how many leaf springs are supposed to be on a 78 f150 4x4 in the rear?? i got a 2 new sets of leaf springs, and they're supposedly off of a 77 150(?). the leaf springs that are currently on my truck have 6, and these "new" leaf springs have 5....was this extra leaf added by previous owner or was i told wrong and this 5 leaf pack off of a f100 or something?? thanks.

 

I have a 77 F150 4X4 and a 78 F150 2X4 and they both have 5 in them. My 74 F250 2X4 has 6. Hope this helps.

 

its prolly a overload spring, mine has one on it. i thought the po did a backwoods lift and added random leaves to it for bigger tires.

 

My '77 has 5 leaves, 4 look like regular leaves meaning thickness is constant. The bottom leafe is a progressive leafe, very thick in the center and tapers towards the ends. My '77's springs are 3" wide.

I once compared them and the frame to my BIL's '77 F-250, rear springs were exactly the same .... but his daddy (my FIL) had added a set of overloads with home made slapper perches above them, he used some old narrow leaves for those.

I once had a trailer that was made from a wrecked '76 F-100 / 150 2WD PU that had a 3.00 rear gear in the 9" rear. It had narrower 2-1/2" wide leaves, forget how many. I added several leaves from an old Dodge to the stack and used longer U bolts and center bolt. Removed the pinion gear and put a plate over the hole and used it to haul some heavy loads.

 

well my leafs are 3" wide. both sets of them are. the set thats on my truck currently, looks to me like the leaf under the main leaf (the leaf with the eyes) is the added leaf. longer than the other ones on the "new" packs. im wondering if i should tear them apart and add that longer AAL to my new packs or not...how much is one leaf going to help?

 

my 74 F-100 has 9 under each side...

 

Depends on where you put it?

If a longer leaf and you place it below the shorter leaves, it acts more like a short leaf and it starts working only after some sagging, after the longer leaves above have already arched some.

If put up between the other leaves where it's ends are in contact with the next longer leafe above ity so it starts working immediately, it makes trhe whole pack stiffer earlier.

 

Interesting... I've been wondering if i could use spring count to determine what the ones under my bronco are from.

I had to go look at my trucks. If going by leaf count to determine weight ratting; my 76 f150 2x4 has 5 leaves per pack, but the 78 250 4x4 has 5... The 150 could be sprung heavy because its a trailer special (10,000 lbs tow rating has to have more spring than a stock 150 IMO)

The 250 is a camper special though, soposed to be a half step between 3/4 and one ton trucks acording to the ratting on it.. 3/4 sprung, but a D60 rear for the heavier rating apparently.

Regaurdless of that being true or not, the kicker is I have 6 leaves on the packs under the 78 bronco... from the previous owner, I know that they're out of a high boy, a pre 77 4x4 of some sort... if 5 is a 250, then is 6 a 350/1 ton?

Then again, compared to other combos in this thread, seems it isn't a linear scale...
Hmm. Interesting, none the less.

I'd need to check widths I think to tell much on mine. I am assuming that a wider spring pack with the same count and thickness of individual leaves can be a heavier ratting...

Hmm.

 

Interesting... I've been wondering if i could use spring count to determine what the ones under my bronco are from.

I had to go look at my trucks. If going by leaf count to determine weight ratting; my 76 f150 2x4 has 5 leaves per pack, but the 78 250 4x4 has 5... The 150 could be sprung heavy because its a trailer special (10,000 lbs tow rating has to have more spring than a stock 150 IMO)

The 250 is a camper special though, soposed to be a half step between 3/4 and one ton trucks acording to the ratting on it.. 3/4 sprung, but a D60 rear for the heavier rating apparently.

Regaurdless of that being true or not, the kicker is I have 6 leaves on the packs under the 78 bronco... from the previous owner, I know that they're out of a high boy, a pre 77 4x4 of some sort... if 5 is a 250, then is 6 a 350/1 ton?

Then again, compared to other combos in this thread, seems it isn't a linear scale...
Hmm. Interesting, none the less.

I'd need to check widths I think to tell much on mine. I am assuming that a wider spring pack with the same count and thickness of individual leaves can be a heavier ratting...

Hmm.

 

yea, so maybe you can't determine what springs came off what trucks with P.O. and what not. i'm probably going to leave the original 5 in the pack. doing the shackle flip with a stiff spring pack doesnt make sense haha