St Gearing

[ARC]

Just an idea but has anyone switched out the 3.58 gears for a taller gear.

Just wondering because it has a 10spd trans wouldn't it be able to handle a taller gear for faster acceleration.

 

[UNBROKEN]

A taller gear will give you better top speed. Shorter gears will give you better acceleration but also up the rpm you turn on the highway. I haven’t seen anyone change them in an ST but there’s no reason you can’t as long as you can find front and rear sets.

 

[2020FordRaptor]

It is expensive to change out diffs and I wouldn’t see a reason to since people regularly dip into high 11s with just a tune and a couple bolt ons. It wouldn’t be worth the price.

 

[Suprawill1]

I would believe this whole drivetrain set is programmed for stock optimal performance. As soon as things start to be modified, your reinventing the engineering. The diff gearing is best suited for the transmission gearing ratios, which are custom programmed for the engine's hp and torque. As mentioned, if you want that 1st gear shorter, more hp will do that. If you make it too short, you won't be taking advantage of the engine's power band. The turbos rely on load which would be reduced on shorter gearing. In my opinion, with a formidable tune, a shorter 1st gear would just be a wheelspin inducer. I would leave it as is and have it take you further down the road before it hits 2nd.

 

[I Bleed Ford Blue]

It would be easier and cheaper to go with a shorter tire, that will give you the same effect as changing gears.

 

[UNBROKEN]

It would be easier and cheaper to go with a shorter tire, that will give you the same effect as changing gears.

At some point you’ll need to revisit your shift points too.

 

[Lightning Struck]

Keep in mind the entire rear diff would have to be replaced, as the ring gear is welded to it.

 

[TMac]

I doubt trading the 3.58 for say a 3.73 is going to make any appreciable gains. It's not just about the final drive ratio, it's all about the ratios in each gear of the transmission. As such, the ST has a very good ratio set- see this post here. FIrst gear could be a bit higher along with second gear could be a bit higher which would result in only a single shift to 60 or so, which would help 0-60 times. Other than that, it's pretty well matched for performance.

 

[I Bleed Ford Blue]

Keep in mind the entire rear diff would have to be replaced, as the ring gear is welded to it.

No, they are machined as 1 piece.

 

[I Bleed Ford Blue]

Also, since the front axle assembly is a ford design, there is no aftermarket support and probably never will be so you're stuck with one of the few ford ratios available.

 

[Svtguy]

Just an idea but has anyone switched out the 3.58 gears for a taller gear.

Just wondering because it has a 10spd trans wouldn't it be able to handle a taller gear for faster acceleration.

Having a numerically higher ratio is and was important for 4 & 5 speed NA cars and any truck with larger than stock tires, but with a 10 speed auto and turbos every upshift shift results in the engine operating at or near peak TQ negating most of the benefits of a higher gear ratio.

With an 4WD Explorer you would also need to swap both front and rear differentials further driving down any real performance value.

On the plus side I believe that the ST’s 3.58:1 ratio is the most aggressive out of the explorer line up.

 

[I Bleed Ford Blue]

The hybrid EX gets 3.73's