Regearing or aux overdrive

War Wagon

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So my brother and I have both just recently purchased F550's that are equipped with 4.88 gears and 6 speed manual transmissions. A 2006 and a 2010 both diesels. We spend a lot of miles with them traveling down the road to jobs and the 4.88 gears are way too low for highway driving. We both plan on doing something too change this. I think we want to get to about the equivalent of 3.73's as our interstate speed is 80. I'm not even sure 3.73's exist for the Dana super 60. Maybe an auxiliary gear box is something to look into. I figure someone on here knows more about this stuff than me.
 

Clb

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I will vote for a multi gear brownie all day long, but a 2 speed would be my next best.
I would want the ability to split gears and have the final in od.
if ya regear ya loose some towing grunt.
just my .02
 

FORDF250HDXLT

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swapping in a set of pickup gears defeat the purpose of owning the truck imo.it's built to haul and tow beyond that of a pickup.to make it more pickup like,ruins the truck as it would no longer be capable of its payload and tow ratings.

i contemplated re-gearing my f-super duty but then i thought why? it's made for making money.it can do what chip truck can do in two trips in just 1/half the time.so instead of getting it's 10 mpg like it does,it really only needs to get half of what chip truck does,which means 7 mpg would still be like working chip truck.that doesn't even account for the man hours in time saved by combining two trips into one.it could probably theoretically get half an mpg or so and still save me money so.

id recommend selling the truck you don't need and buy one that you do.
if your response will be: i do need it to haul/tow the weight,beyond the ratings of a pickup.just not all the time,down the hwy.then your left with only one choice.leaving it's gears so you don't ruin it's capabilities and get an aux od unit.
 

hce

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Depending on rear end you may be limited to 4.11 or 4.30. Looks like the front has more option change. Give Inland in Billings a call to find out what gearing options you have. Place of work runs a half dozen one tons with a service box, crane, compressor, welder, throw in mechanics tools and inventory of parts and the trucks are pushing 18000 lbs. There geared with 4.10 although with an auto, but not uncommon for one to cover 300 plus miles in a day getting to different jobs in NE MT. Never give a second thought if we need to pull a trailer with parts, skidster or forklift. Without trailer they will run 80 comfortably. Your are technically limited to the the truck speed limit though.
 

79jasper

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What are they? 6.0 and 6.4 psd? Or?
I would say a splitter.
Is that a zf6? Gear vendors is 3D0172A $4k each. Lol

Sent from my SAMSUNG-SM-G935A using Tapatalk
 

War Wagon

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I checked with Inland truck already and I'm told for the Dana super 60 front axle that the only other option is 4.30. One is a 6.0L and one is a 6.4L and both are running with a programmer. They both make plenty of power and I have no worries about ruining their capability. F450's/550's are nice because they have huge brakes, 19.5 wheels, and suspension that handles the load, not to mention carrying the load legally if the DOT stops you. The part about them that sucks is that they only have low factory gear options. Different users have different needs. My needs may be to go down the highway several hundred miles a day and I don't want to do it at 3000 rpm. I have driven many different ZF 6 speed equipped Fords and even paired with a 5.4L gas and 4.10 gears this transmission helps make it able to move a big load that it would struggle with if it were an auto. So, I really have no concerns of loosing capability. If anything these have a lack of capability in the fact that they are not even practical to drive at highway speed. This thread is just about options to achieve a better highway gear.

Clb - I do like the idea of the brownie box but I don't know much about them. What more info can you share about those or where is a good source on more info on those?
 

War Wagon

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It looks like a Spicer 5831 "Brownie box" might be a good option but I don't know much about them. I think this could be an option to have 2 overdrive gears. Anybody have or know of any good resources on these?
 

Clb

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Think of it as another gearbox after the final drive aka 5sp, 4sp, 3sp gearbox....a 2 speed would be direct, in first, od in 2nd.
The 3 speed is direct in second, under drive in first, overdrive in 3rd.
then a 4 speed will usually be a shift pattern like this....
keep track if ya can:confused:
start out from a stop...
brownie in 1st. 1-2-3-4-5 (5th gear), brownie into 2, then main box into 1st,then shift 2-3-4-5 (10th gear), brownie into 3rd, main into 1st, then shift 2-3-4-5 (15th gear) guess what happens next!

oh and when ya get to 20th and need to stop you go back down the ranges in reverse order.

still with me?;Sweet

then there is splitting gears..... for another time.

this is what the old tractors were like way back when, you may have heard an old timer state..."I dune plain fergot where I was" (in the gearbox) this was how shifting the brownie with your rt. hand on the brownie box and your left arm thru the steering wheel shifting the main came into fashion. ( also referred to by the new guys as "suicide jockies".

thats a crib notes version.

you wont find many 4 gears today.
look for a 3 sp.
 
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nelstomlinson

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I've got a '89 F-Superduty, 7.3L diesel, 2wd, with a ZF5 and a Dana 80 rear end, 5.13:1 gearing. It cruises comfortably at about 50 in overdrive. The old naturally aspirated IDI needs that gear down to handle the 12,000 pound gross weight on the hills, but it would be really nice to be able to hit 65 on the flats. I am really interested in hearing about any options for brownies, shift splitters or such.
 

towcat

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regear to 4.56's is the simplest.
being out there in BFE I'd think twice on a aux OD. I've killed my share over the years.
 

nelstomlinson

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regear to 4.56's is the simplest.
being out there in BFE I'd think twice on a aux OD. I've killed my share over the years.

I'm a little way out - the big city is 100 miles away. We do have a NAPA here just three miles from the house.

I'm not sure I'd want to go with an auxiliary OD. I've looked at Gear Vendor's offering, and been underwhelmed, though the price seems overwhelming for what you get. It just doesn't look heavy duty.

I had really hoped I could find a shift splitter for that Dana 80, but it looks as if there has never been such a thing. I used to have a '65 C-60 with a shift splitter, and it was great until I tried to split a shift on a cold morning and the rear end got stuck between gears.

I'll go through some of the junky yards in the neighborhood and see if I can find an old heavy truck with an old brownie. I've driven a two gear box rig many years ago, and wouldn't mind doing it again. It will be a project for a few years down the road, so I have time to dig around, find information and bits and pieces, and get everything lined up.
 

jbm6900

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I'm also in the hunt for a aux OD gearbox, for different reasons tho. I'd like to drop a 12v Cummins under the hood. Stock gears fine for local. Aux. OD be used runnin 2wd on highway. It's a rpm thing w/ Cummins.
Btw: Jus cause you have a splitter, does not mean you must split every gear. That's only for the heaviest of loads. And yes, I have driven a old naturally asperated Mack dumptrk w/ a 18sp Quadruplex. Miss a gear w/ that, & you might as well pull over & start all over again. Seperates the real drivers from the steer wheel holders real quicklike.
 
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