What is the Lifespan of a well maintained W123 300D transmission? - PeachParts Mercedes-Benz Forum

Carrameow · #1 11-22-2005, 12:33 PM

What is the Lifespan of a well maintained W123 300D transmission? Its winter project time, and I was thinking of rebuilding my old failed unit. I got about 320,000 on my previous unit which came on the car when I bought it, but it had a trailer hitch on it...the one I replaced it with had 212K on it, but I don't think the maintenance was that good because the fluid was practically brown.........

#2 11-22-2005, 01:00 PM

I don't know how well the PO maintained my 300D tranny, but it was starting to flare around 200K and I replaced it with a reman. at about 250K. Hopefully, the new tranny will do better. I'll let you know in about 200K miles.

Stinkindiesel · #3 11-22-2005, 01:59 PM

Quote:

Originally Posted by Carrameow

What is the Lifespan of a well maintained W123 300D transmission? Its winter project time, and I was thinking of rebuilding my old failed unit. I got about 320,000 on my previous unit which came on the car when I bought it, but it had a trailer hitch on it...the one I replaced it with had 212K on it, but I don't think the maintenance was that good because the fluid was practically brown.........

I got 168Kmi out of the first transmission, but that one died due to a leaky cooler hose and an inattentitive teenage driver. Probably would have been good for quite a bit more otherwise. I've got a neighbor with 365Kmi on the original in his 1985 300SD.

Zerohour3k · #4 11-22-2005, 02:44 PM

Is the cooler hose, that "hiss" sound I hear, while accelerating from a stop? Sounds like it's coming from below the driver's dash. Is that good?

rg2098 · #5 11-22-2005, 02:49 PM

220k with mine, it slipped from 2-3 a tad and made worse by the harsh 1-2 shift. I ended up replacing it when the B2 broke for $1200 for comfort reasons but I estimate I could have babyed another 50-70k out of it.

Hatterasguy · #6 11-22-2005, 02:53 PM

My SD had its trans done by the po at about 150k but I don't know the exact mileage.

The SDL is still on the orignal at 254k and it shifts pretty well. I would be surprised if it doesn't need a rebuild before it rolls over 300k.

A lot depends on the driver and how the car was driven. Highway travel wears a trans much less then around town driving.

phidauex · #7 11-22-2005, 02:53 PM

It seems like most last around 250k, but some get a little more.

Mine was starting to misbehave a bit around 240k, and was rebuilt. Works wonderfully now at 260k.

peace,
sam

cpm · #8 11-23-2005, 10:37 AM

Does 'flaring' mean the xmission is done?

I was hoping that when I get the oddball vacuum issues sorted out that
my 318K 83 300td xmission would calm down.

Mine 'flares' betwixt 2-3 and 3-4 sometimes. If I manually shift it, it doesn't do it.

It also 'chunks' into reverse. I was thinking that once i sort out the vacuum, and
fiddle the modulater some, , , well, maybe that's wishful thinking.

What's a reasonable price to pay for a rebuild? I have no sense of these things.

diver · #9 11-28-2005, 11:40 AM

I wonder what influence good maintenance/oil type has on the trransmissions? Both my cars, the 84 300TD and the 85 300 SD Turbodiesel have just under 300K miles. both have the original transmissions. I change oil about every 30 K miles. Never used synthetic oil.

Would it be recommended to continue as before or change to synthetic oil now? Are the seals, hoses etc. compatible for synthetic oil?

If you recommend a change to synthetic, what type would tyou recommend?

What are the high milage/no problem transmissions on the forum?

Lots of questions in hope to get more miles out of my trannies.

tenknots · #10 11-28-2005, 12:47 PM

408k on Strider.

diver · #11 11-28-2005, 01:02 PM

Are these Miles or Kilometers? Synthetic oil or standard Transmission fluid?

pawoSD · #12 11-28-2005, 03:29 PM

231k on mine so far, changed over to synthetic fluid 2 months ago, also had the seals all redone by the dealer at 212k, and they said it looked great inside and should last a long while yet. With my vac probs fixed it no longer flares, ever. Seems to work great. I am shooting for 300k+!! The way it is running currently I see no reason why it shouldn't last at least another 70k.....

tenknots · #13 11-29-2005, 01:31 PM

Miles for mine. Only conventional has ever been used BUT, it was always MB brand. Maybe that's the trick.

#14 11-29-2005, 01:33 PM

Aren't they suppose to last a "MILLION MILES?" lol

diver · #15 11-29-2005, 03:21 PM

Thanks TENKNOTES, very re-assuring! I'll try and follow, will stay with standard transmission fluid and hope to make it a million miles! Half a million may be all right too!