Will the transmission in a 1991 420 SEL fit my 1990 560 SEL????

[ron59b]

Good evening all,

I purchased a 1990 Mercedes 560 SEL for $700.00. There are four things wrong with the car:

1. Transmission slipping in reverse.
2. Driver window motor is weak and requires assistance when putting the window up.
3. Need a fuel pump relay.
4. Needed a battery.

I was at the bone yard yesterday and found a 1991 Mercedes 430 SEL that was in outstanding shape. I found a receipt inside showing a transmission service within the last year.

The question I have is weather or not the transmission will fit in my 560 SEL? I have someone ready to pull it for me tomorrow. Do you think the switch could be a DIY job?

Any feedback would be greatly appreciated.

Thanks

Ron

[pmckechnie]

Yes, it will fit. I know that a 89 420 has a 722.355 and a 90 560 has a 722.350. I have no idea what the difference is but must have something to do with engine characteristics as the cars are the same weight and size. I have a 89 420 722.355 in my 84 500 and it has worked great for the last 60K miles in this car. Right now, it also has no reverse. Going into shop today. The "no reverse" seems to be a common problem on these transmissions. Some say to rebuild, and some say just fix it. The reverse clutches are in the front of the transmission and easy to get to after the trans is removed. I don't know which my trans will get (rebuild/fix) yet. It depends on what it looks like when he starts into it. We will see.

Paul

[ron59b]

Paul,

Thanks for all the helpful information. Let me knwo the outcome of the transmission work too.

Thanks

Ron

[ron59b]

Good evening all,

I have my 1990 560 SEL Mercedes and the reverse is failing. When I first start it up, sometimes I can get it to back-up with letting the engine rev up. Also when I do, I get some smoking and looks like oil leakage. When the transmission is in reverse, it shake initially when beginning to move.

I have a couple of related questions:

1. Which repair would fix it, and would it require the transmission being g removed?

2. I have a spare transmission out of a 1989 420 SEL. The transmission is covered in my back yard. Is there a problem with it sitting, I noticed some rust on the touque converter.

Thanks

Ron

[Das Benz]

To repair the reverse, yes the transmission needs to be removed. It involves removing the front pump and you cant do that while it is in the car.

The 420 trans you have should work fine. The main difference betwwen the 420(722.355) and 560(722.350) is the 560 trans has an additional clutch disk in the drums compaired to the 420, its to handel the higher torque of the 5.6l when your punching it. The 420 trans might get worn out quicker when installed on a 560 but it should be marginal and just dont race the daylights out of it. Lol
Fitment and hookup is identical


I just went thru swapping the trans in my 420 last week, its a day job if you dont have a lift

[ron59b]

Does it matter if there is surface rust on the toqure converter? I noticed the tarp I had in it is getter worn and leaking. Also I have an oil leak when trying to reverse and reviving the engine. What do you think is the source of that leak?