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3.08 gears

4.5K views 5 replies 4 participants last post by  Copperhead  
#1 ·
hello, I recently traded my 2012 silverado in on a 2015 midnight ltz crew. my 2012 had the 3.42 gear ratio 5.3l and had more than enough power for what I used my truck for. the new truck has 5.3l but 3.08 gears. I only have 400 miles on it so far . will this compare to what I had? I do have more hp now, or should I have my gears changed? would a tuner help? thanks.
 
#2 ·
No..

they put a 3.08 gear in there purely for mileage. while not a HUGE difference to 3,42..its enough to lessen the struggle on the transmission.

personally i would upgrade if you have the money. something like a 3.73-4.10

you will be a dog trying to tow, let alone get any performance out of a 3.08, unless you have a high stall converter, lower aftermarket gears in the transmission. in which i 100% doubt you have either, 4/6 speed regardless

a tuner will help a little bit, but wont cure the problem, your motor may have more power, but the stress is on the transmission, not the engine.

swap gears if its in the budget
 
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#3 ·
Might want to keep in manual mode more frequently to control the shift points to better match performance to what you are doing. That would be a big help in many situations. You will notice a difference, for sure, compared to your previous ride, but like most things, once you learn where the motor likes to operate and how to manage power to what you are doing, it may not be that bad of an issue. I personally do not like taller rear ratios for many applications combined with one size fits all motor and transmission combinations. I use very tall ratios (2.64 - 2.79) in my commercial trucks (and I have transmissions with 18 gears that I can make it all work well), but like lower ratios (3.73 - 4.10) for my pickups. But, one can overcome limitations with a little trial and error, using the manual mode more frequently and taking more control over from the TCM. Of course, if you can't seem to grow happy with the setup, you could always do a gear change. try the other stuff first to save some money.
 
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#4 ·
Regardless of the gearing a tuner can give you more pep on take-off by disabling the torque management, it made a night and day difference on my truck. Plus with the tuner you can disable the AFM if you wanted too. I'd try a tuner first before dropping a giant wad on gears.
 
#5 ·
it should be noted that most commercial/ semi applications that engines have a 2500-3000-ish RPM cap. and that you have 10-18 speeds which gives you that pulling power, so a 2.70 range gear is appropriate in alot of commercial applications.

Some of them do have gears in the 3.55 range aswell.

you "shouldn't" have to run in manual mode all the time, just to get happy shifting.

its it was my choice.id do gears, then if you needed more, get a tuner.

though i was happy when i had my K5 with a 305, th350 and 3.08 gears and i could smoke hondas...but then gain i had a built transmission with a 2800 stall.
 
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#6 ·
Well, most of the newer commercial semi engine are governed to run not more than 2100-2200 RPM. most of them do their work at 1300-1500 RPM. 3.55 is a common ratio with overdrive transmissions. Many direct drive trans in use now with 2.64 as a typical ratio. My 18 speed is a double OD, but I run it primarily in 16th direct at road speed. The key, is being able to split the bottom range gears and keep the RPM's in a 200-250 RPM operating range of each other. We don't quite have that luxury with our pickups, and the RPM spreads are a lot bigger with tall ratios, even with the 8 speed. all of that nonsense being said, I have found 4.10 to be the ideal ratio for most everything I have done with a pickup for decades. I invented new swear words on the 3.42 in a 1500. One of the reasons I am back in a 2500 with 4.10 again.
 
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