Featured Technical 40-41 FORD PICKUP PARALLEL LEAFS

Beautiful truck, but that’s my pet peeve when the wheel isn't centered in the fender. Wish there was an easy way to fix the front wheels from rolling back when you drop one down, it bugs me as well. On the back I had to cut out the setup I had under my 36 coupe because the rear crossmember was chopped and welded back crooked, throwing the rear end sideways. After I measured and drilled for my new weed eater leave springs, Had Wrenchbender weld in my rearend after setting pinion angle. Car sat high with new springs, winter was full on so couple months go by and I pull the tarp back to find the rear had settled and went backwards an inch or so. It was a real gut punch kick in the balls. I got some adjustable lowering blocks from speedway and dialed them in.

 

V8 Bob, I've heard that B-B's ch***is guy was over the top **** with his tape measure. Also, it sounds like this wasn't his first time doing parallel springs on an early Ford Ch***is. Seems quality control, or Lack of by the spring supplier probably caused the issue being I know there was room built in for 1.5" of settlement and hit near the exact mark of tire in opening in these photos. He also expected to use up to maybe a 1/2" block to hit the Exact mark after things stopped moving. To use a lowering block to dial in the tire to Center on each side is Not something he would do ever. To do that the Axle Housing would no longer be correct to ch***is square. I know for a fact he has totally reset the tire openings in fenders to make tires dead center on many projects. He's also one of those Guys that you only Primer and Paint over his Tin Work. That said there was not a Bed with fenders on it to set Tire Center line to instead just a factory Blueprint. I would have matched the Driver Side to the tire opening so it looked better when the driver walked up to it. It's Just Old Car issues.

 

I would still first verify the axle alignment when making any rear WB or body change, because I know first hand it doesn't take much axle movement (+/- 0.10") to visually throw a wheel off center on a '40 style fender, especially with 2 1/2'- 2 3/4" whitewalls!

I'll probably take some heat, but B B's ch***is guy installed the front C.E. spring eyes too high for this (un-zeed) ch***is, causing the problem, not C.E. or their springs. Kerrynzl's post stated it better. A different parallel rear kit should have been used, OR those dreaded lowering blocks, knowing they may be needed to attain the desired at***ude.

Merry Christmas!

 

I am not a lowering block fan. Like electric fans, they are Band-Aids in my mind to fix an issue that could have been better engineered from the start. That said, buying someone else's build, you have to do what you have to do to fix it, make it sit to your liking and not overheat. I'm not being judgmental; hell, I have an electric fan on my roadster because I couldn't come up with a way to use an engine mounted fan with that supercharger on the flathead. It still bothers me 10 years later.

If this shackle install doesn't fix it, I will take those springs out next. For now, it looks good. I like the shackles, they are much nicer than what was there, and they are invisible under the truck bed and fenders. I need a nice day and maybe your ***istance so I can get some miles on it and see if the springs continue to fall. I have no faith in them at all at this point.

You did your job perfect! The front end and rear axle are square in the frame as verified by laser measurements at Dabney's. The pinion angle was dead on as well. I am anxious to see if the truck still has that harmonic vibration at 40 MPH.

@Pist-n-Broke is my ch***is guy. He has done this leaf install many times and he is very **** retentive in his "measure 10 times, cut once" approach. He made no error, we expected an inch in settling and got 2.5". **** happens. I hope I have it fixed, but I don't trust the springs. No leaf should reverse arch. A friend of mine has a 65 D100 van with the exact same springs. His are 60 years old, he removed a couple springs to lower the van when he was in HS, they still aren't reverse arched and the hold the weight of the engine.

The first place the truck went once it was a driver was Dabney's alignment shop in town. They are the best of the best around here. It is square. Unlike a coupe or sedan, a pickup's rear fenders are dependent on the truck bed. That is a reproduction bed and if they didn't stamp the square mounting holes exactly correct the fender aint gonna fit perfectly. The running board and front fender also play a role in where that fender ends up, same as a p***enger car. I do have a bit more fender overhanging that side, but the axle is centered in the frame. That fender was a 40/41, the right rear fender was a 47 that I cut up and spliced together to make it fit the truck. Again, perfection on a commercial vehicle is hard to obtain. I am thinking about adding a 1/4" spacer to the left wheel to bring it out a touch and match the other side.

 

Next up (down?), is to build a skid plate under the transmission pan. That ****** is low and there are witness marks in the paint job I put on that oil pan that I have dragged it slightly. Likely due to the rear springs failing but better safe than sorry. I have a good plan on fabricating one, just gotta get to it.

And I have to get the buffer out and polish the tail pipes, they have scratches running the length of them from the *** of the truck sagging.

 

No Bob, you're not going to get any heat from me. I've been around Opinions all my life (I'll be 80 in 11 months). I haven't been on the HAMB very long but have noticed that everybody here has there's too (that includes me). Few customers ever got to walk in while I was working and see my Data liner and Lazer in action. B-B's truck came to me out of a deceased family members estate. This is a never posted before on the HAMB photo of the day I picked it up. It was wearing those springs at that time.

Here's yet another taken the same day. This next photo shows the springs in place via kit and notice a full 6" lowering block.

Sometimes we try to work with what comes with a package and it doesn't work out as well as we expect. Kinda like some opinions come from people not fully informed.

 

A fabricator can do amazing work to a high standard but still not understand the principles of suspension geometry

Move the front spring eyes down 2" will raise the truck 1" + [depending on the center-bolt location] and also correct the geometry.
The springs need to be mounted on an angle with the front eyes lower than the rear eyes.
When the spring compresses and lengthens along the datum line [blue arrow] , the axle also arcs forward [red arrow] counteracting this [causing a vertical path of travel]


You will need to correct the pinion angle after doing this.
You can correct some of the pinion angle by re-arching the springs from behind the axle tubes [after lowering the front spring eye] this will raise the height a bit more.

If you're smart enough to build a hotrod ,you are smart enough to DIY cold reset springs [make a leaf spring reset jig from s**** steel]