4.10 vs. 3.73

[T.I.]

Just wondering what the pros and cons are accept for less fuel mileage??

Thanks

[NWTDIESEL]

When putting 4xx on all your doing is trying to get the gear ratio back to 373 when adding larger tires. I know a few guys that have done this on there lifted Dodges/Dmaxes and all of them wished they didnt do it cause they can only go 100mph while pushing 3500rpm.

[T.I.]

My truck came with 4.10's from the factory. Just didn't really know why it would. Does it help the tranny hold more torque or hp if it was running stock tires??

[RickDLance]

I assume its a gas powered truck?

[blksmok]

Todd,
To my knowledge all Duramax Allison trucks come with 3.73 from the factory. No other gear ratio is a factory option...

[RedBowTies88]

x2^..........

check for rpo code GT4/GT5and report back

[Royce]

so you guys would say not a good idea to go to 4.10 with my 37's since im on the highway a lot??

[RedBowTies88]

i dont think its necessary....you have a 6 speed so its wont be a bad thing but i dont its worth the money/effort

if you had a 5 speed i would say forget it completely...worse comes to worse with you just lock out 6th

[Royce]

well i was just thinkin about doin it to take some of the strain off of my trans and get a little better of the line reponse

[RedBowTies88]

eh...its not really gonna make that big of a difference....torque output to the trans isnt gonna change long as the same weight and tires stay on the truck the stress on the trans will be the same for a given throttle amount....you'll just get slightly quicker acceleration with the higher gears

[YoKev]

well i was just thinkin about doin it to take some of the strain off of my trans and get a little better of the line reponse
I've talked to what I consider 'knowledgable' people on the subject, and the consensus seems to be that with 37's and larger, it's a real good idea to re-gear. As someone else wrote, you're simply trying to get back to the stock F.D ratio. Your fuel mileage will increase, and you'll take a lot of strain off your driveline. If it's in your budget, my opinion is it's a no-brainer.
Just make sure you do both diffs.

[Royce]

yeah thats what i been thinkin but have also heard its not gunna be a big difference so why put so much into it for such lil help