2021 Ford F150 -> XTF pre runner build log

[Higgybulin]

What did you use to smooth the ends caps?

[kabacj]

What did you use to smooth the ends caps?

Hey Higgy,

I actually didn’t do any post processing of this print. It’s right off the printer.

I did consider using acetone vapor to smooth the surface, but semi melting the surface would likely make the part shiny and round the edges a bit. I wanted the sharper edges and the matte finish so I just pulled the part of the printer and installed it.

I did print with thin layers. I if I remember correctly I printed at 1/10 of a millimeter layers.

[Blitzboy54]

THANKS Crash!

Thats the type of experience I was looking for.

While I don't want to pay a high price, I know I will own this trailer for a long time. My 24 foot 10k enclosed race trailer has served me well. I’d like about that size in a goose neck as well. Hauling two trucks, even the XTF and a lighter shorter Jeep is going to be pushing the 26,000 lb weight combined GVW weight limit in NY.




Unfortunately getting a CDL in NY is a little annoying. It means signing up for a commercial drivers license training course that includes rental of the rig for taking the test. I wouldn't mind learning how to drive a Semi, however it’s a time investment.

It looks like getting a de rated goose neck might be my best bet. I can get a 16k trailer de rated to 14,000k which will keep me under the combined 26,000 lb GVW limit. It sounds like even if I have a heavier than 14,000 trailer empty , I could be ticketed because the combined rating is above the CDL limit.

Oh well. Seems that the DMV laws have not kept up with the capability of todays pickups.

This is correct. I had a CDL in Oregon, when I moved back to NY I surrendered it because it just wasn't worth the hassle or annual fees for a "just in case" license.

[kabacj]

This weekend I spent some time working through the unfinished items on the truck build. In my rush to get the truck ready for SEMA I was focusing on the things that needed to work vs the nice to have options.

The two items were the rear running lights and the backup lights in the bumper. I really hate cutting into the factory wiring harness. The workmanship is so high, these things will last many many years. As soon as you cut into them however they are typically worse. Since the tail lights are LED the wires are also very thin.

Since I am not towing, I decided to use the 8 pin trailer wiring harness and a trailer wire to plug into the factory electrical.



Lots of benefits doing it this way as the harness is fused and has plenty of capacity and I can just use the a trailer wiring kit and I am good to go with an already made system.

I have power wires for everything needed including the running lights, backup lights as well as my off road chase lights.



In my opinion it’s worth spending time on making the truck wiring bullet proof. Everything soldered, and wrapped with marine grade adhesive lined heat shrink tubing.

It does take lots of time.

But after a few hours of re routing the factory F150 harness and making up the extension harness I had light.

Here are the backup lights in the bumper. The kit backup lights are excellent.



And a dramatic smoky shot of the rear running lights

[Erik W. Treves]

Looks great - I still haven't wired up any of my lights in the back

[kabacj]

I am looking forward to some testing like this with my XTF!! That suspension travel and smooth ride over insane terrain is next level.

https://youtube.com/shorts/jBzkl-x-s...nIdNwzc4O1hihX

[kabacj]

Messy wiring bothers me.

In order to finish the SEMA build on time I needed to cut corners on the things that I could tidy up after the show.

Wires and hoses were simply zip tied in place.

The kit provides wire clamps like this to organize hoses and wires.



Since I’m still developing the truck I wanted a solution that was easily changed moved and modified. Something more finished looking than zip ties but just as easy to change. I also didn’t want to drill any holes in the frame that would show after I moved a fastener. I know very minor, but it’s a thing for me.

One cool thing about 3d printing is that it’s possible to make hollow parts. I needed a fastener that would locate the hose or wiring harness on the square tube as well as hold the wire or tube in position.

I came up with this design. Here is a cross section showing the hollow channel.




A zip tie holds the wire management part to the square tube as well as the wire loom



I printed off a bunch of them to manage the wire loom as it routes down the drivers side of the frame.



Here is a shot of the first sections of the main harness securely attached to the frame, but easily moved.



Time consuming work, but satisfying when all the wires neatly follow the frame and can be held out of harms way.

[kabacj]

Back in July I discovered another thing that ford changed between Gen 13 and Gen 14 F150s. The vapor canister. As you can imagine Ford goes through great lengths to ensure that fuel vapors dont vent into the atmosphere. Our problem is the shape and frame mounting points change between generations of the F150.

Here you can see how the canister tucks between the frame and transmission on the drivers side of the frame.



Here I have it clamped in place using the hardware and brackets that factory five provide that fit the Gen 13 F150.



I could sort of make it work maybe using a bunch of washers to adjust for the change in mounting angles between the frame and canister.

The rear mounts are pretty good I could make these work. Cutting and welding the factory five brackets was an option, but I don’t know if I want the canister to live in this spot.





Like the wiring, I didn’t have time to sort out an elegant solution to mount the canister so I just zip tied everything in place for SEMA.

Since I love having a robot make stuff for me …3d printing to the rescue.

I printed a bracket that captures the frame for the rear mount .



Then made a two part bracket for the front mount.



This shows the gold prototype I used to verify my part dimension's before a few tweaks then making a final print for installation.

Check off another problem solved by the 3d printer.

[kabacj]

As I work my way to the back of the truck tidying up all the wires I needed to move the electronics that control the fuel pump. The kit provides a plate to mount on to the frame Then I used that plate to attach this fuel pump controller housing to the frame.

When I removed the fuel pump controller box I saw that it was made to snap into place on the F150. Probably so as the truck can be quickly put together on the assembly line. The pump controller is snapped into place then fastened with bolts.

Just for fun, I wanted to see if I could make a mount that also allowed me to snap the housing into place then bolt it. I printed the part on the left.



Thanks to 3d printing I can make a mount that snaps to the Ford part with a satisfying click.



And here it is installed. That was only a few hours work to save a few seconds haha .



While I was at it, i made some parts to keep the stainless steel brake lines looking neat.



These work much better than the zip ties I was using.

[kabacj]

Now that the truck is in great shape from construction perspective with everything tidy like Ford intended, its time to add some accessories.

Our family are big skiers/snowboarders so we make many trips to northern Vermont every winter. I like using the ski carrier on the truck because it allows me to organize our gear and the pod is also waterproof. Plenty of trips start in the rain here at home and transition to snow up north.

Here is the setup on the F350.


I purchased some T track rails from Yakima to mount on the XTF fenders.

Installation was easy.

First remove the fenders. I filled in the holes I was previously using to mount the fenders with some body filler.

i marked all the holes using the T track rail as a guide. I put a fastener in all of the holes.



Drilled and tapped all the holes for 1/4 20 button head faseners.






T tracks installed and the racks slide right in.



And we are done. The XTF with a Yakima GrandTour cargo box. Ready for some snow.

[Kempo]

Hi John,

Started reading on this thread last night, amazing work as usual. Will keep on reading on it and getting your insights on different aspects of the build. Just put a deposit on a kit this week. Will be building it with my son soon. Keep up the good work and info coming.

[kabacj]

Hi John,

Started reading on this thread last night, amazing work as usual. Will keep on reading on it and getting your insights on different aspects of the build. Just put a deposit on a kit this week. Will be building it with my son soon. Keep up the good work and info coming.

HEY HUGO!! Great to hear from you.

Yes you are going to love it. It’s such a special truck. I need to catch the thread up on my upgrades. Thanks for the reminder

[kabacj]

After showing truck at SEMA then taking it out in the desert for a test run and some pics. I needed to rebuild a few things that I did quickly so I could get the truck rolling and get it to the show.

Now thats all done , so it was time to take the truck out and see what it can do.

I took it out to Rausch Creek off road park. As usual always a learning experience.



On the good side I could really go as fast as I dared on the rutted out trails. The truck was not limiting me, just my inclination to stay out of the trees going that fast.

Of course there was a jump and I needed to see how the XTF jumps.

Well for some reason I figured you just jump and it works. Of course thats not how it is. I should have known better as an avid snowboarder and mountain biker and motocross rider im very comfortable in the air. There is a VERY big difference in a truck. Body position does nothing to alter your trajectory. It’s only throttle and maybe a tap of the brakes.

But anyway jump number 1.


Ok that was nothing. Time to send it ha ha !




Oof! That was a bit hard on the front, but alls well. Let’s try a bit more gas on the launch






Ok getting better, but clearly there is some driver skill to this jumping stuff.

The other thing you will notice on every production truck jump promo add. They take off on a nice incline and land on a nice decline. That does wonders for a soft landing. We were just jumping all wheels in the air on to flat ground. Much more challenging for the suspension but very fun.

[kabacj]

With some experience off road we learned a few things.

Mud... turns out competition off road people cover their truck in wax or silicone to help shed the mud that sticks to everything... who knew. Ill do that next time.




Its time for some upgrades.

First thing is the stock steering knuckle.

Two reasons. First the stock F150 lariat knuckle is cast aluminum. Very light weight, but it will crack instead of bend when pushed too far. I am pretty sure that its impossible to overload the stock steering knuckle on the street, unless you crash into something.

Doing dumb things off road... maybe it needs to be stronger.

Second, Ford changed the geometry of the steering knuckle on both the raptor and tremor. When IKON made their steering knuckle they copied the geometry of the tremor part. Clearly there is a market for this upgrade as IKON created a product so I purchased their solution.


you can see the changes in this pic. Very subtle geometry changes but significant casting changes as well as a more ductile (but also physically heavier) material.




the stock steering knuckle easily comes off





the new steering kunckle back on.



a few benefits from the upgrade.

Stronger parts.
less severe angles on the suspension that actually allow for more travel before the ball joints bind.
increase in static ride height with less severe suspension angles.

here you can see the ride height before and after the upgrade.

Before


and after


note that normally I have the front ride height set at 11.5 inches under the lowest part of the frame. For the steering knuckle swap I had the front springs fully backed off with zero preload.

[kabacj]

After running around in the dirt for hours obviously the truck is subject to lots of vibration. It was a reasonable thing to check the tightness of all of the fasteners.

Everything was fine but I did find this part of the front shock that looked suspect.



I was really worried that I did some damage to the fox shocks. After some research I found out that the shocks are fully rebuildable and tunable so I just needed to figure out what the problem was.

First I 3d printed a shock holder out of TPU ( a hard rubber like plastic ) so I could hold the shock in the vice



The shocks are pressurized with nitrogen. Usually about 200 lbs. The next thing I did was to check the pressure to see if any leaked out



Well I does not seem like much nitrogen leaked out, but just in case I let all the pressure out of the shock.

With the pressure out of the shock body it was very easy to screw the end cap back down and re tighten the set screw. Whew thats a relief. The set screw was loose so that’s why the cap started to come out of the shock body.




Put 200lbs of nitrogen back into the shock and we are good to go.

[kabacj]

Although no other XTF builder that I know of has had issues with a loose set screw and the end cap backing out of their Fox shock, its probably a good idea to check that all the set screws are tight before installing the shocks .

Now that the shocks are sorted I figured it would be reasonable to set the corner weights. My problem is how heavy the truck is. My longacre scales have only been used to setup lightweight race cars , never a full size truck.

Longacre make a good product so in spite of the lack of any documentation on the rating of the scales or what would happen if I overloaded them, I decided to give it a try. At least the internet didn’t have anything about how some guy broke his scales putting a pre runner on them.

To limit the weight on the scales I jacked up both ends of the truck before lowering it on the scales.



Well seems like that worked. No errors or weird numbers. Looks like I have the front right and rear left stiff. Because I wanted to increase preload rather than decrease it, I added a few turns of preload in the drivers front and passenger rear.



WOW! That was easy! Just about as close as I am going to get it in one try!

I cant do much better than that with the cross balance. I didn’t bother putting myself in the truck to set the weights. I plan to go to the next level on the suspension too so this is just an intermediate step.

55.7% front to 44.3% rear bias is pretty good in a pickup truck. I had the truck loaded with two spare tires, no jack and about half a tank of gas. The numbers would be a little better with the jack mounted in the chase rack.

[kabacj]

Just like you dont need a sports car with 700 hp, the XTF does not need an upgrade of the shock package that comes on the truck from factory five.

BUT of course there are some of us that want to push performance to see what this truck can do. Thats what makes this hobby fun.

Factory five have already included the mounting points for bypass shocks which are installed along side a set of normal coil over shocks. The whole point of this upgrade is to allow for more control of each segment of the shock travel.

Bypass shocks work in a similar way as adjustable shocks we are familiar with for cars but with additional adjustment along the travel of the shock. At the same time you also keep the adjustment of the coil over. It’s a lot of control.

The first thing you need to do is package the buy pass shock so it fits in the space available on the XTF.

Fox draw the bypass shock and send over a proposal.





We used their drawing and created a model.




When virtually installed we saw the bypass had interference issues in the areas indicated below. Both the bypass circuits and the piggy back reservior could not be in the red area and the piggy back reservoir could not be in the blue area.




Luckily the bypass tube configuration is very flexible and we settled on the proposal below.

[kabacj]

With the rear bypass setup done, I needed to figure out how to fit a bypass shock in the front next to the standard spring and shock that come with the kit.

First we modeled the configuration FOX proposed.



The tricky part in the front is establishing clearance around the steering rack and tie rods. The tie rod ends swing up and down as the suspension moves through its travel. The tie rod ends also move forward and back as the front wheels travel from lock to lock.

Sure we could model all of the motions, but that would take a while and be error prone. It was easier taking a slice of the profile of the bypass shock and checking clearance on the truck directly.

A trip to the woodworking scrap box and I had a nice piece of red oak and some 3d printing I had upper and lower mounts that rotate like the upper and lower eye of the bypass shock as well as the profile of the bypass shock. Note we are using a remote reservoir in the front to keep the bypass body as small as possible.




I measured the length of the bypass shock body and moved the profile to that position then cycled the suspension and the steering lock to lock.



You can see from this view that the tie rods overlap the body of the bypass shock, but they never get close to the bypass body as the steering and suspension cycle through their motions.