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Discussion Starter · #1 ·
I just bought a 06 6 speed and was woundering what ratio is in my rear.

At 70 my rpm is 2200


What is your 70 rpm, and you rear ratio.

Thanks all for your time
 

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Sounds like 3.73 to me. I have 06 with a 6 speed and 3.73 and thats about were I am. GSHARK, GOOD LUCK with the truck!!! :thumbsup
 

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yeah sounds like 3.73, at about 2 g's you should be under 2000 rpms
 

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put it on a lift, mark the tire and the drive shaft, and hold or turn both tires at the same time and see how many times the drive shaft turns compared to your wheels and there is your ratio.
 

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if they havent been changed out, there should be a sticker in the glove box telling ratio. :thumbsup
 

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'06 trucks don't have the sticker in the glove box (mine didn't from new). They also only had one rear gear from the factory for 6 speed manual trucks and it is 3.73:1. Your RPM are exactly what mine are and I have the 3.73's in my truck. If you plan to tow heavy you will love the gearing, if you plan to run empty at speeds over 65 you will not like your economy.
 

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Discussion Starter · #9 ·
'06 trucks don't have the sticker in the glove box (mine didn't from new). They also only had one rear gear from the factory for 6 speed manual trucks and it is 3.73:1. Your RPM are exactly what mine are and I have the 3.73's in my truck. If you plan to tow heavy you will love the gearing, if you plan to run empty at speeds over 65 you will not like your economy.
Can they be switched to 3.42:1 or so? And how much will that affect my rpm at high way speed?
 

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sounds like you have 3.73's

3.73's give me decent economy, usually get 20 - 21 hwy empty.
towing is grrrrrreat with that gear set up. pulled 24 ft cattle trailer with five
700 lb calves and got 13 to the sale.
 

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i wouldn't switch to 3.42 with the size tires you have.
 

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I just bought a 06 6 speed and was woundering what ratio is in my rear.
In the 05's there is a sticker inside the glove compartment. It's a rectangular white and the print on the sticker could be a bit faded. It maybe stuck in the Dodge book or even laying in the bottom somewhere because the adhesive is shot. That sticker will show your R&P. All the dually's I've seen, that deals with friends, have 4.10's. I haven't seen one yet w/ 3.73's. It is possible, options.
 

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3.42 gears are now available for our trucks, but they are pricey and would take a long time to pay for them selves in fuel saved.
 

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easier to go with a larger tire. I have an 04.5 manual w/4.10's. that gives me roughly the same final wheel ratio as your G56 w/3.73's. I just installed 315's and that lowered my running RPM's nicely. instead of 2000 being 60mph, 2000rpm now equals 68mph :D

fuel economy hasnt changed which I guess is a good thing. just made a 700mile round trip vacation in beasty and had an overall average of 18.2mpg hand calc and that was running 70-75mph the whole way loaded(500lbs of gear)
 

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Discussion Starter · #16 ·
thanks all for your time.

I think I will stay with what I have. Yesterday I towed my travel trailer (9000 lbs) and I had to leave the trans in fifth gear because rmp too low in sixth running 70.

And I got somewhere around 9.2 mpg with trailer and 18.9 without
 
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