All the more reason not to make it worse than needed.

 

ya. not to mention larger tires + stock gears = unhappy transmission. whether its an auto or manual, it isn't good for it. once you drive a rig thats geared up, you can't ever go back.

 

IDK, I think people make more out of regearing than need be.
Personally I don't know anyone who has regeared to run 235/85/16, and certainly not for 245/75/16. None of their transmissions have blown up. I know a LOT of guys running 33" tires and none of their transmissions have blown up either. In these trucks the trans is about the last thing to go. The engine is far more prone to failing.

The cost involved really just isn't worth the results. You're talking about a good amount of work and a lot of expense for very marginal "performance" gains. If you're going to open up your diffs and pay the expense to regear you might as well do it for more gains than a 235/85 or a 245/75. Gears pretty much cost the same whether its a 3.54 or a 4.71. So if you INSIST on regearing you might as well get the most out of your money. Run a 33" tire and regear to 4.11(4.12) and throw a locker in there.
I urge you to run the gear calculator here with different tire gear combinations and see what effects each has. http://www.ashcroft-transmissions.co...atio_calc.html
Here's some commonly available gears. Coil Sprung - Diff Gearing


Of course its your truck and you can do whatever you want. You just have to take people's advice with a grain of salt and consider their opinions vs their actual experience.

 

I would agree regearing for anything less than a 33" tire is not needed. At 33" you'll start to notice the difference a lot more. I'm currently running 315/75's (35ish tire) on stock gears and it is definitely a dog. It's also a pain because that's roughly 16% above stock and since the Torque converter does not lock up until ~50mph I have to be doing around 60 before it locks up. Which does not happen often.

This winter I'll probably bite the bullet and get some 4.7x gears put in because the lack of power is really starting to bug me.

 

Dang, that's a lot for stock gears!
I used to run 265/75/16 on stock gears. Now I run 315/75/16 on 4.12 gears.
the 315/75 on 4.12 is closer to stock gears/stock tires than the 265/75 on 3.54 gears was, so that's good enough for me. Lock up is still around 50-52mph.

 

Yeah I know it's pretty bad. But I've been slowly drying to build the truck back up since I got it back last year. It used to have 4.11 gears but those where pulled by one of the owners between when I sold it and when I bought it back. I got a smoking deal on a Detroit and TT last year but they were on stock gears so I just threw them in for the time being. But I think once I save up my lunch money this fall I'll spring for some new diffs.

I did the math on all the different gears. The 4.11's are close to stock (+3%) but this is my trail truck and hardly sees road use so I'm going lower than stock. The 4.75's should put me at -12%. Which I think will be just about right for what I do.

 

Right on. I have to drive pretty much anywhere I wheel. 3-4 hours each way is about average so I didn't want too tall of gears. Plus I got my front and rear 4.12 R&P's for about $250 shipped so that influenced my decision.
Your truck looks great BTW.

 

Thanks,

I used to do the same thing. But I'm just getting too old to worry about if the truck is going to make it home on Sunday. Plus I get the same or better mileage towing as I do driving. I averaged 12.1 mpg doing 70-75 on my 800 mile round trip to SAE.