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Stronger automatic trannies? - Printable Version

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Stronger automatic trannies? - biggriz86 - 08-07-2008

Hello all, I was wondering about the automatic transmissions in the 300CD cars in particular and the turbo diesel mercedes in general.

I was wondering if there were any high performance rebuild kits or tricks available to improve the lifespan and performance of the auto trannies. I know the race spec 700R4 was by far the biggest seat of the pants improvement to my camaros performance. But it included a full high performance rebuild with heavy duty clutch packs, a corvette 1st to 2nd servo, a stage II shift kit, and a 2600rpm stall converter with a kevlar luckup clutch. What is the designation for these transmissions, and what companies (probably in germany or something) sell performance parts for them?

thanks Wink

Re: Stronger automatic trannies? - winmutt - 08-07-2008

You should be able to increase the modulator pressure to account for increased power. Otherwise the options are pretty limited. This same transmission was used in Porches, so it has to be pretty decent. Remember transmissions and what not are rated by torque not HP.

Re: Stronger automatic trannies? - ForcedInduction - 08-09-2008

Supposedly the clutch packs from the 722.3 or 722.6 used on the 600 series (V12) can be swapped into the stock transmission without any electronic controls. The 6.0L V12 M120 put out 400-428 lb/ft of torque.

The 722.x series are amazing transmissions. They were introduced in 1970 as the 722.0 and are still in use as the 722.6 in every MB and several Dodge and Chryslers. New MBs use the 722.9 7-speed.

Re: Stronger automatic trannies? - GREASY_BEAST - 08-27-2008

Found at blueridgemb.com:


Quote:722.6Â’s modified to handle over 800HP!

Improved clutches/oiling/pumps makes a substantial increase in power handling possible.

We can also adapt a .6 to your earlier 4sp (722.3) Mercedes with a stand alone controller. Add a 5th gear for economy and have the above modification for added power handling capacity.

Please call to discuss your needs/wants/pricing.

(404) 805-1357


Re: Stronger automatic trannies? - winmutt - 08-28-2008

What is the 722.6 from?

Re: Stronger automatic trannies? - Tymbrymi - 08-28-2008

winmutt What is the 722.6 from?
I believe it is the one used in my CDI. Hence the standalone controller comment... My guess is that controller would be pretty pricey. Then again, so would modifying the transmission (and building an engine) to handle 800HP!!

Re: Stronger automatic trannies? - ForcedInduction - 08-29-2008

Here is their website.
<!-- m --><a class="postlink" href="http://www.blueridgemb.com/">http://www.blueridgemb.com/</a><!-- m -->

I wouldn't expect such a modification to be low cost. It would be up there with a Myna pump.

Re: Stronger automatic trannies? - GREASY_BEAST - 09-01-2008

all things considered, if it cost the same as a myna pump, I would do this mod over getting a myna pump.... and then get a myna pump.... oh if only my disposable income match my ambitions..

Re: Stronger automatic trannies? - ForcedInduction - 09-01-2008

Yes, get the transmission first. There are many other power adders (VNT turbo, intercooler, W/M injection, propane, etc) that can bring torque up to the limit. No point in getting a power pump first if you can't use it!

Re: Stronger automatic trannies? - Lincolnlock - 10-24-2008

What can we do to our stock transmissions to get some more holding power? I've already adjusted the vacuum regulator down to quickin the shifts. I'm pretty sure it's at it's limit right now and I haven't even touched the internal pump settings yet.

Re: Stronger automatic trannies? - ForcedInduction - 11-30-2008

Lincolnlock What can we do to our stock transmissions to get some more holding power?
You can increase the modulator pressure. How, I don't know. Maybe somebody that does (KTA-Cummins) will speak up.

I hear the later 722.6 guts can be used to rebuild the 722.3 so it can handle extreme power. The 722.6 was used behind the M120 V12 and takes upwards of 400ft/lbs of torque!

Re: Stronger automatic trannies? - GREASY_BEAST - 12-01-2008

found this

<!-- m --><a class="postlink" href="http://www.mercedesdismantlers.com/722.118_transmission_adjustments.html">http://www.mercedesdismantlers.com/722. ... ments.html</a><!-- m -->

I don't know if there is a similar thing on 300D transmissions or not. It seems like it would be located somewhere near where the bowden cable meets the tranny, but who knows... can't tell from the damn picture what the hell he is adjusting!!

EDIT: Disregard the previous nonsense. Wrong transmission. Here is the right one:

<!-- m --><a class="postlink" href="http://www.mercedesdismantlers.com/722.3and722.416_transmission_adjustments.html">http://www.mercedesdismantlers.com/722. ... ments.html</a><!-- m -->

and the adjustment appears to be located where the vacuum tube meets the transmission!

Re: Stronger automatic trannies? - Section106 - 12-23-2008

Has anyone ever mated a 727 TorqueFlite or LoadFlite to a Super Turbo Mercedes engine? The Load Flites are used with the Cummins 5.9L from the factory.

RE: Stronger automatic trannies? - SurfRodder - 05-27-2009

Is there a way to fit the guts of a 722.9 into a .3? That would be the way to go.. then you could run a 3.07 rear and still have good topend... from a first gear ratio of 13.44:1 to a 7th speed of 2.23:1...that would be pretty sweet...

maybe a bell housing modification would be easier... but if the internals are laid out the same/similar, it might be the way to go.

plus it just so happens that I have a .3 assembly thats completely toast that I could gut for the hell of it...

RE: Stronger automatic trannies? - MB TECH - 05-27-2009

I highly doubt dot 9 guts would fit in a dot 3 mainly because the shift member bolt patterns and the front pump are different.
plus the dot 9 is magnesium bell housing.

RE: Stronger automatic trannies? - ForcedInduction - 05-27-2009

No way you could get a 7-speed inside a 3-speed housing. The 722.9 is a monster.

[Image: image007.jpg]

I wouldn't mind finding a 5-speed auto and getting a cheap standalone computer for it. It would probably be cheaper than a 5-speed manual.