Iīve heard that JEEP is working on a new TSB for the transmission on JGCSRT8īs. It seems that the revs are too high at highway speeds:

Does this happen to you? Do you have the following RPMs at the following speeds?

60 mph: 2200 rpmīs
70 mph: 2550 rpmīs
80 mph: 2850 rpmīs

These are way too high rpms for a big motor like the SRTīs If youīve got different numbers post them so that we can better gauge the situation.

What rpmīs at those speeds do you get?

LOL

and why are these numbers too high? while I will agree a 6th gear for the highway would be nice.

"LOL" because your joking??

373 gears will do it

Too high? Is this a joke?

Iīve heard that JEEP is working on a new TSB for the transmission on JGCSRT8īs...
No WK tranny updates/TSB's are currently in the works...

I think there should be more than a 500rpm difference in engine speed between 4th and 5th gears, especially with how much power the 6.1 makes throughout the power band. I was actually surprised the first time I shifted into 5th - the tach barely moved.

Are these transmissions based on the previous-generation Mercedes E-Class? I know that there are a couple members who have E55 AMGs, maybe they can chime in to tell us the differences at 60mph between 4th and 5th gears just for comparison's sake?

Regardless, I don't believe a software update will change the physical size of the gears...you'll have to start taking stuff apart for that.

-Matt

Yeah, this TSB would require a 3.55

Can the gear ratios be changed on these SRT8īs?

Can the gear ratios be changed on these SRT8īs?
Of course. You need to buy a different gear set and have it installed. Your Jeep will be slower, however, so why would you want to do it? Are you really that concerned about the rpms?