52/56: Less travel in back than in front?

[dremu]

I'm measuring for shocks and cycling the suspension -- which is actually quite fun, remembering basic safety of course. I get to use the hydraulic jack AND the Hi-Lift (and a stand or two)... big fun.

Anyway, on the front 52"s, looks like I have about 4" up travel and 6"+ down, so I'm happy there.

In back, however, the 56"s only compress like an inch and a half, though they do droop ~7". That doesn't seem like much up travel; is it normal for the front to be flexier than the rear, or is there something wrong? Springs sagging, due to excessive loading or worn out leaves? Bad geometry? Umm, here's my shackle angle, passenger side, at rest.

Other thoughts?

-- A

 

[Blazinaire]

If you are just measuring articulated travel, then yes it is normal for the front to move more than the back (using similar leaf packs such as 52/56) due to the front spring spacing being narrower (therefor having more leverage against them) compared to the rear. If you are referring to straight up and down travel, then... umm?

 

[dremu]

If you are just measuring articulated travel, then yes it is normal for the front to move more than the back (using similar leaf packs such as 52/56) due to the front spring spacing being narrower (therefor having more leverage against them) compared to the rear. If you are referring to straight up and down travel, then... umm?

I'd forgotten that the spring track width or whatever you wanna call it is different from & rear, so that make sense.

I'm measuring from, say, the hub to the wheel well as the spring moves, so yeah, I'd assume that's articulated travel.

It's not really straight up & down 'cuz the whole truck kinda shifts as I'm doing it, if that's whatcha mean?


-- A

 

[yellowK20]

Front is also 30-40% heavier then the rear so it will tend to compress the springs further

 

[Hogback Fabrication]

Totally depends on the spring packs as well, leaf springs typically get stiffer in compression and softer in droop.

What do your leaf packs look like?

 

[dremu]

Totally depends on the spring packs as well, leaf springs typically get stiffer in compression and softer in droop.

What do your leaf packs look like?

Well, they look like flat pieces of metal in long skinny shapes, stacked together... (sorry, seen "Airplane!" too many times. )

Seriously (don't call me Shirley!), donno exactly what to tell you on the springs. The fronts are 52"s, five leaves plus overload. The rears are 56"s, seven leaves plus overload. Both are used stock sets.

Though, hmm, as I think about it, a few of the leaves in the rears are a mite wiggly in shape, less arched than their friends. There's a coupla spots where there's a visible gap between leaves. I was gonna leave them (as it were) and see if they settled in. Though I thought the failure mode for worn-out springs was to be softer, not stiffer.

And yeah, now that you mention it, it makes sense that they'd droop more 'cuz they're arched that way and it's harder to push the arch flat than it is for it to arch more.

-- A

 

[Gunny65]

If your springs are messed up you could always use them to...make a hat, or a broach, or a teradactyl!

And.....if you need new ones....There's a sale at Penney's.

Seriously (don't call me Shirley!),
-- A

 

[imiceman44]

Well, they look like flat pieces of metal in long skinny shapes, stacked together... (sorry, seen "Airplane!" too many times. )

Seriously (don't call me Shirley!), donno exactly what to tell you on the springs. The fronts are 52"s, five leaves plus overload. The rears are 56"s, seven leaves plus overload. Both are used stock sets.

Though, hmm, as I think about it, a few of the leaves in the rears are a mite wiggly in shape, less arched than their friends. There's a coupla spots where there's a visible gap between leaves. I was gonna leave them (as it were) and see if they settled in. Though I thought the failure mode for worn-out springs was to be softer, not stiffer.

And yeah, now that you mention it, it makes sense that they'd droop more 'cuz they're arched that way and it's harder to push the arch flat than it is for it to arch more.

-- A

Are the rears the ones you got from me?
They had an add a leaf in them, did you take it out?

 

[dremu]

If your springs are messed up you could always use them to...make a hat, or a broach, or a teradactyl!

And.....if you need new ones....There's a sale at Penney's.

First the dinosaurs came, but they got fat and died. Then the Arabs came and they bought Mercedes Benzes...

That movie is sooo hilarious in pieces; it's only if you have to watch the whole thing that it sucks

Are the rears the ones you got from me?
They had an add a leaf in them, did you take it out?

Yes on both counts. I wasn't gonna name names publicly

The center pin wasn't real tight; whoever put in the AAL didn't torque it properly, and I think they've suffered some for it being loose.

-- A

 

[imiceman44]

First the dinosaurs came, but they got fat and died. Then the Arabs came and they bought Mercedes Benzes...

That movie is sooo hilarious in pieces; it's only if you have to watch the whole thing that it sucks



Yes on both counts. I wasn't gonna name names publicly

The center pin wasn't real tight; whoever put in the AAL didn't torque it properly, and I think they've suffered some for it being loose.

-- A

I didn't do anything with these springs, they came from Kidjethro's truck, he did all that work.
The reason I was asking if the AAL where still on is because you said they were too stiff, but if not on anymore then it's just the fact you have no weight on the rear so you can't really flex them well.
Try putting an engine in the bed, just strap it very well so it doesn't roll all over the place when you flex it.
Oh and don't get me started on Airplane or naked gun, I have watched those movies million times and everytime I do, I quote them for days.
My favorite type of movies.

 

[dremu]

I didn't do anything with these springs, they came from Kidjethro's truck, he did all that work.
The reason I was asking if the AAL where still on is because you said they were too stiff, but if not on anymore then it's just the fact you have no weight on the rear so you can't really flex them well.
Try putting an engine in the bed, just strap it very well so it doesn't roll all over the place when you flex it.
Oh and don't get me started on Airplane or naked gun, I have watched those movies million times and everytime I do, I quote them for days.
My favorite type of movies.

Unlike some people, I don't keep spare engines sitting around.

Chevy Chase movies are like that ... Caddyshack. Horrible, awful movie to watch beginning to end ... but in pieces, it's fantastic.

Anyway, on topic (can you hijack your own threads? Is that even legal in the Bible Belt?) it sounds like things are normal, so I'll continue about my business. These are not the droids I'm looking for...

-- A

 

[blazinzuk]

Just remember you will never get something fully articulated with a hi lift and floor jack.

You really need to do the engine hoist thing to get the wheels to force down and then you only really get uptravel, down travel can still be forced to a certain point. Which is hard to replicate in a driveway

 

[dremu]

Just remember you will never get something fully articulated with a hi lift and floor jack.

You really need to do the engine hoist thing to get the wheels to force down and then you only really get uptravel, down travel can still be forced to a certain point. Which is hard to replicate in a driveway

That makes sense. I got shocks with more travel than I measured, and I should have enough leeway in mounting them that they will not be the limiting factor in either direction.

-- A

 

[4X4HIGH]

This may sound like a silly question but did you remove the current shocks before trying to check for compression/droop?

 

[dremu]

This may sound like a silly question but did you remove the current shocks before trying to check for compression/droop?

Hey, with me, you never know

But yes, I took the old ones off, so I was measuring the suspension's actual travel, not shock-limited.

-- A

 

[4X4HIGH]

So why are you so worried about flex anyways, I thought you were like me and only web wheeled.

 

[dremu]

So why are you so worried about flex anyways, I thought you were like me and only web wheeled.

Sheeeit, the way that truck is going, Greg will get his to BlazerBash before I do!

Wasn't worried per se, just sizing for shocks and curious about what I found.

-- A

 

[cybrfire]

Ya just about got to have two engine hoists to really flex it. I got alot more in Moab than I ever did at the shop with a fork lift. Drivers front and passenger rear and lift 'em.

 

[blazinzuk]

The only thing I check is stuff when sizing for shocks. For one reason. It is very hard to replicate droop unless in the real world.

So on front springs I measure for bumps to where the spring will be flat then I put whatever brand you want shock that has 14" of travel up there.

Put it so that you have an extra inch of travel in the shock up. Use the rest for down, you will use it all.

In the back it depends on how you are mounting shocks you have quite a bit of weight in the back so I might just put the bumpstops before the spring gets flat and once again see how much shock you are going to use. Put the longest one on there as you will use all the down travel

 

[K85 Octane]

So on front springs I measure for bumps to where the spring will be flat then I put whatever brand you want shock that has 14" of travel up there.

Put it so that you have an extra inch of travel in the shock up. Use the rest for down, you will use it all.

Slight hyjack
I threw some 14" travel shocks on with Ford towers. Don't have the ability to flex it before hand, so just took a guess. I have 6" up and 8" down, but it's only on a 4" TC spring with zero rate. Until I can flex it, I'm just hoping it's plenty of travel. Opinions?