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Leaf spring upgrade ?

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Old Aug 22, 2019 | 09:34 PM
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Leaf spring upgrade ?

Ok I have a 74f100 looking to upgrade the rear springs. Will leaf springs from a 77 f250 be beneficial? Should I swap the axle out as well? Would I be advised to up grade the front coils also both 2wd

thanks in advance
 
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Old Aug 23, 2019 | 03:13 AM
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You can buy some replacement 1/2 ton F150 leaf springs that have a heaver weight rating. You could swap in some F250 ones, they will have a heaver weight rating and the truck will probably ride like a buck board.

As far as the axle you should have a 5 lug 9" with ether a small or big bearing set up. A 9" is a pretty tough axle in general. If you want to swap in an axle from a F250 (Dana 60) keep in mind that axle will have 8 lugs because it is a 3/4 ton axle.

What is the purpose of the upgrade, truck bottoms out when hauling a bed load of stuff, bottoms out when you hook a trailer to it? There are some bolt on options other than new leafs. Like air bag over loads or adding an "add-a leaf" (that light raise the rear up 1 to 1.5" though) and you can get that rough ride I mentioned earlier.
 
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Old Aug 23, 2019 | 05:10 AM
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Originally Posted by 77&79F250
You can buy some replacement 1/2 ton F150 leaf springs that have a heaver weight rating. You could swap in some F250 ones, they will have a heaver weight rating and the truck will probably ride like a buck board.

As far as the axle you should have a 5 lug 9" with ether a small or big bearing set up. A 9" is a pretty tough axle in general. If you want to swap in an axle from a F250 (Dana 60) keep in mind that axle will have 8 lugs because it is a 3/4 ton axle.

What is the purpose of the upgrade, truck bottoms out when hauling a bed load of stuff, bottoms out when you hook a trailer to it? There are some bolt on options other than new leafs. Like air bag over loads or adding an "add-a leaf" (that light raise the rear up 1 to 1.5" though) and you can get that rough ride I mentioned earlier.
Thanks for the reply...... the reason for the up grade is when towing a flat deck trailer with any kind of weight at all feels soft and as if the truck can hardly handle any kind of a load behind it. I’m not talking about a huge load I know it’s not a 3/4 ton or one ton. I’m talking about a load that a late model f150 could handle with ease like a load of 100 small Square bales of hay, a farmall h something along those lines as an example.
 
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Old Aug 23, 2019 | 07:02 AM
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Lol one thing for certain, you won't see a late model F150 doing farm work nearly 50 years from now. But your 74 still will be.

I personally would upgrade to 77.5- - 79 F250 rear leaves, spring hangers and dana 60 rear axle. Springs are a little wider and ride slightly better than the earlier stuff. Your current 9 inch is beefy, but it's nearly 50 years old and your asking it to do 3/4 ton farm work, which is not easy. You can still score a whole D60, springs, hangers and axles from a junkyard fairly cheap. If you are anywhere near northeast PA, I'll give you the name of a guy who has rows of them.
 
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Old Aug 23, 2019 | 07:37 AM
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Well 100 square bales at an estimated 60 to 80 lbs a piece for roughly 6000 to 8000 lb. Or a Farmall H est weight 3875 lb is no slouch weight to be towing and do not forget to add in the trailer weight itself back there. I am sure your 1/2 ton feels it. Look at the above chart, you might be over loading the truck in the 1st place.

Remember that putting a trailer back there and then load it , and that shifts the weight to the rear axle and lifts or lightens up the front end weight. Therefore you feel it in the front steering and front braking ability.

Are you loading the trailer properly? Like most of the weight over the trailer axles? You could invest in some rear F250 springs, a rear sway bar, quality rear shocks. Maybe some over loads leaf springs too? Do you at least have a trailer with elec brakes and a brake controller in your truck? Might help some.

Remember that the 74 F100 had a GVWR X (see above chart for your wheel base)_ versus when the 1975 F-150 was introduced; this truck was designed with a heavier GVWR (over 6,000 lb (2,722 kg)) and maximum payload. Good read here and some discussion before it turns in to a bla bla bla.
https://www.ford-trucks.com/forums/9...nt-models.html
 
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Old Aug 23, 2019 | 02:30 PM
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You are going to need more than springs to make your truck compare to a newer f150. Newer f150 have load capacities close if not exceeding the 60-70s f250 fords. They also have heavy sway bars, better brakes, and more horsepower.

That said some rear helper air springs should help and would be adjustable.

It all depends on what your needs are. Are you pulling some weight around town or driving 70 mph loaded for 8 hours?

 
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Old Aug 23, 2019 | 05:54 PM
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A lot of improvement can be had with a set of air helper springs(air bags). They really aren’t all that expensive and will be a lot quicker and easier install than replacing the rear half of your truck. Plus, as an added bonus, you will retain the car-like ride of the f100/f150 while upgrading to the towing capacity of a much larger truck. The newer half tons may have more power but lack in the weight carrying as well, just not as bad. If it were me, the air bags would be the alteration I would choose. I think you would find what you are looking for going that route. If it was a larger truck, that would be the best alternative as well. $.02
 
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Old Aug 23, 2019 | 09:07 PM
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Thanks for all the advice
 
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