Mobil MV ATF VS Valvoline ML in a mercedes 722.6?

May 9, 2024
I have an 02 Mercedes SLK320 with the 722.6 5 speed auto.

It has 119k on it... has a bit of some cold shift thunking....

I see in it's history the trans was serviced once at 75k for sure... the fluid is full, smells ok and looks light brown...

Time for a filter and fluid change!!!!

Have access to both Mobil Multi Vehicle ATF and Maxlife MV.

Of these two, what would you choose for an older transmission that needs to last?

The maxlife viscosity worries me a bit???

I can't find too much actual experience history posted with the Mobil product... of course it states it is compatible with this transmission.

Neither of the two are on the mb list as I understand... shell 134 is but wasn't on "my" list as it's a semi vs full synthetic...

Thoughts? I'm driving myself crazy!
If you're looking for a high-quality ATF, I recommend checking out Castrol TranSynd 668. It features the same additive package as other top-tier fluids like Valvoline Extended Performance ATF and Mobil 1 LV ATF HP, incorporating advanced friction modification technology. What sets it apart is its higher viscosity—around 7 cSt at operating temperature—which might be exactly what your transmission needs. From my experience, Castrol TranSynd 668 performs exceptionally well in various transmissions.


For optimal results, I suggest a complete fluid replacement. If it's not feasible to replace all at once, consider performing three consecutive drain and fill processes. This approach helps integrate the new fluid more effectively.

Another excellent option is @High Performance Lubricants ATF Blue (or Blue CC). The Blue CC version is formulated with PAO, while the regular version uses Group III base oil.

You can find more information and purchase these products at the following links:
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Welcome to BITOG 🥳

Use the Mobil ATF. It mentions Shell 134 and relevant MB specs and is not an ATF/CVT combo

There was a TSB saying Maxlife could be used, but Valvoline recently reformulated it to become an ATF/CVT combo fluid :cautious:

This transmission came out in the DaimlerChrysler era, and Chrysler used that transmission in many of their cars and spec'd ATF+4

Here is the older TSB that mentions Maxlife before it became an ATF/CVT combo:
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Stick with the Shell 134. Use something else and you are asking for trouble. The MB forums have lots of shifting problems when people use Maxlife. Valvoline says it is ok to use and people on here will tell you it’s ok but it is not. The transmission was designed with the 134 fluids in mind.
I have the same slushbox in my W210 and have used Castrol Transmax full syn multi-vehicle with good results. That transmission is not picky, however staying with Shell 134 is not a bad idea. It will respond well to a filter change, while you're down there replace the 13 pin transmission plug with an OE one.

WOW! Thank you ALL for the replies! I welcome any additional information!!!

The transmission has a clunk when cold... either a sticky solenoid, the conductor plate possibly or... what I'm thinking and hoping -- poor fluid, wear and a plugged filter.

I have the connector already along with hengst filter.

My plan is to to the filter and fluid now then change the fluid every 5-15k after...

My goal was to find an affordable and sourceable fluid.... the mobil, shell and Castrol are all in the same price category for me. The mobil is what I currently have on hand.

My thoughts are just hurry up and service this thing with valvoline or mobil... then ongoing perhaps swap to shell 134 or Castrol and continue to drain and fill.
Feeling I may go with the mobil out of the two and then Castrol for drain/fills.
Seems mobil may be the better bet for now...

But I now know... if it explodes 500 miles later, it most likely won't be the fluid I used... it was already destined to grenade.

Does anyone have ANY Solid answer on the capacity of the transmission?
Filter change and just a drain and fill?
i wont be draining the TC.