Changing rear end gears
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shane_th_ee
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Hold up a minute here. Apparently for 2021 Ford now offers the Max tow with the 3.73 without the eLSD. If true, it might be a lot simpler. Note that the rear springs and should also be replaced.
Deadman
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The ABS reluctors, PCM programming, front diff gear swap, etc still needs to be done.
JasonH
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It's only a 10% difference over the 3.31, and the transmission has 10 speeds to choose from. I would be more concerned about cooling.
Deadman
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A 10 speed transmission can't make up for the Mechanical Advantage of the 3.73 gears. Its still 10 forward gears pushing a tall gear set.
JasonH
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Sure it can. Just use a lower gear. Yes, you loose 10% advantage in each gear, but once you're moving it doesn't really matter because you have so many gears to choose from. Before 2018, the 4x2 and HD tow came with 3.31. It was still rated to tow 9,000 lbs.
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sjwhiteley
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All things being equal, yes. However, each gearing is designed for a specific mechanical torque capability. You can’t just drop to 9th and have the same mechanical advantage without additional torque applied to the 9th gearset.
I believe the 2017 had a 6 speed transmission?
Experiment with lego gears and you will see how easily you can break things.
All things being equal, yes. However, each gearing is designed for a specific mechanical torque capability. You can’t just drop to 9th and have the same mechanical advantage without additional torque applied to the 9th gearset.
I believe the 2017 had a 6 speed transmission?
Experiment with lego gears and you will see how easily you can break things.
Maybe if we are towing 100K. The 10 Speed and gears can easily make up the difference and handle the weight the Expy can tow safely. Look at all of us with oversized tires. We can’t tow now that we changed our final drive ratio? It’s about the engine and transmission cooling.
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Deadman
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mechanical advantage is still mechanical advantage. No matter how you swing it, its still an advantage.
Its no different than lifting a 100lbs next to your body vs 3 feet away at arms length.
Anything can compromise, like the transmission and such, but its always just that, a compromise......
Its no different than lifting a 100lbs next to your body vs 3 feet away at arms length.
Anything can compromise, like the transmission and such, but its always just that, a compromise......
i love this.
not needing to tow anything heavy, i also love my 3.31, it pulls like a freight train to me especially considering the sheer size of the expy. (that’s coming from a diesel touareg that is a monster + only beats the expy by reliability + handling like a porsche - because it literally is.)
honestly i would probably get myself in trouble with the “advantage” of the 3.73 paired with this engine. i already catch myself exceeding the speed limit just a little too much, without even realizing it, on my daily jaunts to school where my kid reminds me now that she is old enough / tall enough to read the speedo from the rear now. . :-/
i would absolutely not even dream of messing with the internal gears, too much of a PITA + variables, for not nearly enough “advantage” in return.
not needing to tow anything heavy, i also love my 3.31, it pulls like a freight train to me especially considering the sheer size of the expy. (that’s coming from a diesel touareg that is a monster + only beats the expy by reliability + handling like a porsche - because it literally is.)
honestly i would probably get myself in trouble with the “advantage” of the 3.73 paired with this engine. i already catch myself exceeding the speed limit just a little too much, without even realizing it, on my daily jaunts to school where my kid reminds me now that she is old enough / tall enough to read the speedo from the rear now. . :-/
i would absolutely not even dream of messing with the internal gears, too much of a PITA + variables, for not nearly enough “advantage” in return.
sjwhiteley
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R.e. Engine/cooling: Wouldn’t that imply that both the vehicles can tow the max rating? (Changing the radiator out to the HD one).
And you are correct that putting oversized tires will theoretically decrease your max rating (assuming the max rating is actually a max).
I am aware that there are numerous reports of the engine/cooling struggling at high loads: perhaps that’s truly the limiting factor and not the drivetrain.
shane_th_ee
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OT alert!
Mine, too. One of my favorite design elements of our old Jag was really deep set gauges. So only the driver could see the speedometer...
I'm in a similar situation; didn't do enough research before purchasing and will be towing right at max non HD towing. In my humble opinion, I would start with a radiator and cooling upgrade for more bang for your buck. Gears are gonna absolutely make a big difference, but you're talking a lot of dough to change it out. Just don't know if it'd be worth it; can't just change out the rear gears and call it done. I personally believe these are way underrated for towing from factory, and I think cooling will be the issue before anything. Saying that, I'm not the one who has to honor your warranty if you were to ever have problems. I'll soon be upgrading my radiator and adding another auxiliary transmission cooler just as a good buffer.
Here is something for you “ gotta have the 3:73’s to tow guys” to think about.
Looking at the 2021 build your own. The 3:73’s are not part of the HD tow package. But part of the eSLD package.
[emoji848]
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Looking at the 2021 build your own. The 3:73’s are not part of the HD tow package. But part of the eSLD package.
[emoji848]
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wakeboarder
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According to the 2021 towing guide, the 3.73 gears are required to get greater than 6300 lbs towing. Some 3.73’s only have 6,000 lbs of towing capacity.Here is something for you “ gotta have the 3:73’s to tow guys” to think about.
Looking at the 2021 build your own. The 3:73’s are not part of the HD tow package. But part of the eSLD package.
[emoji848]
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That’s the same chart for the 18-20’s as well. In 2021 they split the eSLD out of the package but this chart and brochure still reference the HD tow package including the eSLD. Window stickers are all over the place. Some have the HD tow and no charge for eSLD. Some have the tow and eSLD no charge and some charge for both. I would be pissed if I ordered the HD tow and later was told I need the 3:73’s. Or could just order the HD tow and save $1100.00 and get the eSLD for free. But if the 3:73’s are limited to 6K on some models it means the radiator is the bigger advantage like I have been saying all along.
Check out another great example of how easy Ford makes it to shop.
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