3.73 and 4.10 gearing Q&A

CMCx2012 · Jun 15, 2015

I went ahead and created this thread to kick-off the questions and keep everything to a definitive Q&A rather than hijack other threads with random questions. I myself have a ton of questions on this issue, and I am sure there are others who want to know as well so let's hear from the subject matter experts!

(1) What gears (3.73 or 4.10) would you use and what are the overall reasons?
(2) What brand is recommended?
(3) What size is best if you are running 35's and why?
(4) Drivability issues in either gearing?
(5) Anything else worth noting...

Thanks for the help in advance! Please don't hesitate to make comparison and/or add your own personal .02.

sootie · Jun 15, 2015

i would only run ford gearsets. sunrise sells them for a good price.

CMCx2012 · Jun 15, 2015

Thanks man, I saw a couple of shady deals from no-name sets.

gfulton · Jun 15, 2015

The only thing I'm the least bit worried about is finding a reputable shop to set lash, etc.........

14ccd · Jun 15, 2015

Are you planning on a bigger tire in the future? What do you tow and how heavy is it? Do you carry any weight in the bed, if so how much? Are you looking for off the line performance or is this a cruiser? I ask these questions because you only want to do this once, so the more info I have the better I can answer your questions.

CMCx2012 · Jun 16, 2015

Gearing...

14ccd said:
Are you planning on a bigger tire in the future? No, just my 35's. Thought about 37's but I am not putting flares on the truck.What do you tow and how heavy is it? Empty almost 99%Do you carry any weight in the bed, if so how much? Are you looking for off the line performance or is this a cruiser? Both, to be perfectly honest, but I will take what I can get in that aspectI ask these questions because you only want to do this once, so the more info I have the better I can answer your questions.

Thanks for your help!

1st last59 · Jun 16, 2015

I have 3.73 on my Dually with a 4.5" lift and 35s. Works good. Truck weights 11k all the time and I pull an 18k 5th wheel from job to job. I think 4.10 would be to much.

UNBROKEN · Jun 16, 2015

I have stock 3:55's with my 35's and can't see any reason to change anything.

ChattyCathy · Jun 16, 2015

UNBROKEN said:
I have stock 3:55's with my 35's and can't see any reason to change anything.

Same here.

jcain · Jun 16, 2015

I have 3.31s w/ 35s and think it's great. The split from 5th to 6th is perfect. But this is all debatable because of speed limit variations all over the country.

StrokinDuty · Jun 16, 2015

I'm running stock 355 with 37s and although it pulls them fine, was curious about going taller also.

cousincleatus · Jun 17, 2015

3.73's on 37's tuned and deleted but plenty of power to tow . 4.10's I think would be hell on rear tires .

int:

torque beast · Jun 18, 2015

jcain said:
I have 3.31s w/ 35s and think it's great. The split from 5th to 6th is perfect. But this is all debatable because of speed limit variations all over the country.

I am the same set up. I am lifted 4.5" with Toyo MT 35" tires and can pull my tractor at 75 mph on the interstate with no issues. The low geared transmission helps a lot to get going and once moving there is plenty of hp. The only way I would gear down is if I was pulling heavy. You can actually hurt your 1/4 mile time by gearing too low

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TrickTruck · Jun 19, 2015

Also at 3.55 and 35"
No problem (other than sway) towing a big box grossing 25klbs

Pulled away from a toll booth in IL and slowly mashed the throttle. It was spinning the tires with 2500#s on the hitch

CMCx2012 · Jun 19, 2015

Clean-15 · Jun 19, 2015

Before I went to 37's you couldn't convince me that I'd be happy with my stock 3.55's. I've owned a few lifted trucks with oversized tires and put gears in all of them after switching to bigger tires. I figured I'd have to on this truck as well and was wrong. My current setup with a short 37 and 3.55's drives better than it did stock.

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CMCx2012 · Jun 26, 2015

So basically the 4.10's would scream at highway speeds or does that only apply to my old Mustang GT that had them, lol.

The consensus is that the 3.73 with 35's wont be more of a benefit over the factory 3.55 gearing, am I right?

TrickTruck · Jun 26, 2015

3.55s and 35s are stock
you can get 3.73 and 4.10 in the drw 350/450, but not in a srw 250/350

personally I have no complaints w/ my 3.55s and 35s

CMCx2012 · Jun 27, 2015

I know 3.55 are stock, but what I was asking is will I basically get nothing out of the 3.73 upgrade?

I won't be towing really, just gonna be a built truck that will see road duty 90% of its life...

djr4x4 · Jun 27, 2015

IMHO.. You will not see a significant change going from the 3.55 to a 3.73... If this is a non towing, pavement duty truck and your going to run 35's then spend your money else where rather then changing from a 3.55 to 3.73.. Not worth the coin for that change..