Lifetime Premium Member
Date registered: Jan 2006
Vehicle: About a dozen 1988, 1989, 1990, and 1991 sedans, wagons, 4Matics and 1 coupe
Location: Just west of Philly
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Quoted: 52 Post(s)
1) Is your avatar a picture of Jeff Lynne?
2) I've said forever that the transmission is the Achilles heel of the 124 Benz. Even when the car is new the lack of overdrive causes the engine to rev too high (which it is quite happy to do) at highway speeds but it just kills any hope of good fuel economy. The transmission will last 10 years/100,000 miles no problem but when the car reaches relatively cheap transportation price levels a transmission problem that requires overhaul is so expensive that it sends teh car to the junkyard. Of the 5 or 6 124s I've driven over the past 17 years every single one has required transmission replacement. Sometimes I had to do that and sometimes the PO had it done.
My red 260E/300E had leaks from several places and I addressed them one by one. The output shaft radial oil seal developed age cracks and made a mess. I replaced that with the car on a friend's hoist so it wasn't too bad. I had leaks from a side cover that hid the secondary oil pump. I had to disconnect the exhaust system, remove the trans crossmember, and tip the trans rear end down far enough to remove and install that cover. I fixed the leak but soon thereafter the trans failed. I still don't know if I caused the failure or if it was going to happen anyway at that mileage. The blue 91 coupe I bought last year has a bad trans. The white 88 300E I bought 3 years ago had a bad trans, the black 91 300TE 4MATIC I bought as a parts car a few years back had (you guessed it) a bad trans. I could go on.
If you're dealing with only a leak from the pan or the output shaft you're in luck. After that things get ugly. But at least you're fairly close to Sun Valley transmissions, a well respected rebuilder. Well you're a lot closer than I am anyway...
I just thought of something else that's an easy fix. The kickdown solenoid is externally mounted on the transmission and the plastic housing of that part cracks with age. It will cause a moderate nuisance oil leak but can be fixed easily and cheaply with a new solenoid.
Last edited by augapfel; 07-27-2019 at 10:57 AM.