Re-gear 14B FF from 4.10 to....?

[454cid]

I wonder if those lower ratios, are something from the Squarebody era or maybe something that was only available for fleet orders.

 

[GoToGuy]

It's a choice many who plan on towing heavy loads make . Think of construction or ranchers, farmers . Whether it's skip loaders, skid steer. Or a trailer full of beef or horses. And the moving heavy tractors, supplies. The One I ordered for the family ranch had the 5.13 (?). I moved two John deer 4000 series tractors and fuel bowsers. And other equipment. The neighbor bought one similar as he had Perchron draft horses. They can weigh up to or more 2000 lbs. In our case choice it's about moving the weight with more leverage. Not top end.
Have you considered where your horsepower and torque falls within your cruise speed rpm choice? Do you want to cruise at peak torque? Or a fuel efficient rpm? In this it might be you have target point , then move the numbers around get you answer. Similar to going backwards through a graph to find the uncorrected start number. Good hunting!

 

[DDTurbo]

1993 C3500 dually, 7.4, NV4500, 4.10 14B FF, 225/75/16 tires about 29.3" tall.

On the roads in Mexico folks are driving around 80MPH which has the truck turning 2800ish (2745 RPM according to gear calcs) for extended periods.

Every 14B FF I've seen in these trucks is a 4.10 so if I wanted to change gears I'd be spending some bucks to do so, instead of just hunting boneyards looking for a unicorn.

3.73 would only drop about 250 RPM - from 2745 to 2498

3.42 would drop 455 RPM - from 2745 to 2290... which seems more worthwhile for cruising speed..

...but I wonder how it would impact the overall driveability of the truck? This being the early version of the NV4500, it's geared L-6.34, 1-3.44, 2-1.71, 3-1, OD-.73

*DISCLAIMER* since major project creep has already taken its toll on what I've intended to spend on the truck, the likelihood I will actually DO this is very, very low - just "getting it on the list" is unlikely, nevermind the $1K+ it could cost just in parts. But it's an interesting thought exercise, for me, anyway.

Richard

On my 1 ton trucks I favor 255/85-16 tires.
That tire helps lower the cruising rpm's.

 

[Caman96]

On my 1 ton trucks I favor 255/85-16 tires.
That tire helps lower the cruising rpm's.

Nice tires, but Richard has already stated his truck is dropped.

You must be registered for see images attach

 

[454cid]

Nice tires, but Richard has already stated his truck is dropped.

You must be registered for see images attach

Hey where did you find that tire calculator? I've been using an ancient calculator for years and I'd like to find a better one.

Tire size calculator

 

[Caman96]

Hey where did you find that tire calculator? I've been using an ancient calculator for years and I'd like to find a better one.

Tire size calculator

225/75-R16 vs 255/85-R16 Tire Comparison - Tire Size Calculator | Tacoma World

255/85-R16 tires are 3.78 inches (96 mm) larger in diameter than 225/75-R16 tires and the speedometer difference is 11.4%

www.tacomaworld.com

 

[454cid]

225/75-R16 vs 255/85-R16 Tire Comparison - Tire Size Calculator | Tacoma World

255/85-R16 tires are 3.78 inches (96 mm) larger in diameter than 225/75-R16 tires and the speedometer difference is 11.4%

www.tacomaworld.com

Thank you, it's now bookmarked.

 

[pressureangle]

1993 C3500 dually, 7.4, NV4500, 4.10 14B FF, 225/75/16 tires about 29.3" tall.

On the roads in Mexico folks are driving around 80MPH which has the truck turning 2800ish (2745 RPM according to gear calcs) for extended periods.

Every 14B FF I've seen in these trucks is a 4.10 so if I wanted to change gears I'd be spending some bucks to do so, instead of just hunting boneyards looking for a unicorn.

3.73 would only drop about 250 RPM - from 2745 to 2498

3.42 would drop 455 RPM - from 2745 to 2290... which seems more worthwhile for cruising speed..

...but I wonder how it would impact the overall driveability of the truck? This being the early version of the NV4500, it's geared L-6.34, 1-3.44, 2-1.71, 3-1, OD-.73

*DISCLAIMER* since major project creep has already taken its toll on what I've intended to spend on the truck, the likelihood I will actually DO this is very, very low - just "getting it on the list" is unlikely, nevermind the $1K+ it could cost just in parts. But it's an interesting thought exercise, for me, anyway.

Richard

Since it's a thought exercise, I'll toss in the idea of a Gear Vendors overdrive, especially since it's 2WD. We did the same in our '96 Dodge Cummins 3500, for fuel economy empty and to be able to tow heavy at speed by using the GV and the factory overdrive off. I think they're about $3k new now but indestructable, and for your truck you might find a good used one under a motorhome in the junkyard.

 

[Roostius_Maximus]

Not sure I’ve seen a taller than 4:10 after the ‘91 body. I know the 3:42’s were available from factory in ‘74 lol, I’ve got a 454/th400 truck with them.

 

[someotherguy]

Thank you, it's now bookmarked.

I've been using the one on Discount Tire's site. https://www.discounttire.com/learn/tire-size-calculator

Since it's a thought exercise, I'll toss in the idea of a Gear Vendors overdrive, especially since it's 2WD. We did the same in our '96 Dodge Cummins 3500, for fuel economy empty and to be able to tow heavy at speed by using the GV and the factory overdrive off. I think they're about $3k new now but indestructable, and for your truck you might find a good used one under a motorhome in the junkyard.

GV is $4K+ w/tax and shipping and they do seem like a nice option, just expensive as hell. Not sure I'd find a used one easily considering my application of NV4500 instead of the TH400 or 4L80E you'd find on a coach in the boneyard - so while I might save money on the unit itself, then I gotta get the adapter housing, etc.

It's an interesting option but very unlikely one I'd spend the bucks on.

Also interesting - did you know? They recommend you change the oil in the GV unit every 5K miles. They suggest two choices for oil, one of them being the GM 12346190 synthetic that is used in the NV4500 and is expensive, and afaik at this point, discontinued / superseded by something else. So you'd be changing GV oil on roughly an engine oil schedule. I wonder how many used units out there in service had regular oil changes?

Richard