05 WK vs 05 KJ Motor, Trans, and Gearing

[blue_kjR417]

I have a cousin with a 05 WK with the 3.7 and 4 speed auto trans. We're trying to determine what trans he has and what ratio gears he has because he's running 255/75/17 tires I jw how comparable his powertrain is to my KJ's

 

[HoosierJeeper]

I have an 09 WK with the 3.7. It has 3:21 gears and I'm guessing a lower first gear, they have a 5 speed auto.

 

[blue_kjR417]

I have an 09 WK with the 3.7. It has 3:21 gears and I'm guessing a lower first gear, they have a 5 speed auto.

Are you saying my cousins wk has a 5 speed too? That would make since because I drove his with 32's and it still had plenty of power to haul the jeep its self around, now he said when he hooks to a trailer its done for but alone its ok and the 5 speed would make sense given that I determined he has 3.55's

 

[HoosierJeeper]

Yeah it would.It's the W5A80.
https://en.wikipedia.org/wiki/Mercedes-Benz_5G-Tronic_transmission