I'm in the process of putting my new 14 bolt under my K5 and have been looking at the shock mount and the differences between this and the ones on the 10 bolt I'm pulling out. I think the mount on the 14 bolt is too low to reuse my shocks, so I'm going to cut them off and modify as needed. This lead me to a question that I don't have an answer to:
Do the lower shock mounts have to be below the axle tube? Is there some stability or geometry reason for it or is that just the easiest was to get a little more stroke out of the system? Given how I'm going about my build, I'd be fine sacrificing an little stroke on the shock for the extra ground clearance. Is there a reason not to as long as I keep my shock at close to the same angle it already was?
I'm in the process of putting my new 14 bolt under my K5 and have been looking at the shock mount and the differences between this and the ones on the 10 bolt I'm pulling out. I think the mount on the 14 bolt is too low to reuse my shocks, so I'm going to cut them off and modify as needed. This lead me to a question that I don't have an answer to:
Do the lower shock mounts have to be below the axle tube? Is there some stability or geometry reason for it or is that just the easiest was to get a little more stroke out of the system? Given how I'm going about my build, I'd be fine sacrificing an little stroke on the shock for the extra ground clearance. Is there a reason not to as long as I keep my shock at close to the same angle it already was?
They don’t have to mount below the axle tubes, however to get decent travel without having the top of the shock riding in the cab with you they might have to hang down. There are other ways like DIY4x inboard shock kit. Or get creative with how you mount them. Keep in mind if you’re going to lean the shock over at any angle run a gas or nitrogen charged shock or you’ll lose a lot of dampening ability the more you lean a shock.
I ran my shocks on top of the axle tubes for ground clearance for years. I never noticed any abnormal performance because of it. Can’t comment on geometry though.
They don’t have to mount below the axle tubes, however to get decent travel without having the top of the shock riding in the cab with you they might have to hang down. There are other ways like DIY4x inboard shock kit. Or get creative with how you mount them. Keep in mind if you’re going to lean the shock over at any angle run a gas or nitrogen charged shock or you’ll lose a lot of dampening ability the more you lean a shock.
I'm really only looking at losing ~2" to get the mount level with the bottom of the tube instead of hanging below and I'm running big tires on not much lift, so my up-travel is going to be pretty limited either way. I've looked at the DIY4x inboarding kit, but to be honest there's some things about it I don't understand yet so I'm going to do more research before I commit to something like that. Shock mounts only cost me time and some scrap metal. I'm still new at this whole fabrication thing and trying to learn.
I'm really only looking at losing ~2" to get the mount level with the bottom of the tube instead of hanging below and I'm running big tires on not much lift, so my up-travel is going to be pretty limited either way. I've looked at the DIY4x inboarding kit, but to be honest there's some things about it I don't understand yet so I'm going to do more research before I commit to something like that. Shock mounts only cost me time and some scrap metal. I'm still new at this whole fabrication thing and trying to learn.
What do you have questions about? I’m not the all knowing, but there are a bunch of really fart smellers on this forum that I’m sure will chime in. I’m debating on doing a cantilever rear shock setup on my k5 just to troll a local shop. No clue really how to do it but plenty of info out on them for me to figure it out.
Yep, it's all about geometry and mounting convenience. You have a shock of a certain length, so usually to get the stroke you need without bottoming out the shock body, you would either have to move the upper mount into an inconveniently high spot in the cabin, or drop the mounts on the axle tube. That's the first reason the stock mounts are located where they are.
In terms of geometry versus mounting location, the dropped mounts on the axle tube are slightly better, as the shock will move in a smaller arc (with the axle travel) than if the mounts were in a higher location. That will keep the damping more linear with travel, but that's the only advantage. That's the other reason that the stock mounts are located where they are. There's no reason not to move the mounts if you need something different obviously, you'll just make things slightly less ideal.
You don't necessarily need anything as fancy as that inboarding kit; there are other options that are simpler if that's the issue. Often it's as simple as relocating the mounts with some type of gusseted mount/tower/whatever, and then making a bumped-up cover to closeout the clearance hole you would have likely needed to make in the body. The inboarding kit has nice adjustments and all that stuff, but it's not the only solution depending on your actual needs.
What do you have questions about? I’m not the all knowing, but there are a bunch of really fart smellers on this forum that I’m sure will chime in. I’m debating on doing a cantilever rear shock setup on my k5 just to troll a local shop. No clue really how to do it but plenty of info out on them for me to figure it out.
I appreciate that. Even though I'm in the wrong Carolina, the guys on this forum have been super helpful since I got into this hobby.
With the shock inboarding it's really just I don't have a firm grasp on all of the downsides. I know angling the shock decreases effectiveness and puts more side load on the pistons and seals, but not sure what else it causes with how the axle moves during articulation. Suspension travel and geometry has a little bit of black magic in it that I haven't wrapped my head around just yet. I'm a mech engineer by trade, so I can build the best damn shock mount scrap metal can make, but I'm still learning what's actually important to make my rig handle the way I want and be capable of what I want. My reason for asking about the mount going under the axle is I didn't know if it was done that way for some stability/axle wrap/handling reason or just to compensate for the length of the body of the shock.
I appreciate that. Even though I'm in the wrong Carolina, the guys on this forum have been super helpful since I got into this hobby.
With the shock inboarding it's really just I don't have a firm grasp on all of the downsides. I know angling the shock decreases effectiveness and puts more side load on the pistons and seals, but not sure what else it causes with how the axle moves during articulation. Suspension travel and geometry has a little bit of black magic in it that I haven't wrapped my head around just yet. I'm a mech engineer by trade, so I can build the best damn shock mount scrap metal can make, but I'm still learning what's actually important to make my rig handle the way I want and be capable of what I want. My reason for asking about the mount going under the axle is I didn't know if it was done that way for some stability/axle wrap/handling reason or just to compensate for the length of the body of the shock.
Okay well, this is something I’ve debated and experimented with a good bit between my Jeep and deciding to outboard the rear shocks. Personally I don’t like inboarding because it does allow the rear to not be dampened enough. I’ve got friends that run a gas charged shock outback and they swear by it but watching videos of their rigs they got the pogo affect going on. Which arises my concerns with doing the cantilever rear shocks on my k5. I don’t think they will be as affective as out boarding and running the shock as close to the backing plates as I can, while allowing me to remove brake components. You can get a shit ton more travel running inboarded shocks, but you’re gonna have to valve them like you would a cantilever shock because the motion ratio, I think that’s how it’s referred to it.
The shock should be used for 1 thing, in my opinion, dampen the spring. Not used for anti-wrap purposes, I bought some long ass spring perches to handle that, but may use a traction bar as well.
Edit: When I outboarded the shocks on my JK, it was better than a sway bar out back with the stock shock setup. It made me a believer in outboarding them, but I don’t want to put holes in the bottom of my k5 yet.
I appreciate that. Even though I'm in the wrong Carolina, the guys on this forum have been super helpful since I got into this hobby.
With the shock inboarding it's really just I don't have a firm grasp on all of the downsides. I know angling the shock decreases effectiveness and puts more side load on the pistons and seals, but not sure what else it causes with how the axle moves during articulation. Suspension travel and geometry has a little bit of black magic in it that I haven't wrapped my head around just yet. I'm a mech engineer by trade, so I can build the best damn shock mount scrap metal can make, but I'm still learning what's actually important to make my rig handle the way I want and be capable of what I want. My reason for asking about the mount going under the axle is I didn't know if it was done that way for some stability/axle wrap/handling reason or just to compensate for the length of the body of the shock.
It does decrease effectiveness, as it travels an different arc, and not all the linear motion goes into the shock (some of that motion just rotates the shock about that arc).
The extra side load thing... isn't a thing. If you have a shock with eyes on both ends (a pin joint on both ends, from your MechE classes), there is no more bending load when installed at an angle than what the shock sees when installed in a straight line. The angle just makes the shock rotate more about the eyes, and have less linear motion along the shock axis. The linear motion (along the shock axis) is what causes bending and side load. You're an MechE; think about it in terms of an X vector, a Y vector, and a resultant vector.
That inboarding kit puts the shocks at a pretty severe angle. This is fine for high amounts of one-wheel travel when offroad, but really sucks when trying to damp the axle on the street (in two-wheel bump/rebound). You can relocate the shock mounts with a different angle, depending on what your actual needs are (mostly street, mostly offroad, some combination of that).
The extra side load thing... isn't a thing. If you have a shock with eyes on both ends (a pin joint on both ends, from your MechE classes), there is no more bending load when installed at an angle than what the shock sees when installed in a straight line. The angle just makes the shock rotate more about the eyes, and have less linear motion along the shock axis. The linear motion (along the shock axis) is what causes bending and side load. You're an MechE; think about it in terms of an X vector, a Y vector, and a resultant vector.
That's the problem with classes, they teach physics in a perfect frictionless vacuum. Doesn't work that way when you introduce friction and shock loading. I'll admit, if everything is set up right, there probably won't be any noticeable difference, but I work with air and hydraulic cylinders a lot at work, and you'd be shocked at how much being just a little side loaded can affect the seals and make things want to bind.
There is one mounted in front and one behind. I've heard that is done very much on purpose so I'm going to leave it that way. I've got Bilstein 5100's so nowhere close to as fancy as a tunable shock.
I appreciate all of you guys' offers to help, I'm pretty sure I'm going to have some more questions come up as I go so I'll definitely be back to ask a bunch of ignorant noob questions.
The extra side load thing... isn't a thing. If you have a shock with eyes on both ends (a pin joint on both ends, from your MechE classes), there is no more bending load when installed at an angle than what the shock sees when installed in a straight line. The angle just makes the shock rotate more about the eyes, and have less linear motion along the shock axis. The linear motion (along the shock axis) is what causes bending and side load. You're an MechE; think about it in terms of an X vector, a Y vector, and a resultant vector.
That's the problem with classes, they teach physics in a perfect frictionless vacuum. Doesn't work that way when you introduce friction and shock loading. I'll admit, if everything is set up right, there probably won't be any noticeable difference, but I work with air and hydraulic cylinders a lot at work, and you'd be shocked at how much being just a little side loaded can affect the seals and make things want to bind.
I'm just curious about how you're planning on introducing a bunch more side load on the shock axis just by changing the shock mounting angle laterally (unless you're binding up bushings in torsion at the mounting points). If you're binding up the same shocks when you change the mounting angle, you've done something wrong with the new mounts and are introducing loads that shouldn't be there and obviously weren't there before, by creating a motion limiting problem that wasn't there before. The mounts obviously have to match the mounting angle of the shocks.
Dunno, everything I deal with has sphericals so we don't worry about side loading that already isn't introduced as bending forces from axial loads. If you're binding up sphericals, you've got a different problem to fix.
Bending loads from gravity (from moments about the mounting points from the shock weight and length) at whatever mounting angle are pretty small compared to the axial damping loads. If it wasn't, we couldn't run a damper horizontally with a bellcrank.
Basically, if you design a damper such that it doesn't bind up in bending under the axial loads in compression, it's not going to care about a little more load from gravity.
Unless you have really long, really heavy shocks, and then gravity may create some problems..
I'm just curious about how you're planning on introducing a bunch more side load on the shock axis just by changing the shock mounting angle laterally (unless you're binding up bushings in torsion at the mounting points). If you're binding up the same shocks when you change the mounting angle, you've done something wrong with the new mounts and are introducing loads that shouldn't be there and obviously weren't there before, by creating a motion limiting problem that wasn't there before. The mounts obviously have to match the mounting angle of the shocks.
Dunno, everything I deal with has sphericals so we don't worry about side loading that already isn't introduced as bending forces from axial loads. If you're binding up sphericals, you've got a different problem to fix.
One of the biggest issues that jumps out is the fact that on leaf springs the axle moves forward and backward as the suspension flexes. This isn't an issue in the stock configuration because that's the direction the bolts rotate. When you inboard you rotate the mounting bolts 90 degrees. In theory the rubber bushings make up for the movement, but in reality some of it gets transferred to the cylinder, particularly as the piston nears full extension. Stop tubes help prevent that from happening when you have to extra space for the housing, but that's not very practical in most vehicles where space is at a premium.
Again, I'm used to industrial applications where there's a lot of force and/or a lot of full strokes occurring. I don't have any experience transferring that knowledge into vehicle shocks.
One of the biggest issues that jumps out is the fact that on leaf springs the axle moves forward and backward as the suspension flexes. This isn't an issue in the stock configuration because that's the direction the bolts rotate. When you inboard you rotate the mounting bolts 90 degrees. In theory the rubber bushings make up for the movement, but in reality some of it gets transferred to the cylinder, particularly as the piston nears full extension.
You're saying that there is no side load in the stock configuration during heave and pitch (when the axle travels vertically and stays parallel to the chassis plane) because of the bolt direction, and because the upper and lower bolts are more or less parallel. This is true.
But....
What about chassis roll (or one-wheel axle bump/droop) in the stock configuration, where the chassis plane and axle move at angles to each other? Then what happens to the bolt direction?
You're saying that there is no side load in the stock configuration during heave and pitch (when the axle travels vertically and stays parallel to the chassis plane) because of the bolt direction, and because the upper and lower bolts are more or less parallel. This is true.
But....
What about chassis roll (or one-wheel axle bump/droop) in the stock configuration, where the chassis plane and axle move at angles to each other? Then what happens to the bolt direction?
It still sounds like you're just going to change the stock mount locations to suit the new axle, and aren't going to do something more extreme like an inboard setup, correct?
If you're just doing mild changes to mate the chassis and axle (as in the original post), I would trust your intuition about the mounts and go have some fab fun.
It still sounds like you're just going to change the stock mount locations to suit the new axle, and aren't going to do something more extreme like an inboard setup, correct?
If you're just doing mild changes to mate the chassis and axle (as in the original post), I would trust your intuition about the mounts and go have some fab fun.
Yea, that's all I'm planning on, just wanted to make sure there wasn't some more complicated reasoning for how it's done that I wasn't aware of. We may have gotten a little carried away there for a little bit.
Basically I'm going to move the lower mounting points up so that they don't impede on ground clearance so much and I don't have to buy new shocks.
