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CK5
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'72 K5 - Greg's @MightAsWellK5 Build
- Thread starter Greg72
- Start date
This is the build description. I will improve this later. (GB)
or 261 for some of us.
You ever just think "uggg. what the heck am I doing"
You ever just think "uggg. what the heck am I doing"
You ever just think "uggg. what the heck am I doing"
Yes I do.
The truth is that there are a few dozen things that have to be managed simultaneously to be successful at this. Each time a change gets made it's important to run through the list and make sure that there are no unintended consequences...
The latest strategy that seems to be working well for this build is to spend basically one full weekend day on it, then spend about 4 - 5 hours each night (Monday - Wednesday) as well. This allows for progress, but also allows for an important "reflection period" between each visit to the workshop. During that time my mind is still fresh enough about the build and details that it's possible to work out solutions and come up with creative ways to deal with issues. Knowing that I can get into the shop a few days in a row really improves the efficiency of things, and the thought process stays fresh...
Believe it or not, the front suspension IS getting closer to completion. A lot of parts are still moving around by an inch or two here and there... but most of them are now "fine tuned" in terms of where their final positions will ultimately be. Going back to the Excel spreadsheet and plugging in the "AS BUILT" values that are on the truck now was a big confidence builder as well. There are no glaring issues with the current link positions, and typically if it looks good on paper it will typically work well in real-life too.
-G
Here's a graphic example that shows how the "refinement" process is actually going.....
The light green cells are "AS BUILT" values measured on the truck this past weekend.
The light orange cells are values where some additional changes could be made to improve things...
As you can see, there are only a few orange cells left to mess with.
The upper link was 31.25" long (as measured on truck) but it turns out that it can be quite a bit shorter than that (new target is 25.25") with no appreciable changes to the front geometry. Moving the frame-side mount forward will improve footwell space on the passenger side!
My roll axis ended up at about -4.5* (roll understeer) which was actually a little too much of a good thing. As both Brandon and Eric suggested, it is now possible to push my converged lower links outward a bit more (16" apart instead of 6" apart) and dial that roll axis to a more reasonable -2.14*
Overall pinion change from full bump to full droop is quite good....less than 5* throughout the entire 14" of travel. That should be pretty easy on the u-joints and I wouldn't expect them to bind at all even at the extreme ends of the suspension travel.
Tonight if things go well, maybe there will be a chance to change a few of those orange cells to green and "lock down" a few more dimension permanently?
-G
The light green cells are "AS BUILT" values measured on the truck this past weekend.
The light orange cells are values where some additional changes could be made to improve things...
As you can see, there are only a few orange cells left to mess with.
The upper link was 31.25" long (as measured on truck) but it turns out that it can be quite a bit shorter than that (new target is 25.25") with no appreciable changes to the front geometry. Moving the frame-side mount forward will improve footwell space on the passenger side!
My roll axis ended up at about -4.5* (roll understeer) which was actually a little too much of a good thing. As both Brandon and Eric suggested, it is now possible to push my converged lower links outward a bit more (16" apart instead of 6" apart) and dial that roll axis to a more reasonable -2.14*
Overall pinion change from full bump to full droop is quite good....less than 5* throughout the entire 14" of travel. That should be pretty easy on the u-joints and I wouldn't expect them to bind at all even at the extreme ends of the suspension travel.
Tonight if things go well, maybe there will be a chance to change a few of those orange cells to green and "lock down" a few more dimension permanently?
-G
TheBeast_88K5
Banned
Can I just say.... This feels like a "F*ck yea!" Moment.
A few nice little bits of progress last night.....
Squared-up the steering arms with a couple of large framing squares and 1x2" tubing, then tacked a second precisely-cut 1x2" tube between them to hold that dimension perfectly while I work on the new steering arm fabrication and tie rod length.
Worked great!
Checked a few of my "orange cell" values and it looks like those changes can be made on the actual truck without issue.
The new discovery was that the PHB current angle is 2.4*... Pretty close to level at ride height.
I'm debating whether it's worth the effort to mess around with the axle and frame mounts (roughly a 2" change overall) to get the PHB and draglink 100% level at ride height.
-G
Squared-up the steering arms with a couple of large framing squares and 1x2" tubing, then tacked a second precisely-cut 1x2" tube between them to hold that dimension perfectly while I work on the new steering arm fabrication and tie rod length.
Worked great!
Checked a few of my "orange cell" values and it looks like those changes can be made on the actual truck without issue.
The new discovery was that the PHB current angle is 2.4*... Pretty close to level at ride height.
I'm debating whether it's worth the effort to mess around with the axle and frame mounts (roughly a 2" change overall) to get the PHB and draglink 100% level at ride height.
-G
TheBeast_88K5
Banned
This is turning into quite the engineering task....
Which you appear to be handling quite well...
Which you appear to be handling quite well...
I'm debating whether it's worth the effort to mess around with the axle and frame mounts (roughly a 2" change overall) to get the PHB and draglink 100% level at ride height.
-G
No its simply not. That change will not have a significant effect on anything really.
Thanks Eric!
I was afraid that I'd scared you away from this thread somehow....Unfortunately, my little boy got sick.....then a couple days later my lovely bride got sick. So I knew what was coming next. I felt like crap last night, but didn't want to miss my chance to use some of my new 1/4" plate and cut up some new heim tabs. I checked and double-checked my math and then cut a set of lower mounts for the tierod heims.
The end result wasn't too bad. As mentioned in an earlier post, the exact value for the tierod length depends on the exact value of the tierod in the vertical axis. My estimate was that it was 1/2 way between the upper and lower KPs which turned out to be pretty close. When the wheels were turned to the stops, the tierod appeared to be too short (again) by a total of 3/4".... so basically, by moving the holes 3/8" per side and adding 3/4" to the tie rod length things SHOULD have been perfect.
I said SHOULD...
What I wasn't counting on was a collision between the tierod and the front of the pumpkin when turning hard right. Unlike parallel steering, with Ackerman the tie rod ends up VERY non-parallel to the axletube at the extreme ends of the steering swing....and since the pumpkin is pushed hard to the PS, that's where the issue showed up.
Initially I toyed with the idea of raising the tierod (with spacers) to go over the hump in the pumpkin and allow me to reuse my existing holes, but there isn't much space available before the tierod/draglink heims start interfering with the PHB on the passenger side.
My decision was to extend the length of the steering arms (from 8.0" to 8.75") and create more pumpkin clearance that way.... Of course, moving the tierod forward meant that the tierod needed to get even LONGER since Ackerman steering requires the tierod to get longer as you move further ahead of the kingpins.
Not a bad nights progress considering that I was only feeling about 70% health wise.
-G
Some photos to illustrate my previous comments...
The first tie rod position of the evening. This is the 8" overall steering arm length position with a 49.5" tie rod (heim center to heim center)
That setup would not move all the way to the steering stops, so I unbolted one side of the tie rod to see why.... this mark was scribed through the center hole of the heim to show where the heim "wanted" to be with both knuckles against the steering stops....
The difference is 3/4" total, so if that was split between the two sides the holes needed to move 3/8" each to make the tierod longer. Unfortunately, this is when I also discovered that the tie rod was hitting the pumpkin (even without full lock-to-lock steering) so changing the hole spacing wasn't going to make any difference unless I also moved the tie rod further away from the pumpkin...
This is the next iteration of the mounting hole.... the overall steering arm pivot length was increased from 8" to 8-3/4" (moved toward front of truck) and the holes were also pushed outward (toward the wheels) by about 1/2" as a starting point.
Unfortunately, at this point I ran out of threads in my tie rod and couldn't lengthen the rod anymore without the heims falling completely out. At the maximum length I could achieve (with maybe 2 threads catching on either side) the knuckles were still about 3/8" from hitting the steering stops but the photo shows that the tierod is already starting to angle inward quite a bit on the PS (as expected with Ackerman steering)
This is a shot from directly underneath that might show it a little better...
So basically at this point, it seems like the 8-3/4" steering arm length will probably work and clear the pumpkin, but I'll need to make up a new longer tierod to test it 100%. Also, I'll need to run that same experiment where I pull one heim out of the tab and see if the steering gets tighter or not. That will be the last step to confirm that the holes are in the perfect spot in both axies (x and y)... and from there I can move forward and make up a fresh set of mounting tabs to complete both arms and get the draglink bolted back up.
-G
The first tie rod position of the evening. This is the 8" overall steering arm length position with a 49.5" tie rod (heim center to heim center)
That setup would not move all the way to the steering stops, so I unbolted one side of the tie rod to see why.... this mark was scribed through the center hole of the heim to show where the heim "wanted" to be with both knuckles against the steering stops....
The difference is 3/4" total, so if that was split between the two sides the holes needed to move 3/8" each to make the tierod longer. Unfortunately, this is when I also discovered that the tie rod was hitting the pumpkin (even without full lock-to-lock steering) so changing the hole spacing wasn't going to make any difference unless I also moved the tie rod further away from the pumpkin...
This is the next iteration of the mounting hole.... the overall steering arm pivot length was increased from 8" to 8-3/4" (moved toward front of truck) and the holes were also pushed outward (toward the wheels) by about 1/2" as a starting point.
Unfortunately, at this point I ran out of threads in my tie rod and couldn't lengthen the rod anymore without the heims falling completely out. At the maximum length I could achieve (with maybe 2 threads catching on either side) the knuckles were still about 3/8" from hitting the steering stops but the photo shows that the tierod is already starting to angle inward quite a bit on the PS (as expected with Ackerman steering)
This is a shot from directly underneath that might show it a little better...
So basically at this point, it seems like the 8-3/4" steering arm length will probably work and clear the pumpkin, but I'll need to make up a new longer tierod to test it 100%. Also, I'll need to run that same experiment where I pull one heim out of the tab and see if the steering gets tighter or not. That will be the last step to confirm that the holes are in the perfect spot in both axies (x and y)... and from there I can move forward and make up a fresh set of mounting tabs to complete both arms and get the draglink bolted back up.
-G
2013.08.02 - UPDATE! - AWESOME AUGUST ACKERMAN...
DONE! Finally.....
Built a new longer tie rod and a couple of new mounting tabs and with the new longer steering arm hole spacing (8-3/4") the steering cycles hard left to hard right with no interferences with the pumpkin. Thank goodness.... Now it's finally time to move along to something else.
Here's a fun little experiment that I've been researching and working on the the background
A 17x9" wheel with a factory 12" hubcap!
Looks a lot better to me than the H2 wheels....
-G
DONE! Finally.....
Built a new longer tie rod and a couple of new mounting tabs and with the new longer steering arm hole spacing (8-3/4") the steering cycles hard left to hard right with no interferences with the pumpkin. Thank goodness.... Now it's finally time to move along to something else.
Here's a fun little experiment that I've been researching and working on the the background
A 17x9" wheel with a factory 12" hubcap!
Looks a lot better to me than the H2 wheels....
-G
Hey man I am in the hub cap crowd I dig em. Only thing better on your rig would be some 17x9 rallyes with chrome rings on em
Steering looks good, that should help alot when you are crawling the mall and stuff
Steering looks good, that should help alot when you are crawling the mall and stuff
Hub caps!!!!
You know the way to my heart!
Martin
Martin
y5mgisi
1 ton status
Everything is perfect as usual! I wish i had your way of building.
hell, I'd settle for just having everything as clean as that!
I'm sure you already took this into account... make sure when testing clearance, you rotate your PHB back and forth. Now that you put a bend into it, it can rotate front to back a little. I ran into this issue when I bent my PHB for clearance on the ORD link kit. Luckily, one of the local road race guys had a solution for me and it was these rubber "bushings" that you put on either side of the heim (frame side). Look at my ORD Link thread, and you can see them inside of the PHB bracket.
Great build and progress!!!
Great build and progress!!!
boonedog
Registered Member
Glad you got it figured out. I dig the wheels and caps
Looks a lot better to me than H2 wheels....
anything does
I do sorta like h2's painted black for some reason though
2013.08.07 - UPDATE! - LOTS OF PRETTY BRACKETS!
Yep.
I've reached that point in the front suspension build where the ugly "placeholder" brackets need to make way for the actual, beefy mounts in their final positions. Things will still be "tacked" together just in case there are some last-minute changes that need to be made, but at this point it's just time to man up and commit to the final parts.
I've made a couple of days worth of progress without an update, so I'll give some background on what's been going on in the shop. As mentioned before, I've been carefully studying my 3-Link Calculator design and trying to confirm all of the dimensions for each of the links (x,y & z coordinate space) so that the diagram will accurately reflect what has been built in my garage. The garage floor is sloped toward the rollup doors (like most are) so it's not always easy to get an accurate z-axis measurement....the further you move away from the axle centerline (toward the back of the truck) the more the slope of the cement screws up the "actual" values you want to measure. (This explains why in some photos you can see my rear tires are actually sitting on almost 4" of scrap lumber to level the truck vs. the sloping cement!) Sometimes it's not all that easy to get accurate (x,y) coordinates either since there always seems to be something in the way of a straight tapemeasure mark, so it made sense to lay down some rosen paper and drop all of my dimensions with plumbbobs to really see what was going on....
I was able to get accurate positioning of the axletube, axletube centerlines (both in x and y-coordinate space) and all of the link positions. In most cases they were VERY close to what was on the spreadsheet, but not quite perfect. In fact, the entire axle was about 1/4" shifted toward the PS at ride height, so it was good that I found that before locking down all of the PHB bracketry. Obviously, I could have changed the length of the PHB to compensate, but I'm trying to hold the draglink and PHB at 41" (each) since it's been working well so far.... no need to add more variables before the next "cycling day" happens!
On the subject of locking-down dimensions, it was time to replace the multi-hole PHB bracket on the DS frame area with a "real" part at 32.75" hole center. The axle-side mounting hole is at 30.75" for an overall PHB angle of 2.8* The draglink bracketry will need to be built to provide this same angle as well.
NOTE: The photo is a bit of an optical illusion. The PHB bracket appears to be directly over the top of the axletube but it is well-forward of that location so that it clears on bump travel. Also, the 1x2 square tube in the foreground is my "squaring bar" for the front wheels. This gets wedged between the steering arm plates and keeps them both pointing 100% forward and parallel. It was very helpful to have in there when I was doing my tie rod/ Ackerman experiments.
With the frame-side mount completed, it was time to focus attention on replacing the ugly axle-side PHB mount.
This one wasn't going to be easy.... it is really hanging "way out there" in space, not really close to any obvious anchoring points. For the early mockups since I was only hanging the heim from one side, the difficulty of creating a double-shear mount wasn't immeditely appreciated. Now that the mount needs to hold the heim from both sides and support the massive lateral forces that it will actually see, the game has changed substantially...
The idea was to build a flat base plate that would anchor to a number of spots (the inner "C" mounting plate, across the bumpformed housing of the axle, and also the existing upper link mount brackets) This would lock the PHB in pretty tightly to that area and would have the side benefit of providing a nice flat area to build the lower strut mount bracket on also.
Here's an early cardboard template of the idea:
After a bit of test fitting, the part was cut from 1/4" plate and carefully trinmmed down and test fitted (about 1000 times!) until it had a nice precise fitment into the space. Then it was time to build the mounting tabs that would hold the heim at the correct height (30.75").
On the bench:
Here's the early test fitting with the first heim tab tacked into place...
Another shot showing both mounting tabs in place and starting to tie-in to the surrounding axle components...
This is how it sits as of now.... I can probably cut off that PHB brace from the frame now that the acutal bracket is far enough along. There is quite a bit of additional bracing that needs to take place underneath this PHB plate to strengthen it further and tie it in more completely to the pumpkin and upper link mount brackets. That will come next.
Maybe tonight?
-G
Yep.
I've reached that point in the front suspension build where the ugly "placeholder" brackets need to make way for the actual, beefy mounts in their final positions. Things will still be "tacked" together just in case there are some last-minute changes that need to be made, but at this point it's just time to man up and commit to the final parts.
I've made a couple of days worth of progress without an update, so I'll give some background on what's been going on in the shop. As mentioned before, I've been carefully studying my 3-Link Calculator design and trying to confirm all of the dimensions for each of the links (x,y & z coordinate space) so that the diagram will accurately reflect what has been built in my garage. The garage floor is sloped toward the rollup doors (like most are) so it's not always easy to get an accurate z-axis measurement....the further you move away from the axle centerline (toward the back of the truck) the more the slope of the cement screws up the "actual" values you want to measure. (This explains why in some photos you can see my rear tires are actually sitting on almost 4" of scrap lumber to level the truck vs. the sloping cement!) Sometimes it's not all that easy to get accurate (x,y) coordinates either since there always seems to be something in the way of a straight tapemeasure mark, so it made sense to lay down some rosen paper and drop all of my dimensions with plumbbobs to really see what was going on....
I was able to get accurate positioning of the axletube, axletube centerlines (both in x and y-coordinate space) and all of the link positions. In most cases they were VERY close to what was on the spreadsheet, but not quite perfect. In fact, the entire axle was about 1/4" shifted toward the PS at ride height, so it was good that I found that before locking down all of the PHB bracketry. Obviously, I could have changed the length of the PHB to compensate, but I'm trying to hold the draglink and PHB at 41" (each) since it's been working well so far.... no need to add more variables before the next "cycling day" happens!
On the subject of locking-down dimensions, it was time to replace the multi-hole PHB bracket on the DS frame area with a "real" part at 32.75" hole center. The axle-side mounting hole is at 30.75" for an overall PHB angle of 2.8* The draglink bracketry will need to be built to provide this same angle as well.
NOTE: The photo is a bit of an optical illusion. The PHB bracket appears to be directly over the top of the axletube but it is well-forward of that location so that it clears on bump travel. Also, the 1x2 square tube in the foreground is my "squaring bar" for the front wheels. This gets wedged between the steering arm plates and keeps them both pointing 100% forward and parallel. It was very helpful to have in there when I was doing my tie rod/ Ackerman experiments.
With the frame-side mount completed, it was time to focus attention on replacing the ugly axle-side PHB mount.
This one wasn't going to be easy.... it is really hanging "way out there" in space, not really close to any obvious anchoring points. For the early mockups since I was only hanging the heim from one side, the difficulty of creating a double-shear mount wasn't immeditely appreciated. Now that the mount needs to hold the heim from both sides and support the massive lateral forces that it will actually see, the game has changed substantially...
The idea was to build a flat base plate that would anchor to a number of spots (the inner "C" mounting plate, across the bumpformed housing of the axle, and also the existing upper link mount brackets) This would lock the PHB in pretty tightly to that area and would have the side benefit of providing a nice flat area to build the lower strut mount bracket on also.
Here's an early cardboard template of the idea:
After a bit of test fitting, the part was cut from 1/4" plate and carefully trinmmed down and test fitted (about 1000 times!) until it had a nice precise fitment into the space. Then it was time to build the mounting tabs that would hold the heim at the correct height (30.75").
On the bench:
Here's the early test fitting with the first heim tab tacked into place...
Another shot showing both mounting tabs in place and starting to tie-in to the surrounding axle components...
This is how it sits as of now.... I can probably cut off that PHB brace from the frame now that the acutal bracket is far enough along. There is quite a bit of additional bracing that needs to take place underneath this PHB plate to strengthen it further and tie it in more completely to the pumpkin and upper link mount brackets. That will come next.
Maybe tonight?
-G
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