4 speed to 6 speed

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Old 02-19-2013, 01:16 AM
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Question 4 speed to 6 speed

I have a 4r70w in my truck. There is nothing wrong with it. But it seems it would be a great idea to find a more geared trans. that would help the gas mileage.

The big question i have is there a 6 speed ford trans. that will fit?? Its a 5.4 engine. I am also guessing that changing the gears in pumkin with 6 speed may be needed too???

One other question when you say a 4 speed in auto,,, thats a 3 speed with 4 being OD or is it different setup,,, like a 4 speed with a 5th speed being OD???
 
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Old 02-19-2013, 10:41 AM
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Anything can be made to fit, but the electronics involved with putting a 6 speed into your truck would make this a difficult and expensive swap. The 6 speed uses a separate computer where your 4 speed is controlled by the same computer that the engine management uses. I doubt you would see better gas mileage, 6th in the 6 speed is roughly the same ratio as 4th in your 4 speed. The only thing the 6 speed would do is give you more grunt off the line because 1st is deeper.

The cost of doing this will buy a LOT of gas, there will not be anything close to a payback over the rest of the life of your truck.

when you say a 4 speed in auto,,, thats a 3 speed with 4 being OD
Yup.
 
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Old 02-19-2013, 11:11 AM
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Originally Posted by glc
Anything can be made to fit, but the electronics involved with putting a 6 speed into your truck would make this a difficult and expensive swap. The 6 speed uses a separate computer where your 4 speed is controlled by the same computer that the engine management uses. I doubt you would see better gas mileage, 6th in the 6 speed is roughly the same ratio as 4th in your 4 speed. The only thing the 6 speed would do is give you more grunt off the line because 1st is deeper.

The cost of doing this will buy a LOT of gas, there will not be anything close to a payback over the rest of the life of your truck.



Yup.
Nicely stated.....
 
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Old 02-19-2013, 10:39 PM
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So whats the point of putting any 6 speed in any truck then,, now adays???

Assuming like you said 4th being the same in the end. From what i read 6 speed is great for towing,,, other then that its like **** on a boar. So theres no way to transplant one in even you if got the separate trans control box.

Was well aware of the cost thing being the white elephant in the room.

So why do they put 6 speeds in trucks now?? Hell dodge has a 8 speed,,, class leading as they put it.
 
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Old 02-20-2013, 12:35 AM
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Like glc said, the lower gears are better for towing and coming off the line. But besides that no massive noticeable gains in mileage.

And yes again like glc said, it's possible but there's no real point unless basically you just want to be able to say you have a 6-speed in your truck. For the cost it's just not really feasible.
 
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Old 02-21-2013, 12:20 AM
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A 6 speed (or 8 speed) will get slightly better EPA gas mileage, which is very important these days with the increasing CAFE requirements.
 
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Old 02-21-2013, 08:09 AM
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Originally Posted by K.R.newbie
One other question when you say a 4 speed in auto,,, thats a 3 speed with 4 being OD or is it different setup,,, like a 4 speed with a 5th speed being OD???
It's a four speed with fourth gear being an overdrive ratio.

For those of you that must call it a three speed with overdrive, why only single out overdrive as not being a gear? You really should call it a one speed direct drive with two underdrives (first and second gears) and one overdrive.

Many decades ago there were overdrive units that were attached to the rear of the transmission. Those were three speed transmissions with an overdrive. Modern transmissions are designed from the start as four (or five, or six, or seven, or eight...) speed transmissions. One or more of the gears are a ratio greater than 1:1.
 
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Old 02-24-2013, 11:28 PM
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So its all a BIG MASK for truck makers,,,,, our trucks get better gas mileage from the EPA with the 6 and 8 speed. They also toot their towing horn tooo.

Think they might get some ideas from otr trucks and put a manual 6 or 8 speed in a gas truck. They also pull alot weight too,, so not likely. Wow we are really at the feet of the auto makers.

Would think that if they are so gas sipping conscience,,, a manual gear box gets better gas saving then a auto. Can you imagine a ecoboost with a 6 speed manual.

Guess everyone should learn how to use a clutch in a vehicle.

MAKING SENSE WAS NEVER PART OF FEASIBLE!!!
 

Last edited by K.R.newbie; 02-24-2013 at 11:37 PM. Reason: ah shucks
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Old 02-24-2013, 11:32 PM
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i love manuals just for the fact on being able to controll better...
 
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Old 03-05-2013, 10:38 AM
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On the EPA drive cycle, a manual does NOT necessarily get better mileage than a computer-controlled automatic.
 


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