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Discussion Starter #21
so now i wonder, should i just go right to 4.56? or can i get away with 4.10 in the front and 4.11 in the back. i dont want to F another trans, plus when i get it built i dont wanna risk anything on a $6000 tranny..

problem is 4.56 all the way around looks like $1000 atm.
 

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4.11 would be perfectly fine.
 

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iirc you can be up to .03 off between front and rear and still be okay.
so a 4.10 will work with a 4.13(though i dont think anyone makes those for this axle?)
it would be stretching it, but it is "allowed" per say..4.10 and 4.11 is perfectly fine

just re-gear your current axles
 

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iirc you can be up to .03 off between front and rear and still be okay.
so a 4.10 will work with a 4.13(though i dont think anyone makes those for this axle?)
it would be stretching it, but it is "allowed" per say..4.10 and 4.11 is perfectly fine

just re-gear your current axles
4.10s and 4.11s are Basically the same thing. The 6.0 gas trucks are 4.11 front and 4.10 rear.

If i remember correctly if you count the teeth on the ring and pinion of the 11.5 3.73 gear set and figure out the ratio by dividing you end up with 3.724 or something like that.
 

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Discussion Starter #25
Sweet. Gonna order those and the conversion yoke and u jints for the d60 up front. Should be in 4wd by next weekrnd
 

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If you're going to do 40's. Might as well do 4.56's and 40's at the same time. Instead of spending money on 4.11's now then switching to 4.56's later. If you don't have money to upgrade everything right now. Just don't wheel until you can regear. You could even run 4.88's with 40's.

You didn't realize you had two different ratios of gears?
 

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Discussion Starter #27
Im nowhere near 40s yet. I only need the 410s in the back so I figure fuckit spend a few hundred. Cause im gonna build up the engine more build the trans swap the lift then get 40s and new rims.
 

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4.10 will yield worse mileage than the 3.73s
Not with 4.10's on 38's it will help milage, take load off the drivetrain to make those tires and the trucks weight to get it rolling and driving. If you do 4.10s with 35's it'll put you back close to stock ratio
 

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Im running 4.56 on 38x13.50-24 on 24x14's and 3" spacers. On the hwy at 70mph Im getting 17.5 mpg.
 

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So if I'm running 3.73's on 325/65r18's, then i should def switch up to 4.10's? It will increase fuel mileage but decrease top speed and acceleration correct? Or do I have that mixed up?
 

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I would consider 4.56's if possible, 4.10's are "passable" but th purpose behind gear reduction; is to have the engine rpm's in the ideal torque range whether you're cruising or offroad.
the lower gears will help with bigger tires, simply because you're engine would be ptting out optimal rpm's/torque to move the larger tires. Torque range=Less work for the engine=Better fuel economy, even if you are running higher rpms, you may still IMROVE Fuel economy because youre engine will be running the ideal amount power to the ground: it will by proxy improve fuel economy, because it is not pouring fuel into the engine to compensate for the lack of engine speed (which is bad for efficiency). I wouldnt expect any huge gains, but it wont be as bad as if you left the 3.73's.
 

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I would consider 4.56's if possible, 4.10's are "passable" but th purpose behind gear reduction; is to have the engine rpm's in the ideal torque range whether you're cruising or offroad.
the lower gears will help with bigger tires, simply because you're engine would be ptting out optimal rpm's/torque to move the larger tires. Torque range=Less work for the engine=Better fuel economy, even if you are running higher rpms, you may still IMROVE Fuel economy because youre engine will be running the ideal amount power to the ground: it will by proxy improve fuel economy, because it is not pouring fuel into the engine to compensate for the lack of engine speed (which is bad for efficiency). I wouldnt expect any huge gains, but it wont be as bad as if you left the 3.73's.
AGREED! Well Put! Dont be affraid to over gear! 4.10's would be a waste of time, energy, and money if you currently have 3.73's.
 

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If you haven't re-geared anything before, watch lots of youtube videos and make sure you want to take on the challenge. You should need a press (you can get a shop to help out usually), a gauge to check back lash, some patience, etc... Gears, install kit, gear paint (install kit should come with a little), lock tite (usually install kit comes with a little as well), etc...

You'll want to read up the instructions for the gears you are putting in it and verify the tolerances they are looking for to avoid humming or other issues.

Also you will need to do a 500 mile break in that will destroy the diff oil and you'll need to change the diff oil. I would start with a cheap diff oil and then put better diff oil in after the 500 mile break in. Don't get on the throttle hard for that first 500 miles though.

As for gear ratio, as stated you want to be as close to stock as possible. For 38" tires I would go with a 4.56 gear front and rear.

ATPTrucks.com sells Yukon, I'm sure our other vendors sell gears as well. I bought my last Yukon carrier from them for a Mustang.

Make sure the gears you get for the front are cut for the front as well.

While you are in there it may make sense to upgrade the carrier if you have any upgrades planned. (IE: Different limited slip, locker, etc...)
 

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To say that duramax trucks Never came with 4.10s i think is a little short sighted and im not confident thats an accurate statement, thought they are definitely super rare if they exist.
uhh no it isnt....because they didnt. :rolleyes:

GM has never made a single duramax with anything other than 3.73's. This is FACT.

and yes, thats an accurate statement.
 

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uhh no it isnt....because they didnt. :rolleyes:

GM has never made a single duramax with anything other than 3.73's. This is FACT.

and yes, thats an accurate statement.
WTF Ben. Are you going to make me disprove that?

Im nearly certain there are some early Dually Pickups and cab and chassis trucks floating around with 4.10s.
 

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WTF Ben. Are you going to make me disprove that?

Im nearly certain there are some early Dually Pickups and cab and chassis trucks floating around with 4.10s.
I think you will need to, I haven't ever seen one.
 

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I'll ask you this right now do you know what backlash and pinion depth are? If not I'm guessing you've never regeared anything and I wouldn't recommend doing it yourself. If you know someone that has done it have them help because if it isn't right your going to be doing it again especially with something your driving down the road everyday.
 

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I think you will need to, I haven't ever seen one.
Challenge accepted. Im adament about this because im pretty sure a dump truck i looked at buying some years back had a gt5 in the glovebox.
 

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