Gear Change....

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Jul 31, 2010 | 12:21 PM

sambandit03

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From: Castle Rock, CO

Gear Change....

What do you guys suggest? I have 35s on the truck now, but will go with 37s once these wear out. I am thinkin 4.56 or 4.88. Just need to regain some of that power back and get some help when towing. I have 3.73s right now.

Jul 31, 2010 | 12:39 PM

Toreador_Diesel

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From: Houston, Texas

4.30=3.73 with 37s
4.56=closer to 4.30 with 37s (4.88 is a little overkill)

Jul 31, 2010 | 04:42 PM

TYZ78F150

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From: Stafford, VA

Quote:

Originally Posted by Toreador_Diesel

4.30=3.73 with 37s
4.56=closer to 4.30 with 37s (4.88 is a little overkill)

What formula did you use? I've seen it before, but can't remember where.

Jul 31, 2010 | 05:05 PM

gr8scott72

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From: Summit, MS

Quote:

Originally Posted by Toreador_Diesel

4.30=3.73 with 37s
4.56=closer to 4.30 with 37s (4.88 is a little overkill)

It's a V10, it's not overkill. Might even consider 5.12s

Jul 31, 2010 | 07:55 PM

Toreador_Diesel

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From: Houston, Texas

Quote:

Originally Posted by TYZ78F150

What formula did you use? I've seen it before, but can't remember where.

There is a formula, but this comes from personal experience and a very expensive lesson learned...

(new tire size/old tire size)xcurrent gear ratio= New ratio

In his case:

(37/31.6)x3.73= 4.36 or 4.30 gears

(37/31.6)x4.30= 5.03 or 4.88 or 5.12 gears

So I guess I was wrong about 4.88s, if he plans on towing and spends most of his time around town, 4.88s or 5.13 gears would be best. However if it's going to be mostly freeways, 4.30 gears fit the bill better.

Jul 31, 2010 | 10:26 PM

X_Hemi_Guy

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From: Florida

IF (big if)...sambandit is going to tow...he wants to get the final drive as close to 4.30's as possible with the V10...there is a 'calculator' at the top of the forums under the articles/specs pulldown that can work thru the tire size, etc...

I think from memory that would mean 4.88's as a minimum for 37" tires...

For some reason my computer tonight won't let me accesss the 'calculator' section of that pulldown...but you can easily (unlike me) go to the calculator section and crunch the numbers yourself.

TOWING wise...the V10 LOVES 4.30's as a FINAL drive ratio...but tire size is a critical piece of that equation.

Overall the V10 non-towing is fine with 3.73's as a FINAL drive for non-towing.

I'd suggest also a tune from Mike at 5-Star for both towing and non...he is a great person to work with for custom tunes...give him a call once you get the proper gears in your Ex!

Good luck,
joe.

Aug 1, 2010 | 10:08 AM

sambandit03

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From: Castle Rock, CO

I appreciate all the info guys. It's mostly for around town, but I do tow a little, and might a little more as time goes by. It's just pretty gutless here at a mile high, especially with the 35s, and will be even worse with the 37s. So, not really worried about 2000 mile freeway trips as I dont ever really see using this vehicle for that, its mostly a work truck for me. Defifnitely a tune is in order too, I agree. Not only to correct the speedo for the tire and gear change, but to try to squeeze some more ponies outta this thing!