifts like butter now. Very nice, well worth the effort. Besides, they never tightened the fill plug properly so it was obvious some had leaked out, and impossible to know how much 'till you open'er up. May as well do that with my new 14mm allen wrench.

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Chris Brown
"OC", So-Cal
1979 240D, 122K, 4spd, Colorado Biege w/Tobacco, Pwr Roof, AC, Cruise, Becker Corona - SOLD
Past Benzos: 71 250 • 83 240D • 84 190E • 04 C240 • 11 GLK350 • 13 c250 Coupe
http://www.peachparts.com/shopforum/...ine=1276896801

I am a big fan of changing fluids its cheap insurance. You dont need to spend huge bucks on synthecs or pay for a big flush job. Just drain what you can change the filter and fluid and do as often as you will out of love for your mercedes benz diesel. Amen.

'Nuff said!

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2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)

So, are you saying it shouldn't be discussed any further because everything that could be known on the subject has already been written?

Or is this simply a comment in the affirmative of some other comment?

Sorry, I get so confused...

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Chris Brown
"OC", So-Cal
1979 240D, 122K, 4spd, Colorado Biege w/Tobacco, Pwr Roof, AC, Cruise, Becker Corona - SOLD
Past Benzos: 71 250 • 83 240D • 84 190E • 04 C240 • 11 GLK350 • 13 c250 Coupe
http://www.peachparts.com/shopforum/...ine=1276896801

yeah, change differential, tranny (including the torque converter) every year + 3500 mile oil changes. also change fuel pre and main filters every year. 1 can of diesel purge (Lubro Moly) every year.

on the tranny, i bought an '83 300D that had trans fluid in it that was so old it looked like chocolate. not burned, just old. car shifted wierd with a small shudder in the rear end, mostly due to a vacuum issue i was able to resolve, prior to the trans fluid change, but after changing fluids (used Mobil 1 75W-90 in the diff), it shifts silky smooth now with no shudder and i am using it as my daily driver (287k miles, no leaks, and does not burn oil!). rule of thumb when we get these older diesels.... change *all* fluids and filters on them regularly for max life. sounds to me like the guy just didn't want to do the work on your car.

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john
***********
'98 E300 TD "Lukas" 156K
'11 C300 "Mia" 10K, Gorgeous!, Wifey's Car

In many cases, a "flush" is nothing more than a 1:1 fluid exchange. Many "flushing" machines don't even have a pump; they use the transmission's own pump to do the work. No cleaners or solvents are involved.

The bottom line is that "flush" is often just an impressive sounding term for a fluid change. It's probably easier to sell a "$100 flush" than a "$49 fluid change."