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W123 Automatic transmission advice needed
I could use some advice from the automatic transmission experts out there.
I have an 80 300TD with an OM617 NA and automatic transmission. The car has been sitting for about a decade so it only has 265k. However it will need some major maintenance and brake work before being put in service. So far I have only yard driven it and the other day I noticed a slight shudder when going into reverse. I have no direct experience with Mercedes automatics outside of a few short drives. I much prefer a manual transmission and I have all the parts to convert this car but my daughter will need to drive it and hopefully my son will learn on it. My questions are what can I expect from this transmission generally? Is 265k near the end? Outside of a filter and fluid change what maintenance items and adjustments are critical to longevity? For instance, should the B2 piston be replaced preemptively? I'd like to freshen the transmission and squeeze another 25k out of it if possible. Am I nuts? Wait I can answer that last one! Any help is appreciated.
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1969 220D 5 Speed (OM616) 1983 240D 4 Speed 1985 300D Auto 376K 1985 300D Auto 275K |
#2
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Assuming your car has its original drivetrain, the 1980 300td NA has a 722.118 transmission.
The version of the .118 used on 1980 NA cars is different from other models as it has no Bowden cable or throttle linkage connection to the transmission. Shifting is basically controlled by vacuum and an internal governor. I don't know what would cause the shudder going into reverse, internally, but a worn or broken transmission mount could give something like that. These units are as long lived as any other Mercedes automatic. The answer to longevity lies more in how it was treated on the way to 265k, than what you do now. That is how I see it, anyway. Best to change the transmission fluid and filter, then drive it and report how it performs.
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Mac 2002 e320 4matic estate│1985 300d│1980 300td Previous: 1979 & 1982 & 1983 300sd │ 1982 240d “Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22 |
#3
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Do you know if it is the original trans, or if it has been rebuilt sometime ago?. It is really just a crap shoot if no records have been kept. It may last a week or 10 years, you just don't know. As said, a filter and fluid change wouldn't hurt.
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All Diesel Fleet 1985 R107 300SLD TURBODIESEL 2005 E320 CDI (daily) LOTS of parts for sale! EGR block kit http://www.peachparts.com/shopforum/diesel-discussion/355250-sale-egr-delete-block-off-plate-kit.html 1985 CA emissions 617 owners- You Need This! Sanden style A/C Compressor Mounting Kit for your 616/ 617 For Sale + Install Inst. Sanden Instalation Guide (post 11): http://www.peachparts.com/shopforum/diesel-discussion/367883-sanden-retrofit-installation-guide.html |
#4
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I think you pretty much answered your own question. Remove and discard automatic transmission, swap in the manual, teach the offspring to drive it, and enjoy.
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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar. 83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles 08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles 88 Jaguar XJS V12 94,xxx miles. Work in progress. |
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Thanks for the replies.
I know it's always a crap shoot and even though the maintenance record is very good it ends at 200K so who knows. Since I know so little about these transmissions I wanted to be sure there wasn't some hidden "gotcha" or "they all do that" issue. Skippy - I'm getting some resistance to that idea but it's my preferred approach. I guess I'll run it and be ready for a swap if it lets go!
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1969 220D 5 Speed (OM616) 1983 240D 4 Speed 1985 300D Auto 376K 1985 300D Auto 275K |
#6
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Generally speaking the 722.1 suffers from front pump trouble and knackered splines on the planetary gear castings - though so far I've only really heard about that from transmissions fitted to diesel engines. This could be because "diesels" tend to get driven further and many / some "diesel owners" tend not to look after things as well because owning a diesel is all about economy...
...I'm guessing you've got an early 722.118 with a throttle linkage and an adjusting screw instead of a vacuum dashpot. But the first thing to do is to check the serial number on the side of the casing. At 256,000 miles it could have something totally different in there. If that is genuine mileage and an original not rebuilt transmission then that has to be a record. For more 722.118 related information I started this thread 722.118 Automatic transmission rebuild (Monster DIY)
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1992 W201 190E 1.8 171,000 km - Daily driver 1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone 1965 Land Rover Series 2a Station Wagon CIS recovery therapy! 1961 Volvo PV544 Bare metal rat rod-ish thing I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior Don't leave that there - I'll take it to bits! |
#7
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Thanks for that information. I have much to learn about Mercedes automatics! My transmission doesn't have any throttle linkage or cable. It's the type with vacuum control only. According to Zacharias it's a 1980 only part though I'm sure I could swap in another model using the appropriate linkage.
I'll tune it up and see where it takes me. If it dies and I can't convince my daughter to go with a 4 speed I'll work through it using your huge DIY on the subject. While I'm at it I want to thank for all your DIY's. I've learned a great deal!
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1969 220D 5 Speed (OM616) 1983 240D 4 Speed 1985 300D Auto 376K 1985 300D Auto 275K |
#8
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I am not sure if the .118 in the form you have it (vacuum only) is exclusive to 1980, but I suspect so. I believe the '78s and '79s had the version with no vacuum and throttle rod.
Just FYI, the .117 version of that transmission is also vacuum only and was used in the four cylinder w123s (240d). It is not considered a direct interchange but I have one in my 300td right now, after my .118 died.
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Mac 2002 e320 4matic estate│1985 300d│1980 300td Previous: 1979 & 1982 & 1983 300sd │ 1982 240d “Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22 |
#9
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Quote:
Quote:
Another example I recently sent someone a replacement 722.112 valve body but we found out that there too is a difference between early and late... ...pain in the arse!
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1992 W201 190E 1.8 171,000 km - Daily driver 1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone 1965 Land Rover Series 2a Station Wagon CIS recovery therapy! 1961 Volvo PV544 Bare metal rat rod-ish thing I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior Don't leave that there - I'll take it to bits! |
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