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Discussion Starter #1
1989 420SEL WDB1260352A
Transmission: 722355 03 275716
Klms 296,000

What can cause a Solenoid to run poorly?

Are you able to replace the solenoid without removing Transmission out?

Transmission has been serviced but my gears are rough when shifting and put it in reverse it delays for 2-3 seconds. I was told it was due for a rebuild but it shifts perfect at every revs and runs beautifully on the highway.
 

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1991 500SEC sub 50K mi. 1987 560SEC Now 150K mi. 2018
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4,207 Posts
1989 420SEL WDB1260352A
Transmission: 722355 03 275716
Klms 296,000

What can cause a Solenoid to run poorly?

Are you able to replace the solenoid without removing Transmission out?

Transmission has been serviced but my gears are rough when shifting and put it in reverse it delays for 2-3 seconds.
I was told it was due for a rebuild but it shifts perfect at every revs and runs beautifully on the highway.
Your "put it in reverse it delays for 2-3 seconds" kinda says it all... Looking at the total distance covered as well.....

While I am not a transmission expert by any means, it's fair to say the transmission is trying to tell you something here.
Other BW W126 members, over the years, have mentioned the very same failing only to find transmission overhaul/replacement nessasary in the very near future.

I suppose a transmission filter & flush might be a good idea to first run up the flagpole as it were..... but I am not particularly enthusiastic about the outcome ..

Once, some time ago, I had a high mileage car with the auto transmission displaying bad symptoms.. I ordered an exchange unit from the dealer and had both the car & 'new' transmission delivered to the shop.

The results were just great.

MBL
 

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1986/1990 W126
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13,575 Posts
I thought the same, rebuild on the box was the best money I spent on the car. It had leaked badly for ages though so wasn't in the best condition.
Almost a shame the OP's transmission functions well otherwise. Reverse does normally seem the first to give up the ghost though.
 

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1985 300 TD 1981 300 SD
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348 Posts
The reverse clutches wearing out is related to the design, they are a large diameter and sit right behind the front pump with the apply piston riding lightly on them and see high rotational speeds along with corresponding friction from the stationary steels when not engaged and it causes them to eventually wear out while the forward frictions show almost no wear. The fact that all of the friction material can be worn off of the reverse clutches and the transmission will still engage reverse though delayed is a tribute to the overall design of the 722.3 & 4.
 

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1991 500SEC sub 50K mi. 1987 560SEC Now 150K mi. 2018
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4,207 Posts
The reverse clutches wearing out is related to the design, they are a large diameter and sit right behind the front pump with the apply piston riding lightly on them and see high rotational speeds along with corresponding friction from the stationary steels when not engaged and it causes them to eventually wear out while the forward frictions show almost no wear. The fact that all of the friction material can be worn off of the reverse clutches and the transmission will still engage reverse though delayed is a tribute to the overall design of the 722.3 & 4.
Thank you for that excellent, clear description. I have never heard it put just that way.

M
 
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