Undertaking a underslung straight axle

Reply Subscribe

Thread Tools

Search this Thread

Apr 26, 2025 | 10:59 PM

stormystorm1

Thread Starter

5th Wheeling

Joined: May 2024

Posts: 44

Likes: 6

Undertaking a underslung straight axle

Good evening good morning hello,

I’ve got a 1957 f100 inline 6 truck it’s bare bones I and I want to keep it more traditional then the CV swap. I got a static drop so far of 4” around the truck and want a little more. The back end was flipped and I need to c-notch to get the full drop. The front end I shuffled the leafs a removed two.
But I want to go lower. I’ve got about 3” in between the oil pan and axle. I want to go underslung with welded in boxes.

The main thing I’m trying to sort out is the ubolt hole width and length. For the bottom of the axle I’d like to use a prefabbed leaf spring plate if possible to safe some time.

From what I can tell a jeep xj and yj leaf spring plate may work. I can get these for less than $10 if they’d fit it be a home run to weld them in top of boxing plates to my axle.

can anyone verify that? I can’t find a dimensions sheet or schematic anywhere that list the measurements?

As it sits now

When I first got her home

I plan to move the steering box up and adjust to make the steering right again. So bump steer I am planning to emlinate. This will never be a show truck just a static slam crusier for small town drives.

Apr 30, 2025 | 08:43 PM

FuzzFace2

FTE Legend

Joined: Nov 2015

Posts: 30,960

Likes: 4,129

From: Angier, NC

Have you looked into a dropped front axle beam this way you keep some space between the axle and oil pan and keep the suspension travel without bottoming out.
If I lower anything I like to keep the travel as close to factory as I can for the ride.
Dave ----

May 5, 2025 | 10:55 AM

JohnNewb

Fleet Mechanic

Joined: Feb 2019

Posts: 1,388

Likes: 92

From: California High Desert

If you like slammed, it looks pretty good as it is. It would not make it down my road now.

May 18, 2025 | 06:23 PM

stormystorm1

Thread Starter

5th Wheeling

Joined: May 2024

Posts: 44

Likes: 6

Quote:

Originally Posted by JohnNewb

If you like slammed, it looks pretty good as it is. It would not make it down my road now.

holy cow I’ve been busy. It’s wierd times being a fed employee these days. Been more worried about losing my job then my project.

id like to eat pavement. So we’ll have to see. I’m mostly paved roads in the eastern sierra.

if I tuck too much I won’t be able to turn

May 19, 2025 | 08:06 PM

spurredon

FTE Legend

Joined: Jun 2004

Posts: 32,078

Likes: 2,434

From: Upstate NY

I have a couple of trucks that look that low sitting in the lawn, but it is because their tires are flat and starting to sink in the ground! HaHa!

May 19, 2025 | 11:17 PM

stormystorm1

Thread Starter

5th Wheeling

Joined: May 2024

Posts: 44

Likes: 6

Quote:

Originally Posted by spurredon

I have a couple of trucks that look that low sitting in the lawn, but it is because their tires are flat and starting to sink in the ground! HaHa!

nice I’ve got a pretty good idea on a 2” spring plate and some bushing to get it under the axle.

funds are a shot tight with job uncertainty but hey YOLO