Sandbox2.000 Suspension Build

[97Sandbox]

Hey y'all! I know there have been a few good coilover swap threads, but I'm going ahead and starting one to document my journey.

From what I've seen, many folks go for coils as a way to achieve the same lift as a torsion twist but improve ride quality instead of reduce it. While I am after improved ride quality, I'm also looking to lower the center of gravity of my Sport, which is where adjustable coilovers come in. This thread will encompass all I have planned and likely more! This includes:
- Front end coilover conversion (starting out with 600 lb springs)
- Swapping mono-leaf springs for 1250 lb leaf packs
- Polyurethane bushings throughout (UCAs, LCAs, leaf springs, shackles, sway bars, etc.)
- Sway bar upgrades
- Lowering 2-3 inches

This may take me a while, but I wanted to kick things off because I came home to some exciting packages this evening and just had to share!

 

[CDW6212R]

Pave the way, and I hope it goes smoothly for you. I plan to do my front suspension last, and also as a lowered Explorer. I'm curious about the spring rate, for a lowered truck they made need to be shorter. But I'd expect the rates to be similar but a little less than lifted trucks. So you are in uncharted territory I think.

 

[97Sandbox]

Pave the way, and I hope it goes smoothly for you. I plan to do my front suspension last, and also as a lowered Explorer. I'm curious about the spring rate, for a lowered truck they made need to be shorter. But I'd expect the rates to be similar but a little less than lifted trucks. So you are in uncharted territory I think.

You may be right about this being uncharted for Explorers, but the setup I'm planning actually came recommended by the Ranger-Forums member who made the coilover conversion kits. Supposedly he used these Strange coilovers on a few lowered Rangers.

From what I've read, the lifted trucks do well with 650-800 lb springs and the lowered trucks are better in the 500-600 range.

I'll be looking forward to getting a setup installed and dialed in to report back to you all!

 

[CDW6212R]

I look forward to your results. I have high hopes the ride improves noticeably. I've explored all of the lowering and suspension upgrades, the big sway bars and urethane mounts. Improving the normal ride is a great goal to aim for.

 

[97Sandbox]

I put in some serious work this weekend getting the D4 rear end off my '97 XLT and swapping the 3.27 open rear end from the '00 in its place. Currently spiffing up the '97 rear end before I install it on the '00.

Looking ahead, I will be mounting the better axle assembly along with the heavier leaf packs from my four door onto the '00. Since it's all apart, it seems like a good time to reassemble everything with the lowering blocks and pinon shims in place.

I noticed the Belltech blocks I bought don't quite fit over the center bolt heads of the leaf springs -- is it okay to drill partway into the blocks to make room? I figure most of the load is carried on the perimeter edge of the blocks, but surely drilling will lead to some reduction in strength...

Similarly, I noticed that the Belltech pinion shims I bought will almost entirely take up the height of the "bumps" on the lowering blocks. This won't leave much for the axle to lock into. Anyone else running pinion shims have a suggestion?

Thanks for any help!

 

[97Sandbox]

I did a little more reading about sport truck rear suspensions and it seems to me that it's not uncommon to have to drill into lowering blocks.

When using pinion shims, the best option appears to be to drill completely through each block (removing the bumps) and run a longer center bolt through both the block and the leaf pack. This allows you to add a spacer under the head of the center bolt (on top of the block), which "lifts" the bolt head above the shim so it can nest into the hole on the axle. Alternatively, there are some center bolts which simply have a taller head.

...sounds like I need some long bolts and/or spacers!

 

[CDW6212R]

Thanks for your efforts. Not many people have posted about what they had to do to install various lowering blocks. My two pairs were shorter and the EE units were specifically made for the Explorer, with longer u-joints. So my stuff didn't have to have any extra work done to fit them properly.

So post anything that you learn, others will have similar issues and may find this thread.

 

[97Sandbox]

Thanks Don and will do!

On a related note, what solution did you come up with for your rear sway bar links once you installed lowering blocks? I seem to remember you mentioning adjustable links at one point, but can't remember the thread.

 

[Blown]

I built my own leaf packs a few times now with stock and added wrecking yard leaves, anyway I used a longer bolt of the correct diameter and had to grind the bolt heads round to fit into blocks, wedges and axle perches. I have used a tight fitting lock washer to raise the bolt head up enough to be a better pin. A cap head bolt has a round head and is taller. A cap head would likely work without grinding and without a spacer as they have a taller head.

 

[CDW6212R]

My truck I only lowered 2 3/8" with the EE X-spec kit, I didn't really have to change the sway bar end links. Ideally the end links should be the length needed to keep the sway bar level at ride height. If the height is changed a lot, then the end links place the bar at a more extreme angle, so a shorter end link is needed for a much lowered truck.

I had read of other similar trucks with different length rear end links, but didn't dig deep to locate a better one. There are a couple of choices, here's a great one by @swshawaii;

F250/350 SD 4WD rear end links (Moog K80268) are as perfect a fit as I could imagine. Offset and length seem perfect for ST's lowered 3 inches or 1995-01 Explorers lowered 1.5 to 2 inches. Remove all four of the stud bushings and use NAPA MRC18339, NCP2651543, or Moog K80085 thermoplastic rubber kits. I recently upgraded to the Energy Suspension 4.5153 polyurethane kit that includes 1.25" metal inner sleeves that are the correct length and difficult to find separately. Frame bushings are also included that are used with stock 19mm rear sway bars. Unlike hollow OEM end links these are solid rods and can be bent for adjustments if required, and tailpipe clearance is no longer an issue.A much stronger option to cutting and welding sleeves on the stock end links, and probably cheaper in the long run. Second pic is stock Sport Trac (K80788) top and stock 1995-01 Explorer (K80139) bottom.

Top K80788 Sport Trac- Center K80268 F250/350 SD 4WD - Bottom K80101 Ranger
View attachment 329553
Top K80788 / Bottom K80139
View attachment 329554

 

[97Sandbox]

I built my own leaf packs a few times now with stock and added wrecking yard leaves, anyway I used a longer bolt of the correct diameter and had to grind the bolt heads round to fit into blocks, wedges and axle perches. I have used a tight fitting lock washer to raise the bolt head up enough to be a better pin. A cap head bolt has a round head and is taller. A cap head would likely work without grinding and without a spacer as they have a taller head.

Awesome, thanks! That's the direction I'm thinking. I'm going to try to find a 6" or so cap head bolt, ideally with a taller head, but the lock washers don't sound like a bad solution either.

 

[97Sandbox]

My truck I only lowered 2 3/8" with the EE X-spec kit, I didn't really have to change the sway bar end links. Ideally the end links should be the length needed to keep the sway bar level at ride height. If the height is changed a lot, then the end links place the bar at a more extreme angle, so a shorter end link is needed for a much lowered truck.

I had read of other similar trucks with different length rear end links, but didn't dig deep to locate a better one. There are a couple of choices, here's a great one by @swshawaii;

Thanks! Checking RockAuto specs it looks like those F250 links are 1.6" shorter than the Explorer links and just about the right offset. Might not be perfect with my 3" drop, but they're headed in the right direction!

 

[97Sandbox]

After looking at several center bolt options, I went with the Dorman 03762. They're a standard 7/16" center bolt with a 5/8" round head (slotted) that's 3/8" tall. Based on my measurements, they'll work with the axle and the leaf pack. They're also 12" long, so you cut them to whatever size you need -- I'm guessing about 5.75" to pass through the 3" block, ~2" leaf pack, and have room for a couple washers on top and a nut on the bottom.

 

[97Sandbox]

I also wanted to share how I came up with my 4 deg pinion shims in case anyone wants to know. This may not be 100% "to-spec," but it made sense to me. Here goes...

 

[97Sandbox]

Assumptions:
- Vehicle sitting at ride height on level ground with undamaged, unloaded suspension
- Pinion gear is roughly parallel to ground with axle mounted to stock leaf springs
- The above assumptions (and lack of driveline vibration) lead me to believe the stock driveshaft/pinion angle is adequate

 

[97Sandbox]

Measurements:
I tied two lengths of string to nuts to make plumb bobs and tied each non-nut end to each u-joint. Let them hang as close to the ground as possible without touching.
- Dimension 1: Horizontal length of driveshaft (distance between hanging nuts) = 45" -- note: this will be different for a 4 door or 4x4 truck
- Dim. 2: Rear u-joint elevation: I forget, so call it "X"
- Dim. 3: Front u-joint elevation: call it "Y"

 

[97Sandbox]

The Math:
Don't get scared, it's addition and subtraction plus a bit of trig, but I'll explain that part

Imagine a right triangle and use trig to get the stock driveshaft angle at the pinion, call it theta:
- The side adjacent to theta is Dim. 1, so 45
- The side opposite theta is the difference between Y and X, Y - X = 5 in my case.

- Now theta is the inverse tangent of the opposite divided by the adjacent, theta = arctan(opposite/adjacent) = atan(5/45)*(180/PI()) = 6.34 deg
*If using Excel, the atan function yields an answer in radians, multiplying by 180/Pi gets you to degrees.
*If using a calculator, set to DEG mode and skip the unit conversion.

Next we redo the math based on how much you're lowering to find what the new driveline angle would be without a shim. This requires subtracting the block height from the original "opposite," 5 - 3 = 2 in my case with 3" blocks.
- Now trig it again! The new theta = atan(2/45)*(180/PI()) = 2.54 deg.

Since the new driveshaft angle is smaller (due to the pinion moving upwards relative to the transmission), we need to turn the pinion down to get the angles back into shape.

 

[97Sandbox]

 

[97Sandbox]

The Answer
While my solution is a bit of an oversimplification (doesn't totally address the angle at the transmission), I'm thinking it will be "good enough." I just subtracted the new theta from the original, 6.34-2.54=3.80. That 3.80 deg is the angle to be added back by installing the pinion shim. Since I wanted an off-the shelf shim, I rounded up to 4 deg and called it a day.

 

[97Sandbox]

Whew, that was a lot! Sorry I had to break it into so many posts, kept running into an error.

Feel free to point out any mistakes, tell me about better methods, or ask me questions about my logic.