gears
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gears
sorry if this has been covered, which im sure it probably has but for some reason i keep getting the message that search has been disabled. anyways, i have a 1984 f250 2WD 4.9L. i was wondering since my truck is geared so low, what can i do to get some more out of it. i dont even use the granny gear as i dont use this truck to pull houses down or two M1 Abrams around. basically what i want to know is, how do i know what type of rear end do i have? what is a dana 44, 60, etc. and can i change out the gears in the diff to get more out of my truck. and again, sorry about not searching but i cant. i think maybe becuase i havent posted here very often. thanks in advance for any links or help.
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It will tell you in the book. You have a code on the side of your door, and then you reference that in one of the books that come with your truck. I think my code was 15, but I remember that I have the 3.50 axle ratio.
BTW, I also have the 4-speed with the army tank pulling first gear, lol.
BTW, I also have the 4-speed with the army tank pulling first gear, lol.
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From: Virginia
Different years used different types of rearends. So I will not attempt to guess what a 84 had in it, but if the fill plug for the rear is in the rear cover, then you have a Dana rear. If the fill plug is in on the front driver's side of the rear, then that is a Ford Sterling rear.
If you have these hub looking things sticking out of the center of the rear wheels, then you have what they call a "full floating" rearend. This is the normal 3/4 ton rear, and the hub is actually the rear axle. You can pull the rear axle out with the wheel still on the truck.
They made a light duty semi-floating rear axle for some f250's. This will have the 8 lug axles, but will not have the hub sticking out the center of the rear wheel.
Dana had number designations for their rearends. Some of the old Broncos had a small dana 30. Most half ton axles on the front of the chevies and Fords are Dana 44's. An even bigger axle is the Dana 60, and the very large trucks can have a Dana 80. If your rearend turns out to be a Dana, then it's probably a 60. Look for a tag under one of the bolts, and it will tell you axle ratio.
If you have these hub looking things sticking out of the center of the rear wheels, then you have what they call a "full floating" rearend. This is the normal 3/4 ton rear, and the hub is actually the rear axle. You can pull the rear axle out with the wheel still on the truck.
They made a light duty semi-floating rear axle for some f250's. This will have the 8 lug axles, but will not have the hub sticking out the center of the rear wheel.
Dana had number designations for their rearends. Some of the old Broncos had a small dana 30. Most half ton axles on the front of the chevies and Fords are Dana 44's. An even bigger axle is the Dana 60, and the very large trucks can have a Dana 80. If your rearend turns out to be a Dana, then it's probably a 60. Look for a tag under one of the bolts, and it will tell you axle ratio.
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turns out, according to the tag on my door, i have axle code 23 which is a 3.54 gear ratio. from what i understand, if i go with a lower gear ratio, i will gain in top end speed but sacrifice acceleration. please feel free to correct me if im wrong. so, if i were to find a gear set to swap in that was say in the 2.6 or so neighborhood, what kind of gains would i really see? i really want to make this truck more usefull for highway driving as i plan on taking it back to ohio with me when i move this coming summer. also, on an unrelated note, i have started the "$50 dollar paint job." so far so good. were going places with this truck...
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From: Hampstead, NC
if you went with a gear in the 2.6:1 range you would see lower rpms at high way speeds once you got there. The top end would be "faster" at a certain rpm in high gear but pullin out from a light and getting up to speed would take longer than it does now. A friend had a F-150 with the 4.9L and a 5 spd with a 3.08:1 rear gear. It did good as far as gas mileage went, which is what you are looking for from the sound of it.
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after doing a quick internet search, i think something in the 3:1 ratio is much more realistic. i just threw the 2.6 out there trying to get some numbers. i have found quite a few places i can get in the 3 neighborhood for relatively cheap. what im looking at is maybe a 4bbl with the offy intake, the 3:1 gears, and i guess my last question is would i get any farther by finding a 5 speed tranny or a 4 speed with overdrive?
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From: Hampstead, NC
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it has a 4 speed manual, no OD. 1st gear might as well not even be there when driving on a daily basis.
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From: Hampstead, NC
Thats how mine is with a 5 spd and 4.10:1. My over drive is .75:1 as best I know. If you run the numbers. of direct 1:1 should be 4th gear and your rear vs. .75 for OD and your rear vs. direct and a steeper rear gear. you should be able to get an idea of which one will help more. but as far as swappin a trans goes, its prob gonna be cheaper and faster to do a ring and pinion. Im not sure fo what 5 spd trans you could swap into your truck.
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From: Campbell River, B.C.
My diesel truck was built with 4.10 gears. After swapping to 3.08s, I was supprised by how well it drove after the swap. The only time I noticed a loss of power was under 10 mph, instead of snapping my head back, it felt like a more gradual accelleration. But for running empty, no real change, it just upshifts later on.
I suspect if you were to make use of your 1st gear, you will get satisfactory performance off the line.
I suspect if you were to make use of your 1st gear, you will get satisfactory performance off the line.
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3.08 may not be enough if you have the 4-speed with low/bulldog.
I have a 3.50 rear end with the 4-speed with bulldog (no overdrive). If I wanted to really make some decent gas mileage, I'd go with a 2.73 or around that area. These transmissions are geared very low.
I have a 3.50 rear end with the 4-speed with bulldog (no overdrive). If I wanted to really make some decent gas mileage, I'd go with a 2.73 or around that area. These transmissions are geared very low.
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upon closer inspection, and with the advice provided by Franklin2, i have the fill port located on the rear of the cover and it also has a big 30 stamped on top of it. am i correct to believe now that i have a dana 30 rear axle? if this is the case, should i upgrade the whole axle or still just change out gears?
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From: Campbell River, B.C.
I highly doubt you have a dana 30 under there, its probably a ford 10.25" or dana 60",
Is there an ID tag attached to one of the rear cover bolts?
If you can post a pic, chances are it can be identified, although the gear ratio will still have to be decoded.
Is there an ID tag attached to one of the rear cover bolts?
If you can post a pic, chances are it can be identified, although the gear ratio will still have to be decoded.