I own a 1990 300SEL with the 722.351 trans. The transmission is ready for a rebuild but I would like to upgrade it to handle the additional power of the Mosselman twin turbo I will be installing. The power rating of 300 HP puts it in the ball park of a V8 load on the trans.

What I would like to do is convert it to a 722.350 configuration as fitted on the 560 SEL of the same year. The problem is I have been having trouble determining the differences in the internal hard parts, e.g. drums etc, that I need to accomplish the upgrade. I already have a 1st gear start valve body that also has a shift kit in it so I'm OK there.

The other question I have is that the trans whines (not loud but noticable) in second gear only. Other than that it shifts fine. Any ideas what would cause this condition?

Thanks,
Motor Head

I can't answer your question, but if you can tell me what you have done to your transmission, that would be great.

Does it start in first everytime now?

What exactly is the shift kit, and what did it accomplish?

THANKS!

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

I have not installed the valve body yet but the result is that the car will start in first gear every time. The shift kit is installed and takes care of numerous conditions. You have to apply the parts in the kit according to what you are trying to fix.

You can get the kit here:

http://www.superior-transmission.com/products/shift_correction/722A_g.htm

Hope that helps.

OK

Are you sure that the valve body will bolt to that transmission?

There has been some discussion regarding adapotor plates to mate the later valve body with the ealier trans.

I have been tempted to order that kit for a few years now- obviously to soften up the 1-2 shift. Then the valve body modification.

What do you think of the kit? Can you make the 1-2 shift feel normal? As in predictable and not whiplash inducing?

__________________
'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

Each valve body is a custom job. Although the modifications are basically the same you need to provide the year and serial number off your valve body toa competent trans specialist so they can determine what is appropriate. Unfortunately, this is not one of those off the shelf easy upgrades. You will need to do some digging on your own unless you happen to live near Mario Aristides in Miami Florida. He runs Independent Transmission and is the smart guy on Mercedes. He may be able to help you with your questions.
As far as the shift kit I am very happy with it. BTW, Mario designed that kit and Superior sells it. I installed it myself but if you don't have any experience with a valve body you might want to let a shop do it for you.

All of the numbers at Marios shops here in Miami appear to be disconnected. Would you happen to have a number where he can be reached?

__________________
'83 SD, 2x '85 SD
You are entitled to your own opinions, you are not entitled to your own facts.

(786)597-7738

thanks for Mario Aristides' #. would not have been able to get it otherwise.

__________________
'83 SD, 2x '85 SD
You are entitled to your own opinions, you are not entitled to your own facts.