F-350 Hi-Lift build tips thread.
 

Since this is a tech thread, please keep this thread for build tips and questions only. There is already a F-350 discussion in Chit-Chat.


When you build this truck, don't get in a rush. Each step in the manual is fairly "busy". Pay attention, take your time, and have fun building this one. ;-)


Here's a few little things I did along the way while building my Hi-Lift:

• My input shaft to the transmission (BA29, Gear shaft A) was bent near the step on the threaded end. There's a shoulder right next to a thru hole. This point (to me) seems to be a weak point and a spot where it'd be easy to have a tweaked shaft without noticing it. I didn't notice mine was bent until the tranny was assembled and in the chassis. My indicator was the lock nut rotating all over the place.
  
  
  
  
• The kit manual says to use a 2 leaf pack for the "soft" setting. The two leaves consist of the main leaf with eyes and a 2nd leaf that extends nearly the entire length of the main leaf. I chose to use the shortest add-a-leaf in the bag as my 2nd.
  
  http://www.projecttwin.com/files/350leaf.jpg
  
  
• One way to prevent axle wrap while running a soft leaf spring pack is to take one of the 4-link mounts (L1, L10) and attach it vertically to the rear axle next to the diff housing. I used two of the included 30mm or so screws to pass through part L1 as well as the axle housing. Since the tabs on the four link mount (L1) are a bit wider than the axle is deep, I used a couple of 3mm nuts (small black nuts from the kit) to fill the gap. Just slide the nut between L1 and the axle housing and tighten the screw. Use a 3mm locknut and a washer on the remaining bit of the screw to lock L1 in place. Another 3mm screw from the kit was used to mount the traction bar and a short length of 3/16" brake tubing acts as a bushing for the traction bar and is held in place by a 3mm nylock
  
  http://www.projecttwin.com/files/350/tractionbar/1.jpg
  
  Then make a small link that spans the distance between the 4-link mount and the screw for the leaf front hanger for the left rear leaf. To make this I used two spare ball ends from the kit (L9) some threaded rod (4-40 I think) and some 3/16" brake tubing as a sleeve. Sorry, no pics of the assembled traction bar, but you get the idea. Slide one end of the traction bar over the short 3/16" brake tubing bushing and tighten the Nylock.
  
  At the frame end of the traction bar I removed the rear screw for the leaf spring hanger. I used a longer screw (30mm I think) to bolt a spare damper collar in place. The damper collar will actually rest against the lip of the frame rail, not agaist the "bed" of the rail. Install L9 to the collar using spare O-rings from the kit. Install a 3mm nylock to keep things in place.
  
  http://www.projecttwin.com/files/350/tractionbar/3.jpg
  
  
  Another view of the rear mount.
  http://www.projecttwin.com/files/350/tractionbar/2.jpg
  
  
  
  There you have it...no axle wrap and a soft suspension. ;)
  
  
• For you brushless nuts, a Holmes Hobbies Revolver will fit just fine, but you'll need to flip the pinion gear on the motor shaft. The shank of the pinion will interfere with the cover for the input gears. I reamed a hole in the cover to make room for the shank of the pinion.
  
  http://www.projecttwin.com/files/350tranny.jpg
  
  
• The kit comes with parts (L4 and L5) to change the caster angle on the front axle. Although these are intended to be used on the front I decided to use them on the rear to rotate the pinion up a hair. Doing this will cause the tie rod on the rear to make contact with the rear leaf springs when the rear suspension compresses. The easy fix is to build two short steering lockouts and eliminate the tie rod completely. The instructions say to build one at the bottom of step 31 in manual, but parts are included to build two of these lockouts.
  
  
• When you build the axles install a Traxxas teflon shim (TRA1985) behind the pinion gear so it meshes a little deeper with the ring gear.
  
  
• Remove the tab on the pinion/spur cover that the shift rod passes through. With this tab in place you have to remove all the shift hardware from the rod to change motors or inspect mesh at the pinion/spur.
  
  http://www.projecttwin.com/files/350/tab.jpg
  

Feel free to add tips/tricks you guys find as you go along.

You will need to update us with what ESC and battery you are running when you get to that point JIA. I will be interested to see how much strain 3rd gear will put on the motor and ESC.

Got your diffs open?

Have a look at the leftover parts. They give you 4-link mounts ;-)

I believe the leaf that is placed above the main leaf is necessary to control axle wrap. I used mine, and also the short leaf underneath the main leaf. The "Normal" Tamiya set up. However, I left the coil spring out of the shock. The rebound dampening with it in place is pathetic, and practically non extistent. Ready to run the truck has a small amount of sag.

That's what I did, too. The anti-wrap leaf, and used the shortest extra leaf as the stiffener. No coils, and it's surprising how much that softens the suspension. I got almost 3/4 inch of extra flex just from that.

You can use a half leaf that runs from the shackles to the front attachment point to lessen axle rap. And that would not add spring rate

Cool info. I'm defentally gonna buy one. You forgot the tip to take off of work, it helps with having the whole day to play with it and get paid for it

EDIT Forgot my question. Will the springs with only the main spring become warped? I read somewhere that someone was haaving a probem wth this on a different rig. Also, is there enough room to use an aftermarket shock like an integy or somthing? I already have a few around and would like to use them.

The kit is a blast to build, Just Finished mine a few hours ago. It is a little stff so I plan to remove the shock spring thanx for the tip.

P.S. Did you guyz use bearings?

Yeah thanks for the tips JIA made my build go alot faster since you found all the small modifications and setups to be made.

I wasn't going to use bearings but at the last second before building I decided I didn't want to build it again later just to put bearings in. Thankfully I live in LA and was able to find a shop with the right quanities/sizes needed.

I bought twenty bearings, and that isn't even half of the total of 42 pieces.

I used a big-rig bearing set from Hong Kong, and some 5x11's from my stash. There are bearing kits available already.

I added another tip and merged all the tips I'd posted into the first post.

JIA, do you have a pic of the ladder bar setup you were talking about?

Added the traction bar images and how-to to the first post.

http://cgi.ebay.com/RK-Ball-Bearing-...QQcmdZViewItem

Here is a complete bearing kit. They get more expensive if you'd like. They only cost $19.74+$7.10 for shipping

Jason just curious what electronics you're using with the revolver?

I was going to use a Quark 33 but decided to go with the stock motor and Super Rooster for now.

Yeah I forgot to pick up a UBEC and the Mamba definitely can't handle powering both servos. The bit I drove the truck with the Revolver I'm pretty happy with it and it didn't operate any hotter than the TLT in 1st and 2nd. (I didn't run it much in 3rd)

I'm gonna one-up your gear-cover mod, JIA :mrgreen: I don't even have to take the servo out to access the motor 8)

Wierd, my mamba works fine w/2 servos. Albeit, a JR 290 & Z590. Don't need much for the shifting.