hi all, at the risk of being already covered..... I have a '51 F1 with reverse eye mono leafs on the front I-beam axle. Bought these from a reputable F100 supplier at one of the ford F100 truck shows. They lowered the front just like I want. For the rear leafs, a different F100 supplier at another F100 truck show told me to remove every other leaf in the rear to get the truck lowered. That got the truck down in the rear and now the stance is good!. But....the front mono-leafs are terribly stiff and I have a noticeable axle wrap in the rear even with the feeble but faithful flathead V8.
I want to replace both the front and rear with new multi-leaf lowering leaf springs and I would like to hear from you guys on this. I have been away from the trucking scene and shows for a while now and not sure what all is available anymore. Which suppliers are suggested, if you have changed out your springs, what are your opinions on your drop and the ride quality?
I am old school...I want to keep the leafs and steering the way it came from the factory...well...almost the same, just lower!.

 

Can't help you on the front as I installed a CPP IFS(2" drop spindles) on my 51 but the rear is a TCI Parabolic leaf spring kit that only required removing the rivets on the spring perch mounts to remove and drilling 4 other holes, I did have an issue with their measurement for the upper shock bar mounting holes which I ended up drilling an inch and a quarter farther forward because the shocks were not lined up with the lower mounting points.
Other than that the kit lowered the truck nicely and is not a harsh ride

https://totalcostinvolved.com/produc...ar-suspension/





This is why I had to move the bar forward 1-1/4" (pic from underneath looking up)

 

Posie makes replacement springs front and rear that lower (from stock height) 3”+/- with stock spindles. I installed them on the front (have four link in the rear) and they ride very nicely. The only problem I had was getting the original eye bolts out (rusted in; nuts too tight when installed). Posie (Speedway) also sent the longer u-bolts (out of stock on the short ones). There’s another member who installed them all the way around. I highly recommend.

 

I also used the Posie super slide springs in the rear with original original type shackles not the adjustable type. It lowered it about 3". They work good on my 54 F100

 

hi Ratty51F1, Nice patina...and stance! you would think the supplier would have picked up on the shock not aligning up after a few sales. I see the TCI kit you used are dual leaf

Dturk...were your Posie front springs multi-leaf or dual flex leaf? I can imagine the dual flex would be a little stiff, maybe not quite as much as the monoleaf.

Thanks guys...I never thought of these two companies ...only Eaton. I saw somewhere in the forums a member did not recommend Eaton ...but without an explanation why. Anyone use Eaton?

 

Dual leaf (on a 51 F1). Don’t seem that stiff, but that’s compared to the originals (less two springs, removed by previous owners). I also have a 302 up front if that makes a difference.

 

I chose the Posies spring set for my project, just not done yet. After doing the research, it seemed like the best option. The springs will have new bushings in the eyes so be sure to get a bushing and pin kit to rebuild the remaining hangers and shackles for a complete new suspension setup. Sloppy bushings, which allows spring side sway, is where a lot of wandering comes from while driving.
Here's a couple links that may be helpful.

POSIES Rods and Customs ? Super Slide Springs ? Street Rod Parts ? Hot Rod Parts ? Truck Parts ? Ford and Chevy Suspensions and Chassis Parts » POSIES Classic Truck Springs

POSIES Rods and Customs ? Super Slide Springs ? Street Rod Parts ? Hot Rod Parts ? Truck Parts ? Ford and Chevy Suspensions and Chassis Parts » 1952 Ford F100 Front Dual Flex Installation Article

 

My 49F1 has Posie Super Slide springs front & rear also.

 

What's your wheel and tire combo? Wheel offset? Rear end? I love how your truck sits and how the wheels fit.

 

Wheels are, US Wheel 52 series chrome smoothie. Front -15 x 6 x 5.5 w/ 3.75 backspacing Rear -15 x 8 x 5.5 w/ 4.25 backspacing ( from Summit Racing )
Tires are BF Goodrech Radial AT Front- 215/70R15 Rear- 275/60R15
Rear End is a 9" housing is from a 64 F100 with a 69 Mercury Cougar center section W/ TracLoc 3.25 gears.

 

52Merc...did you already install your springs? did you use dual flex in the front?

Looking at the Posies catalogue, the super-slide lowers the truck 2" in the front and 3" in the rear. They seem to recommend the dual flex over the super-slide for the front. They don't specify how much lower the dual flex is over stock, but I assume it is lower as it does not have the leaf thickness of the super-slide.

Sounds like you guys prefer the Posies. I wonder if they make their own or get them from a manufacturer? No comments on Eaton Detroit? They do seem to be more expensive.

 

Akaik, Posies makes their own. They have been in the street rod business for a really long time and have a good reputation. I liked what they had to offer, they had a name I recognized, and the price was reasonable. For less than a grand, even factoring the bushings and anything else I needed to complete the rebuild, I could have all new suspension with the look I wanted. I have the Dual-flex and Super slide combo waiting for their turn. They're not installed yet. Based on other's experience, I don't think I'll be disappointed. There's great info in the two links I attached above. My understanding is the Dual-flex fronts are an improvement from the Super slides, so I went with their recommendations. I'm not even sure if they make a Super slide front anymore for our applicaiton.

Eaton Detroit is an excellent choice if you were looking for stock springs. They make them from factory specs. I believe they also do custom orders, but you still have to know what you want, give them the information, then hope it comes out like you wanted. The Posies parts are a known quantity. There's lots of guys that have used them and shared their experience. My 2c.

 

Guy's, just want to add that I modified my rear spring hangers to achieve the rear stance on my F1. What I did was flip the rear hanger & moved the front hanger up about 1-1/2".
Posie's claim 2" front & 3" rear drop w/ super slide springs but that might not be the case. I wanted a little more drop in the rear so I modified the spring hangers. Not sure but I think I got the info from the H.A.M.B. website.

 

On the same subject and not to hijack the thread.........(I can start a new thread if I am butting in)
I'm sorry the picture is so big. Not sure how to get it to load in a smaller form.


My 54 has eight leafs on the rear axle. By removing one or more leafs, does that make the ride any smoother and less jerky or does it just lower the rear a bit?
How many and which ones should be removed? It looks like the three lowest leafs in the pack would be the easiest to remove. Would there be enough thread left on the
U bolts or would new bolts have to be installed?

 

rpaxton939....A well known f100 supplier told me to remove every other leaf...I had 10 leaves to start....I think there are now 5. Removing the leaves lowered it nicely and the result was a smooth ride. The load capacity is obviously reduced.... so I did add air bags for extra load capacity...they only have a couple psi in them to prevent total collapse of the bags and not enough pressure to raise the truck. When I hook a 16' trailer to it (yes I do haul a car once in a while), I bump the pressure up. However, the real drawback for me is a very noticeable axle wrap ...even without towing and with the flathead motor. If you are running a later V8 with more torque than the flatty, I think removing some longer leaves might leave you with axle wrap as well. You might be ok with just the bottom leaves removed. It should lower it by the thickness of the leaves removes. looks like you have enough threads left on the U-bolt you might can test it easily.
I worked my truck hard before restoring it....i had several cracked and bent leaves in the rear....I had to replace them.

52 Merc..... Another well known supplier sold me on the front reverse eye mono-leaf springs....said it is a big improvement in ride and handling. I think his definition of improvement was the fact it had no leaves to slide, create friction, noise, etc. Plus they were so stiff, they dont lean in a curve...I think that was his definition of handling. It does make for a harsh ride. (Note: I did see somewhere the monoleaf worked better with a bigblock?)
Posies does claim their dual flex is an improvement, I just wonder if "their improvement" is the same definition. But its got to be better than the monoleaf !

moejr....do the reversed hangers get in the way of the bed?