Actual gear ratio?

[Curly5759]

My build sheets shows a listing for an "Overall gear ratio" of 3:45. Is calculated in overdrive or regular drive (1:1 ratio)?
I want to tow my Travel trailer and I am concerned about power climbing the hills around here. (2023 Sport V6/auto)

Build sheet:
3.45 OVERALL TOP GEAR RATIO DANA M220 REAR AXLE CONV DIFF FRT AXLE W/DISCONNECT

Thanks

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[Zandcwhite]

That's the axle gear ratio, that would be the final drive ratio at 1:1. Our autos are double Overdrive so 1:1 is 6th gear. 0.83:1 is 7th and 0.67:1 is 8th gear.

 

[grimmjeeper]

Yep. Axle ratio. Transmission doesn't factor in to that number.

 

[CarbonSteel]

@Curly5759 - here you go:

 

[blnewt]

You'd have to move up to a Rubicon to get better gearing, that would be a 4.10 ratio. Unfortunately you can't order optional gearing until you go up to the XR packages AFAIK. Hopefully your trailer isn't too large to sap the V6 too much. At least you have the bigger rear differential vs the standard sport, and you'll have Limited Slip back there too.

 

[grimmjeeper]

To add to my previous post...

Towing with 3.45s isn't optimal. The transmission will compensate by down shifting more. You'll spend less time with the torque converter locked up. That means a bit more heat in the transmission and lower fuel economy. But it's possible to live with it.

A regear to 4.10s with stock size tires would be better but that's not cheap to do. And if you're going to put bigger tires on, you'll want to go further.

 

[Curly5759]

Carbon Steel: Thanks!!

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