Getting new gears
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Joined: May 2007
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ManualF150:
Your posts look like they are regurgitated internet posts. As i can tell you have not a clue what you are talking about nor any true experience with gears on a rear differential.
Your posts look like they are regurgitated internet posts. As i can tell you have not a clue what you are talking about nor any true experience with gears on a rear differential.
Originally Posted by ManualF150
With 3.55's, it takes say 2 turns of the drive shaft to turn the wheels one complete rotation. With 4.10's, it will take say 4 turns of the drive shaft to turn the wheels one complete rotation.
- 3.55:1 is not 2:1
- 4.10:1 is not 4:1
- And the difference is only ~half a rotation.
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Joined: May 2004
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From: san diego
im originally from kansas city, im not too happy seeing my hometown represented as a ripoff people city, but that price is extreme unbelievable ripoff price, go egg their store or something... from what i know, a full install with master install kits for a 4x4 is about 900-1500, i would pay about 1100 for a shop known for excellent quality control and experience
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Originally Posted by ManualF150
What I mean by this is when you are driving along with a 5,000 lb load, and you meet a hill. Say a small one, just for grabs. When you are towing a load, before you hit that hill you will be in O/D or 4th gear in the AT at say 2,000 rpms. As soon as you hit that hill, the truck will sense that it needs to downshift into 3rd because it is sensing a greater load and more gas is being applied when you push down on the pedal and thus raising the rpms to say 2,500 rpms. That will normally occur with when you are running a lower gear ratio, like 3.55's. However, if you have 4.10's, your truck will be running in 4th gear or O/D at say 2,400 rpms. As you can see, you are already in the "correct" hp/torque band, thus your truck does not need to downshift when it meets the hill. When a transmission downshifts, it is trying to match the correct hp/torque band to the engine's load.
A
3.55:1
32" tires
4th gear at 2000rpms = ~77mph.
Going up hill, kick down to 3rd to maintain 77mph 2871rpm.
B
4.10:1
32" tires
77mph in relation to the 3.55
4th gear at 2300rpms = ~77mph.
Going up hill, kick down to 3rd to maintain 77mph 3316rpm.
Now a 5000# load on a slight hill, the truck will still downshift with the 4.10s, i dont even think the IMRCs are open under 2500rpm. Anything above 2500 is good as the stall on the tc is ~2500rpm anyway.
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Joined: May 2007
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From: Jupiter, Florida
Originally Posted by gcr235
i have a 2004 screw 4x4 with 3.55 gears. i am interested in possibly changing them to 4.10 to help with towing and i might want to go with 33" tires. anyway, i called a reputable ford place in kansas city to ask how much to change the front and rear to 4.10..........he said $4,700.00
wtf
wtf
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Joined: May 2006
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From: Mandeville, La
Originally Posted by ManualF150
...I don't know what the final drive ratio in O/D is on the 4R75 is when it is coupled with a 3.55 nor 4.10 rear end. So you might be right, or wrong... I don't know.