2nd Gen Non-Engine/Transmission 3.73 or 4.10 which gear is best?

[LOtero]

i have decided my next BOMB is going to be a gear swap, i want to re-gain the power loss that the 315s stole from me. with a 47re and its . 69 overdrive i am showing to be at 1764 rpm at 75mph with 315s and my stock 3. 55s. 3. 73s will take me to 1853, 4. 10s will put me at 2037. what do you gurus think is the best gear for my rig? i do not tow very often, just the occasional toyota to a trail or boat to the lake. thanks

 

[McCRam]

If I was in your situation, I would go with the 4. 10s. I do not think there would be a big mileage difference between them, I may be wrong about that though, but it will probably drop from your current setup. If you remember what your rpms were when your truck was stock. I would try to get the rpms a little above that

 

[BTighe]

definately the 4. 01's. i wanted to do this swap but the 4x4 shop said it would cost about 1800. last i checked there was a guy in the clasified ads on the tdr that wants to swap his 4. 10's for anyones 3. 54's. he was in florida and i believe his truck is a 12 valve. it has the dana 80 though. enjoy

 

[LOtero]

thanks for the info, i am going to do the gears myself so the price tag should be a hair lower than that WHEW! i am really leaning towards the 4. 10s i come from the offroad world where you always go to the low side of gearing.

 

[BRosser]

gears

3. 73 would be better because it will get better fuel milage 4. 10 will hold speed better with a load but hurts your fuel milage.

 

[LOtero]

i figured on that but it seems the benefits would outweigh the drawbacks, here is the calc that i have been using it is pretty nice.



http://www.nationaldrivetrain.com/calcs/streetcalc.html

 

[SnoKing]

If you drive 75 a lot then 4:10 would be great, 2000RPM is the sweet spot for the 24V. SNOKING

 

[Tcolesanti]

I would definately go with the 3. 73's. Those 4. 10's are too steep for highway driving, even with 315's. I tow ALOT with my rig and I have 315's and 3. 54's, I would'nt trade them for anything but 3. 73's. JMHO.

 

[SnoKing]

I would definately go with the 3. 73's. Those 4. 10's are too steep for highway driving, even with 315's. I tow ALOT with my rig and I have 315's and 3. 54's, I would'nt trade them for anything but 3. 73's. JMHO.

But you have a 6 speed and he has an auto. The Auto has a higher ratio in OD than the 6 speed. (=less RPM for the auto) Changing from 3:54 to 3:73 seems like a lot of cost for a small amount of RPM. And then if he goes bigger yet on tires, he will be wishing he got the 4:10's. SNOKING

 

[LOtero]

thanks everyone, and snoking, you and i are on the same page on this one, i may end up going to 325s and i think 3. 73s are almost not even enough of a change to warrant the work and money.

 

[pwerwagn]

I wouldnt waste the money to go 3. 73's over 3. 55's. I doubt you will notice it. I'd go straight to 4. 10's. besides, I know how you drive, and you dont exactly aim for good gas mileage. Just do the 4. 10's and be done with it. Heck, go 4. 56's and just put 38's on it. Ha Ha.

I have dial indicators/case spreaders/press blah blah blah whenever you wanna do them. I will help. But then you get to help me put 5. 13's in my yellow truck.

 

[LOtero]

GIDDY UP!!! Oo.

 

[Tcolesanti]

Missed the automatic part of the equation. The reason for me wanting to "just" go to 3. 73's is whenever you haul in Commiefornia, its a double nickel speed limit. As soon as you get out of state its hammer down. A little bit of RPM at 55-60mph would be perfect for "me". At cruising speed on the highway, what's the big deal anyway? Last hole in the automatic is overdrive and third is direct just like 5th and 6th on my six speed?????

 

[pwerwagn]

The overdrive is higher on his auto than on your 6-speed.

Were you implying your 5th and 6th are both overdrives? Or saying that 3rd is equivalent to your 5th, and his od is your 6th??? I just wanted to mention that, because a loooot of 6 speed owners think their truck is double overdrive, when it isnt. 5th is 1:1 and 6th is 0. 73:1.

 

[LOtero]

wow pwerwagn you are just a plethora of knowledge! especially for being a young whippersnapper!

 

[pwerwagn]

yeah, well we dont have to worry about short term memory loss, us young whippersnappers (that includes you)

 

[Tcolesanti]

I do know that fifth gear in the NV5600 is 1:1 and sixth is overdrive, and I never implied that my transmission had a double overdrive. The 47re has a . 69 overdrive and the NV5600 has a . 73, Which is pretty close, so they are essentially traveling the same speed at the same rpm. Which in turn would not be that far off for me to lend some advice about a tire size and gear ratio.

100 rpm is the difference between an auto and six speed w/ 3. 54's.

 

[LOtero]

hey guys i really appreciate all the input and i agree 3. 73s are not enough of a jump for the change and the difference in the two overdrives are pretty close, so i will keep posted how this goes!

 

[pwerwagn]

Which in turn would not be that far off for me to lend some advice about a tire size and gear ratio

I know, I wasnt saying that. I was just confused about what you said.

sorry if you took it the wrong way, no harm meant.

 

[Tcolesanti]

None taken.