Going Back...

[Millardo]

I'm going back to stock springs on my '72 build. The the after market Spector Offroad springs are just too painfully stiff for this Sunday cruiser.
Stupid question though, as I dug them out of the shed... Two are flatter than the other two. Which are the front and which are the back?

Running 33 x 9.5 x 15. Imagine I will need a bit of an extended shackle.

 

[igotta40]

Nice truck! I’m pretty sure you can tell front from rear by the number of springs. Not sure if it matters which is right or left unless they have taken a set.

 

[Mark Jennings]

That’s a great looking FJ40…. So I run Skyjacker springs and like yours, are by no means a soft ride. I also run Rancho RS9000 adjustable shocks set at the ‘softest’ setting. What really improved the ride was running 25 PSI (from 30) on 31 10.50 15 tires. That made it reasonable.

Have you played with tire pressures to improve the harsh ride? These rigs don’t weigh that much, and sidewall flex does make stiff springs a bit more tolerable. I realize lower tire pressure is a compromise….. however, beats the work required to change springs out.

 

[77mustard40]

If you’re a full time top off kind a guy I recommend removing a leaf from the rear packs. Otherwise you need to add a couple hundred pounds of sand or cement bags from HD to help flex and break in the rears.

 

[Jdc1]

@Millardo ‘s and @SSCR ‘s threads got me into a lot of trouble….

 

[Millardo]

Thank you everyone for your reply.
Yes, full time top off. And I don’t want a couple hundred pounds of sand bags as passengers .
I have messed with the current SOR springs and concluded they were just too stiff…

These are the old set. Which are front and back? The flatter springs have 7 leafs, and the more arched springs have 6 leafs.

After putting the old springs back on, I will have to play with shackle length to clear my 33 x 9.5’s.
I like the greaseable anti reverse. Any suggestion on length to clear those tires?

 

[Pighead]

A long, long time ago, I had my original springs re-arched. I found my friendly local Blacksmith/spring shop in the yellow pages (yes, that long ago). That might be a thought for your springs, if you can find a Blacksmith these days. There might be an inch or two of unused height in your springs, you might be able to get by with shorter shackles. Paint and lube the leaves while you're in there...
Factory leaf pack on a 55 was 7 in front, 8 in the back

 

[Grayscale]

Seven leaves up front, six in the back. I'm not sure that those springs are warranted, based on the tire size, or desire for a smoother ride.

My opinion: I've seen folks run stock springs with spring-over-axle conversions, but, that is a whole new game where they were making some serious rigs. Coil springs make quite a bit of sense, but then you are basically talking about a different vehicle. The pre-sway bar suspensions... Suspension stiffness isn't going to go away that easy, until your leaf springs are essentially not arced at all, but that is tricky. Really tall shackles on stock springs comes with a front castor and rear driveshaft issue.

 

[Mark Jennings]

A long, long time ago, I had my original springs re-arched. I found my friendly local Blacksmith/spring shop in the yellow pages (yes, that long ago). That might be a thought for your springs, if you can find a Blacksmith these days. There might be an inch or two of unused height in your springs, you might be able to get by with shorter shackles. Paint and lube the leaves while you're in there...
Factory leaf pack on a 55 was 7 in front, 8 in the back

Most major truck stops have resources to re arch and actually provide new springs….let your fingers do the walking…not Yellow Pages….Google….

Tell em, what you want, get out your check book….

Bee Good!

 

[Millardo]

Seven leaves up front, six in the back. I'm not sure that those springs are warranted, based on the tire size, or desire for a smoother ride.

My opinion: I've seen folks run stock springs with spring-over-axle conversions, but, that is a whole new game where they were making some serious rigs. Coil springs make quite a bit of sense, but then you are basically talking about a different vehicle. The pre-sway bar suspensions... Suspension stiffness isn't going to go away that easy, until your leaf springs are essentially not arced at all, but that is tricky. Really tall shackles on stock springs comes with a front castor and rear driveshaft issue.

I’m not sure what you mean with reference to those springs being “warranted” for the tire size and desire for a smoother ride. Are you indicating the stock springs pictured won’t accommodate the 33x9.5’s and won’t be a softer ride than the SOR heavy duty springs currently on the vehicle?

 

[knuckle47]

Here in NJ there are auto spring shops everywhere….they can work wonders on steel springs… I did this on my stock FJ40 almost 50 years ago for those Armstrong Tru-Tracs. I believe they were 33” maybe 34”. At work, there is a spring shop who told me months ago to drop them off and I could pick them up 2 days later for $200.00 , all four, if I remember correctly.

I’ve decided to try those parabolic springs for my softer ride. They’re a crazy expensive experiment but I really need a softer ride at this age. 40 channel on YouTube has an interesting comparison

 

[Millardo]

Worked on these SOR springs today and did a test. The photos are still frames taken from video at max compression of the spring with me (230lbs) bouncing on the rear bumper. The arrow and the highlighted jack stand head is an attempt to show the flexion.
The shackle bolts are just snug enough to flatten the lock washers.
The shocks are SOR ProComp Explorer’s from 1998 when I installed both the shocks and springs.
The kit was a 4” lift I believe, with 2”s coming from springs and 2”s from extended shackles that I did not install because I stayed with 33x9.5s. There is only 200 miles on the rig since installation. I did use ramps on opposing corner wheels overnight and wd40 between leafs best as I could.

How does the shackle angle look at maximum flexion, and is that good compression for 230lbs bouncing on the rear bumper?

I took video which really illustrates better, but I couldn’t figure out how to upload the short clips.

 

[Millardo]

Here in NJ there are auto spring shops everywhere….they can work wonders on steel springs… I did this on my stock FJ40 almost 50 years ago for those Armstrong Tru-Tracs. I believe they were 33” maybe 34”. At work, there is a spring shop who told me months ago to drop them off and I could pick them up 2 days later for $200.00 , all four, if I remember correctly.

I’ve decided to try those parabolic springs for my softer ride. They’re a crazy expensive experiment but I really need a softer ride at this age. 40 channel on YouTube has an interesting comparison

Thank you for the info knuckle47. I sure would like to get this rig riding soft enough to enjoy a Sunday drive. It was my college car in 1987, now it just gets driven a couple times a year along the coast on a sunny day.
I will checkout the 40 channel.

 

[77mustard40]

Worked on these SOR springs today and did a test. The photos are still frames taken from video at max compression of the spring with me (230lbs) bouncing on the rear bumper. The arrow and the highlighted jack stand head is an attempt to show the flexion.
The shackle bolts are just snug enough to flatten the lock washers.
The shocks are SOR ProComp Explorer’s from 1998 when I installed both the shocks and springs.
The kit was a 4” lift I believe, with 2”s coming from springs and 2”s from extended shackles that I did not install because I stayed with 33x9.5s. There is only 200 miles on the rig since installation. I did use ramps on opposing corner wheels overnight and wd40 between leafs best as I could.

How does the shackle angle look at maximum flexion, and is that good compression for 230lbs bouncing on the rear bumper?

I took video which really illustrates better, but I couldn’t figure out how to upload the short clips.

View attachment 3714628

View attachment 3714629

View attachment 3714630

View attachment 3714631

Nothing wrong with those angles, vids need to go to YouTube and then you can paste a link.

IMHO shocks make a big ride quality difference. Years ago I ran the OME yellow shocks and they were brutal on a 40. Switched to Bilstein and it was way better. Today the cats meow may be Dobinsons IMS but I can’t bring myself to drop that kind of coin on a shock for a 40. It’s never going to ride great, but I love the IMS shocks on the 80 and 100 series.

I don’t have experience with your shocks, but technology has come a long way and there could be a better choice for the use of your 40. I don’t want to spend your $, actually I do but on my 40. Just kidding, good luck sorting it out, it’s a fantastic looking 40.

 

[Millardo]

Nothing wrong with those angles, vids need to go to YouTube and then you can paste a link.

IMHO shocks make a big ride quality difference. Years ago I ran the OME yellow shocks and they were brutal on a 40. Switched to Bilstein and it was way better. Today the cats meow may be Dobinsons IMS but I can’t bring myself to drop that kind of coin on a shock for a 40. It’s never going to ride great, but I love the IMS shocks on the 80 and 100 series.

I don’t have experience with your shocks, but technology has come a long way and there could be a better choice for the use of your 40. I don’t want to spend your $, actually I do but on my 40. Just kidding, good luck sorting it out, it’s a fantastic looking 40.

Thank you for the info AND the kind words!

 

[Millardo]

I found the stickers I never used on the shocks. Anyone have any input on these, other than what the product website says?

 

[Grayscale]

I’m not sure what you mean with reference to those springs being “warranted” for the tire size and desire for a smoother ride. Are you indicating the stock springs pictured won’t accommodate the 33x9.5’s and won’t be a softer ride than the SOR heavy duty springs currently on the vehicle?

Decades ago, I bought a truck with long shackles, stock springs. Then I bought 33x12.5 tires, and I rubbed the treads the first day I took them out. The spot was where the tub does a 90-degree turn behind the front seats; I immediately did some damage to a fresh set of BFG Mud Terrains. Then I did a 2-inch Rancho lift with longer shackles, I still had problems rubbing. I was really pushing that vehicle; I was in my early twenties and in need of all-kinds of lessons. I wasn't running much weight, no doors, just a couple of loops for a roll cage and bikini top. The tires you mention are narrower, and I was using an 8-inch rim, iirc.

Yes, the stock springs will be a softer ride, they are arched less, which helps. I'm currently using OEM shocks and springs, with 215-75-R15, with less than 28-psi. I'm really happy with the ride like this, but the truck, as a project, looks kinda derelict, which I actually appreciate a bit. Paved-road irregularities in a spring-under-axle 40 have always been nerve-racking, compared to anything else I've been in.

Yours has a proper appearance. Changing to stock springs, with longer shackles (anti-inversion-type) requires shims and longer sping pins to correct the angle of the spring perch, both front and back. A somewhat vertical shackle angle tends to resist flexing, or at least that is my impression

Hence, "warranted" - meaning deserved, or necessary to match those tires with those springs. How much are those treads inflated?

 

[Millardo]

Decades ago, I bought a truck with long shackles, stock springs. Then I bought 33x12.5 tires, and I rubbed the treads the first day I took them out. The spot was where the tub does a 90-degree turn behind the front seats; I immediately did some damage to a fresh set of BFG Mud Terrains. Then I did a 2-inch Rancho lift with longer shackles, I still had problems rubbing. I was really pushing that vehicle; I was in my early twenties and in need of all-kinds of lessons. I wasn't running much weight, no doors, just a couple of loops for a roll cage and bikini top. The tires you mention are narrower, and I was using an 8-inch rim, iirc.

Yes, the stock springs will be a softer ride, they are arched less, which helps. I'm currently using OEM shocks and springs, with 215-75-R15, with less than 28-psi. I'm really happy with the ride like this, but the truck, as a project, looks kinda derelict, which I actually appreciate a bit. Paved-road irregularities in a spring-under-axle 40 have always been nerve-racking, compared to anything else I've been in.

Yours has a proper appearance. Changing to stock springs, with longer shackles (anti-inversion-type) requires shims and longer sping pins to correct the angle of the spring perch, both front and back. A somewhat vertical shackle angle tends to resist flexing, or at least that is my impression

Hence, "warranted" - meaning deserved, or necessary to match those tires with those springs. How much are those treads inflated?

Thank you for that, I get it…
I do like the appearance/visual of my current set up, and I prefer the non-extended shackle look. I was afraid the stock shackle length was keeping the spring from flexing. I posted a few photos, but the video of the shackle movement with me bouncing on the bumper after I took the shocks off shows pretty good movement. I think.
I will upload to YouTube and post a link. Not sure what the tire pressure was when I drove it last. I believe the tire calls for 50psi.

 

[77mustard40]

Don’t inflate the tires to 50, that’s probably the manufacturers max inflation. Start at 30 and pull through a wet spot in the drive to see the contact patch. Make small adjustments to dial it in, your butt will help with the reading as well

 

[Millardo]

Link to YouTube bounce test video.

With shocks-

Without shocks-