Leaf spring problems

[JBNeal]

additional information - Leaf Spring Lubrication and Finishes

[bkahler]

1 hour ago, Merle Coggins said:

I'm with Jeff on this. I've never had my spring packs apart. I sprayed them down with penetrating oil a couple times early on. Now I'll add a spray down with a dry lube spray every couple of years. I'm always amazed how well it rides for a 70 year old 3/4 ton truck.

 

I'm wondering how my trucks going to ride with this leaf spring stack

 

Edited January 9, 2020 by bkahler

[Merle Coggins]

Can't be any worse than mine, although you have a shorter wheel base. The longer trucks tend to smooth things out a bit more.

[bkahler]

34 minutes ago, Merle Coggins said:

Can't be any worse than mine, although you have a shorter wheel base. The longer trucks tend to smooth things out a bit more.

 

Merle,

 

Your's is the first one I've seen that also has the extra overload springs installed.  Based on the picture it looks like you might have a few more leafs in the lower stack.  I think my lower stack has 6 and the upper has 7 leafs.

 

Brad

[Todd B]

5 hours ago, Merle Coggins said:

I'm with Jeff on this. I've never had my spring packs apart. I sprayed them down with penetrating oil a couple times early on. Now I'll add a spray down with a dry lube spray every couple of years. I'm always amazed how well it rides for a 70 year old 3/4 ton truck.

That’s because your daily work truck is a Ford

[Tooljunkie]

Back end is getting a diplomat 8.25” and dodge a body leaf springs.

i tried rear shocks from the dart, if  i didnt lower Fargo so much, they would work perfect on the front. 
still working on ride height, so i may be able to use them. 
 

[Tooljunkie]

Spent the day welding plug into old hole,machined out some sleeves to press new bushings in. Bored holes in frame, mounted square tubes and a quick test fit with an overbored sleeve. 
next is new shackles.tack it all together and see how it sits. 
very happy with today’s progress. 
 

[Radarsonwheels]

Nice progress way to get in there and do what needs doing

[Plymouthy Adams]

19 minutes ago, Radarsonwheels said:

Nice progress way to get in there and do what needs doing

I agree, often the hardest part of the job is committing yourself to the task.....

[Tooljunkie]

Way i see it is design as you build. 
i enjoy fabrication work. There are less forseeable problems now than yesterday. After years of wrenching this stuff gets easier all the time. Sure is a nice break from certified auto technician’s daily grind. 
figure i got it 2-1/2” lower, but the rad support repair moved the fenders back up at least 1/2 that. 

thanks for your words of encouragement. 

[Tooljunkie]

Made a spacer to match the axle, so the spring centre pins are correct dimension. 
drilled my other mounting bolts that hold bracket in frame. Now for some welding. 

[Radarsonwheels]

On 1/9/2020 at 6:57 PM, Tooljunkie said:

Back end is getting a diplomat 8.25” and dodge a body leaf springs.

i tried rear shocks from the dart, if  i didnt lower Fargo so much, they would work perfect on the front. 
still working on ride height, so i may be able to use them. 
 

Hey so I have the dart A-body xhd six leaf springs under my truck- maybe I can help out with some info you might already know. 
 

-the front segment of the springs is shorter than the rear. This is good because it is stiffer and can act more like a trailing arm while the back of the spring does more of the work flexing. This gives less spring wrap and pinion angle change on acceleration but you might need to move your front spring perches back to center the wheels in the tubs.

 

-where ever your shackle perches end up you want them in front of the rear spring eye with the weight of the truck on them. Any position that holds up the truck and doesn’t bind will work but under acceleration the rear spring eye actually moves forward as the spring wraps up, which is a little counterintuitive- seems like the spring would get longer not shorter.
 

Anyway, the bottom shackle eye moves in an arc below the upper shackle perch so when it’s vertical it is lifting the chassis up the highest it can go. If you have the bottom eye behind the upper pivot point on the perch what happens on a launch is the spring eye moves forward and down and tries to lift the chassis as it swings in an arc. 
 

Mounted with this geometry the weight of the truck is loaded onto the tires when you drop the hammer. If it starts out vertical then it unloads weight off the tires when you launch, which is not what you want.

 

All this is kind of drag strip stuff which has absolutely nothing to do with driving to the ice cream shop or hauling bales of hay but if you’re gonna do it why not get the angles right?

 

of course maybe I’m preaching to the choir!

 

good luck amd post more pics I love seeing this stuff!

 

Rdr

[Tooljunkie]

Hadnt thought about that much. 
makes perfect sense.on the front i set springs under frame and let the weight settle. Then made my vertical line. When all is said and done they are vertical at rest with load on. 
will follow same steps with the rear springs. Only issue is the box will be off. I will come up with a load to keep weight close. Maybe set it up with a little extra weight to be on the safe side. 

[Tooljunkie]

1 hour ago, Radarsonwheels said:

Hey so I have the dart A-body xhd six leaf springs under my truck- maybe I can help out with some info you might already know. 
 

-the front segment of the springs is shorter than the rear. This is good because it is stiffer and can act more like a trailing arm while the back of the spring does more of the work flexing. This gives less spring wrap and pinion angle change on acceleration but you might need to move your front spring perches back to center the wheels in the tubs.

 

-where ever your shackle perches end up you want them in front of the rear spring eye with the weight of the truck on them. Any position that holds up the truck and doesn’t bind will work but under acceleration the rear spring eye actually moves forward as the spring wraps up, which is a little counterintuitive- seems like the spring would get longer not shorter.
 

Anyway, the bottom shackle eye moves in an arc below the upper shackle perch so when it’s vertical it is lifting the chassis up the highest it can go. If you have the bottom eye behind the upper pivot point on the perch what happens on a launch is the spring eye moves forward and down and tries to lift the chassis as it swings in an arc. 
 

Mounted with this geometry the weight of the truck is loaded onto the tires when you drop the hammer. If it starts out vertical then it unloads weight off the tires when you launch, which is not what you want.

 

All this is kind of drag strip stuff which has absolutely nothing to do with driving to the ice cream shop or hauling bales of hay but if you’re gonna do it why not get the angles right?

 

of course maybe I’m preaching to the choir!

 

good luck amd post more pics I love seeing this stuff!

 

Rdr

Thanks. You built your  spring Hangers?  
as far as dropping the hammer goes, its more like a pillow. The 218 leaves something to be desired in that department. 
But i should set it up decent, no telling what i may trip over in the future. 

[Radarsonwheels]

I took stock dakota hangers, flipped them sideways so my slapper bars could still hit the front spring eyes, enlarged the pivot hole to take the bigger bolt, moved them up and back for the static chassis drop, and plated/reinforced them into the frame rail. But I have over 500 ft/lbs just off idle so I wasn’t messing around. I also cut off the rear hangers and moved them to get the shackle angle right. 
 

look on page 3 of my build thread you can see them getting located and tacked in before I reinforced them

[Merle Coggins]

30 minutes ago, Tooljunkie said:

... Only issue is the box will be off. I will come up with a load to keep weight close. Maybe set it up with a little extra weight to be on the safe side. 

 

Sometimes you do what you gotta do to add a little weight to a bare frame. When I swapped in my 3.73 diff I was still in the overall building stage, with no body work on the chassis yet. The driveshaft was tight to get off the yolk at the diff, but I couldn't get it back in to save my live. Since I was working in our heavy equipment shop, I looked around the shop and spotted an excavator bucket. BINGO!! Set it on the frame with the overhead crane enough to squat the springs and give me the necessary clearance for the driveshaft to slip in place. (sorry, my camera didn't focus too well on this one)

[Tooljunkie]

Update, got rear  bushing tubes welded, and installed. Shackles made and everything hung where its close to its final resting place. 
a few photos to show progress. 
sorry about sidewards Photos. 
5” between snubber and frame, just under 2” now. Will trim snubber if it becomes an issue. 
can see the reversed eyes on the top leaf, that was near 2” on its own. 

[bkahler]

I'm curious about the limited amount of travel that appears to be present due to how close the spring is to the bump stop.  Are you planning on a stiff suspension or is this the normal orientation?  My  B3B has something like 6 to 7 inches of travel.

 

 

[Tooljunkie]

Think there was originally 5”. 
will take 1” off bump stop. New  Shocks will help. 
this wont be seeing much for rough stuff any more, just a putt to town for parts or lunch. 

[bkahler]

Shortening the bump stock makes sense.  

 

So........no high speed trips anymore........right...........   ?

[Tooljunkie]

And with the new style bushings,urethane will slow the spring action as well. 

Edited January 19, 2020 by Tooljunkie

[Tooljunkie]

Well it’s getting closer. While revamping front   suspension I decided i should address the poor attempt at frame   repair. Cut Off old plate and leaf  spring That was welded To frame, re-aligned crack and gave it a fish plate. Will eliminate any concerns i had.