Technical 1937 Ford pick up front suspension question

Hey all, kinda new here and working on a 37 ford pick up and was wondering if anyone could share experience on front end retro fits. I'd like to maintain the straight axle front suspension but was wondering if anyone has had any experience or input on converting to a 32' style drop axle with hairpins. I'm also building a 31 on 32 rails so I can see that the spring is directly above the axle on my 32 frame, looking at the 37 truck I can see that the leaf is forward of the axle which would require a relocation of the cross member. Any body have advice or recommendations as to what type of cross member 1- can be made to fit, 2- will lower me a little with the 4" drop axle i hope to use. I intend to run full fenders front and rear but love the low rod look. The plan is to either 4 link or ladder bar the rear. Any input would be appreciated and considered. Below is a photo or 2 of the stance I would hope to achieve, any help or recommendations? Thank you in advance for your help guys!

 

Not sure why you want the early set up.The 37 has a longer front spring than the early over axle set up.Should ride nicer.You can drop a 37 axle just like the earlier,and run a reverse eye main spring for drop.The stock 37 wishbone has more caster built in too.

 

4" dropped axle and reversed eye spring will get you almost too low to drive. Split the wishbones to the X-member.

 

If you use a 35-36 axle and wishbone in your 37, you can drop the axle a little bit more. The 33-36 axles are slightly longer from perch to kingpin, so they can stretch more for more drop. And the slightly narrower spring will give your tires more room for turning when tucked under the fenders. Make sure your wheels don't have a lot of offset.

 

You'll probably not want more than a 5 inch wide wheel on the front to have a decent turn capability if you get it pretty low. I originally have 15x6 wheels on my 1935 but the rubbed inside the fender lip. Changed it to a 15x5 and as long as I wasn't making a tight turn at any kind of speed, that fixed it. If I tried to make a tight turn... too quickly, the suspension would compress enough that the outside tire would rub inside the fender, even with the narrower wheel.

I had a MII front suspension, but the space inside the front fender will be same no matter what suspension you use.

 

You just need to narrow up the track width.
Wheel offset, tight brakes, narrow aftermarket axle, narrow (-5/8 or more) control arms.

 

If you want Low just compare your 37 unit to the 32 style and use a tape measure. You'll see the advantage of staying with what you have and just going to a dropped I Beam.

 

How does the splitting wish bones work? where to split? where to re attach? any pictures for examples?

 

enjoying your build thread

 

Agree with @alchemy If you do not have a need to split the wishbone (like using a later transmission that the wishbone wont clear) then use a 35 36 wishbone. That wish bone will allow you to use any Ford Axle from 33 to 36 and I believe a 32 as well, or a New So Cal dropped axle or Chassis Engineering dropped axle. As long as the perch bolt holes in the axle are 36 3/8" apart they will fit the 35 36 wishbone. You can have the axle dropped and bolt everything to together just the way the stock set up is now. The 35 to 40 cars and light trucks share the same spring dimensions, so you can drop the axle and use your original spring or, go super low and use a Posies reversed Eye spring (posies #2040 spring) for another 2 inches down. If you do go the Posies route. I would suggest that you hold onto the original spring for awhile after you put it all back together. It may be lower than you actually want. That way you can at least put the stock front spring back in it and gain at least an inch from not having reversed eyes.

 

no matter how you do it, you will need to drop your steering arms or use bolt on dropped steering arms. Just if your going to use bolt on steering arms, buy new repop spindles and use the bolt on arms. Save the stock ones with the arms for another build or sell them to someone that wants stock arms on the spindles, they aren't making anymore new ones with the arms on them, lets save what ever is left of them.

 

Is a pic of the 35 36 wishbone and dropped 36 axle with a Posies #2040 spring that I put together for my 39. Slick as grease and bolts right in.

 

Don't make any more work for yourself than is necessary. Your 37 axle is 48 1/2" wide and has a longer spring which gives you a better ride. Send your spring to Sid to drop it for a total of 4" drop and have him sell you some 39 plus spindles to covert to hydraulic brakes if he has any. Have him stretch the axle when he drops it to maintain the 48 1/2' width. He will send you back a droped axle that has been straightened, proper camber put in it, magnafluxed with new king pins installed, spindle arms bent to clear your bones and painted.
Read this thread about a 1935 truck build which is basically the same as a 37 except some sheetmetal differences.
https://www.jalopyjournal.com/forum/threads/35-ford-pickup-austin-speed-shop-build.986187/

 

37-41 springs are not the same as 28-36

 

You cannot drop a 37 to 40 axle 4 inches, there is not enough meat in the axle to do that between the wishbone perch bolt and the king pin.

in actuality, the amount of drop is not really 4 inches. On most axles there is already almost 2 inches of drop built in, excluding model A axles, measured from the perch bolt location. the axles have an arch to them, they are not flat. So when you drop an original axle, a supposed 4 inch dropped axle is really only dropped about 2 inches. Add the 2 inches to the original amount of drop (around 2 inches on a stock ford axle) it adds up to 4 inches. This is why using the earlier axle gets you more drop.
On a 37 to 41 axle, the distance between the perch bolt and kingpin boss is shorter, this in turn limits the amount that you can drop one to around an inch safely. As compared to the distance on the 33 to 36 axles there is a lot more meat in the axle to use to drop it, this will get you in the area of 2 to 2 1/2 inches of drop on one of these axles. See the diagram below.


Also if you are going to do the stock axle dropped route, I would NOT recommend the axle be stretch dropped. This thins out the axle end to maintain the original king pin to king pin distance. No that big a deal, but I want the thickest piece of metal I can have holding my spindle up. If it is not stretch dropped it will narrow the king pin to king pin distance in the process of dropping it. This is good, it should shorten the distance around an inch and this will pull the front wheels into the fender some and really help out with not having tires rub on fenders when turning, which is almost guaranteed to happed depending on how far down you go using the stock king pin to king pin locations.

 

You don’t need 39 spindles, 37-41 are the same, so you already have the right ones.


Sent from my iPhone using The H.A.M.B. mobile app

 

Please explain?

28 to 34 springs are similar but not the same, I can guarantee you that 35 36 springs are not the same as any earlier, as they are not installed the same, and the are two different widths. 28 to 34 are 1 3/4 inches wide and 35 36 are 2 inches wide.

35 to 40 springs will interchange, not in 41 at all. 41 will interchange with 41 to 48 front ends. 35 to 40 springs have the exact same dimensions, the only difference between them is possible leaf count differences and if it has the factory wrapped and grease-able springs on the deluxe model 39 and 40 models.

 

Your quote; "The 35 to 40 cars and light trucks share the same spring dimensions"
Are you telling me that an axle using a 36 1/2" spring center uses the same spring as a axle with a 38 1/2" spring center.

 

View attachment 4306403 View attachment 4306403

If you're referring to my post, I specifically said "drop to a total of 4" and not 4 more inches.
I had Sid drop my 37 axle a total of 4" and had it stretched to maintain the 48 1/2" per his web site.
I bet Sid has dropped 1000's of axles and find it had to believe he would do something that was not proper. I have never heard of one of his axles having a failure.
What's your expertise on dropping axles?

 

No not at all, the 35 to 40 front suspension is the same exact design and uses the same front spring. Difference is in the wish bone. The 35 to 36 wish bone is different than the 37 up wish bone. 35 to 36 wishbone uses a 36 3/8 inch perch bolt spacing and a spring in front wish bone, not the earlier spring over. the wishbone was changed in 37 to accept the newer axle design that has the wider 38 3/8 perch bolt spacing. The Spring shackle hangers on the end of the wishbone make up the difference. The 35 36 wish bone has the shackle hangars turn out toward the wheels and the 37 to 40 wishbone have the shackle hangars basically follow a straight line forward to meat the spring. The top Picture is a 37 to 40 wish bone, and the lower is a 35 36 wish bone, that is now bolted in to the front of my 39. you can see the shackle hangars are in different locations in comparison to the perch bolt locations. this allows the use of a the same spring from 35 to 40.

37 to 40 wishbone


35 36 wishbone

 

I was not referring to your post on that. I was explaining since the original poster doesn't seem to know much about this and just giving the information so that he understands what he reading and talking about. From the looks of what you are building, which looks like a really nice chassis, you are using a 37 axle in a spring over configuration, That axle was not set up that way from the factory. It was spring in front. not spring over. And you look like you are doing a fender less car, so the only thing you have to worry about rubbing is the tires to the wish bones. In that case I would stretch it to get the king pin as far from the wish bone as possible to avoid rubbing.

As far as stretch dropping it, I listen to guys that have been doing it for a long time, if you don't have to stretch drop it don't. if you thin any thing metal from what it was originally it is a not going to be as strong. that's just metallurgy. A one inch chuck of steel is stronger than a 3/4 in thick chunk of steel the same size. Will it break in what we are building probably not, but I want all the steel I can get in that area. I'm sure Sid Knows what he is doing, I never suggested he didn't. He is one of the go to guys for getting it done and does really nice work. I never said he didn't. but if you stretch drop a stock axle to maintain the 48 1/2 inch dimension, the tires are gonna rub on the fenders. Ask any one that has lowered a full fendered 35 to 40.

 

Amen. Bringing the tires inward, in any way possible, is a requirement on a fat fendered Ford that's dropped a lot. Otherwise you will hear the dreaded BRRRRRRR on every hard turn.

 

The point is that if you drop a 28-36 axle which is 50 1/2' you're going to end up with 48 1/2' and if you drop a 37-41 axle and stretch it, you have the same 48 1/2" measurement. If you drop the 37-41 and don't stretch it, you will get 46 1/2" but I hear it makes things pretty tight around the spindle arms maybe hitting the bones.

 

What an amazing thread!

 

I Intend to go with a small block Chevy and a GM gearbox (not sure which yet) so the wishbone will have to go is my understanding. just hunting on ebay and speedway motors has reverse eye leaves and 4" total drop axles with a four bar kit to replace wishbone set up. anybody have experience with this set up?

 

You can drop existing axle and use a kit like from Pete and Jakes which has a motor mount for a turbo 350 tranny.
https://www.peteandjakes.com/wp-content/uploads/2016/10/5007A-front.pdf

https://www.peteandjakes.com/parts/part-5007a-1935-40-trans-mount-split-wishbone-kit-350-chv/

 

I'd recommend splitting the stock wishbone (or a 35/36 if using a narrower axle) before going with an aftermarket 4-bar. Much more tire clearance while turning.

 

Boy, this right where I am at, trying to put together a plan for the front suspension on my 37 Ford truck project. Loving all this info.
Mike

 

Lots of great information.

 

Agree with Alchemy