Xeron

Does anybody know what the transmission differences are between the SL55 and the SL 500. Internally, how much diffence is there between the two?

jettie1767

Starting in 2004, the SL500 is 7-speed. The 55 is still a 5-speed.

doltmo

The AMG 5-speed has a manual mode - not offered in the 7-speed.
The 5-speed can handle more torque.
The SL65 5-speed is beefed up over the SL55 version.

mbbodytech

They are tow totally different units. The seven speed (or 722.9 trans to be specific) first variant introduced was for the 113 5.0 liter engines. The version for the six cylinder was next, and the SLK 55 (naturally aspirated 55) was the very first AMG to get it. Eventually they will replace the five speed (722.6) in the high horse power vehicles to the new one. Put it this way, when the AMG version of the 164 is introduced, they will have to put a 722.9 in it because it has the "shift by wire" system that will never be seen on the 722.6.

blueSL

The 722.6 dates from the mid 90s and was the first electronic 5 speed with the W-S rocker switch. I had one in a previous generation SL600 and it failed big time last year. That gearbox, in modified form (including replacing the parts which failed in mine), made it through to the early R230 SL500 and is still used in the SL55, of course with a modified shift program.

Xeron

they're changing the master control unit and the valve housing

Trimmer2

Slightly off topic but, my understanding is that the SL55 and SL600 are both physically the same except for some possible electronic shift points. Not only is the SL500 now a 7 speed but, it also has more aluminum bits as opposed to the steal used in the 55 and 600.

taroliw

Sorry to revive an old thread, but this is of some interest, as there has been some question regarding the actual differences between these versions. There is a feeling that they may well be mechanically identical but only differ in the control module or even just firmware (seeing as it's flashable). Can you confirm, or perhaps point me in a direction to get more info on this?

implausible

The .9 and .6 are totally different internally. The .9 uses a magnesium case, requiring aluminum bolts everywhere on the case. The .9 also houses the trans control unit on top of the valve gear. The .9 oil level correction procedure requires an SDS to monitor oil temp as well as special equipment (7G tronic filling station or similar). The initial fill procedure is a two stage operation. Currently there are only a few remedies for transmission shift quality complaints. A)Oil level incorrect, B)Shift adaptation, C) Valve body replacement, D)a jumped circlip in the B1 brake, which involves opening the tranny. E) replacement of the entire transmission.

Hope that helps...

taroliw

Agreed. My post was actually regarding different versions of the .9.