Ford 6.0 gear recommendation for 38s

[Hunter44]

2006 6.0 bulletproofed, Innovative Diesel Xtreme X tune, stock trans. With 38s what do y'all recommend? I don't tow or anything but cruise the street. Couple knowledgeable guys told me 3.73's would kill my transmission with that size tire.

 

[jeepinmatt]

Stock tires are about 34". I'm sure you've also read that, in general, a hot tune will kill your transmission. Assuming you have 3.73 gears stock, the size difference from 34" to 38" is 12%, so mathematically you'd need 4.17 gears. Since that doesn't exist, and you're trying to save the transmission, you'd want 4.56's (I don't think they make ~4.3 gears for SD axles).

 

[CasterTroy]

 

[Hunter44]

4.88 would give my truck a little more ass?

 

[Ron]

on the bottom end, yes.
Would limit your top end potentially.

You dont mention, but I assume it is a stock auto.
Don't know what your stock gears are either though...

 

[Croatan_Kid]

It says stock auto in the original post, actually. Stock gears are 3.73. The trans tune that's with that Xtreme X tune locks the converter in every gear but first, so that's worth mentioning.

I told you 4.56 gears probably 5 time already too.

 

[Ron]

It says stock auto in the original post, actually. Stock gears are 3.73. The trans tune that's with that Xtreme X tune locks the converter in every gear but first, so that's worth mentioning.

I told you 4.56 gears probably 5 time already too.

It's says stock Trans, not stock auto....

 

[obullfish]

Probably won't be stock for much longer running 38's.

 

[jeepinmatt]

It's says stock Trans, not stock auto....

Everybody knows anyone who calls it a "trans" is referring to an auto, and a "tranny" is a manual or a transvestite.

 

[Loganwayne]

Probably won't be stock for much longer running 38's.

Mine didn't last but a couple years with 35s towing the jeep everywhere like I was about to rob someone

Sent from my XT1254 using Tapatalk

 

[Jody Treadway]

I'd go 4.56 unless you tow a good bit of weight frequently then I would consider even 4.88 gearing.

 

[Croatan_Kid]

It's says stock Trans, not stock auto....

If it were a manual, he would have probably mentioned a clutch somewhere and the worry of destroying a transmission also leans towards it being an automatic. Just saying.

 

[Ron]

If it were a manual, he would have probably mentioned a clutch somewhere and the worry of destroying a transmission also leans towards it being an automatic. Just saying.

Agree it leans, that's why I said I assume..but you know how that can work.

 

[GubNi]

2006 6.0 Diesel I don't tow or anything. What do y'all recommend?

I'd recommend to sell it and get a honda, lol.

Sorry, couldn't resist.