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How-To: LST Performance Upgrade Kit

4/18/2006 by

Copyright:© 2006 Horizon Hobby, Inc.

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Whether you love tearing up your back yard, the nearest park, or the local race track, enthusiasts all over the country have spent countless hours behind the wheel of Team Losi’s 2005 RC Car Action Truck of the Year, the LST. Recently, Team Losi unveiled its follow-up to the LST, the LST2, which features several revisions and upgrades. To allow access to the improved features of the LST2, Team Losi engineers have put together the LST Performance Upgrade Kit for owners of the original LST. We took a standard LST and installed the Performance Upgrade Kit and learned several interesting things along the way. Read on and we’ll walk you through the miscellaneous steps and give you a few tips and pointers as we go along.

Before the Big Plunge

Before you dive in and start ripping things apart, we’d like to offer some advice. Performing this upgrade does require a fair amount of mechanical ability. If you’ve performed basic maintenance on your truck before, you should be able to install the Performance Upgrade Kit without many surprises. Of course, this is also a good time to do a thorough service of your LST if you have not previously. If you have a hard time telling an Allen wrench from Alan Alda, you may want to consider simply purchasing an LST2. Additionally, while the Performance Upgrade Kit will improve the handling and durability of your truck, there are still several benefits and features that an LST2 will have that the LST will not, and therefore, you may simply be better off with an LST2. Judge your ability and intensions properly before you start so you make the decision that is right FOR YOU.

Tools Required:

  • 1/16", 5/64", 3/32", and 2mm Allen wrenches
  • ¼” nut driver
  • Pliers
  • Parts tray

Removing the Front and Rear Ends

The LST utilizes a modular design, which allows you to work on one portion of the vehicle separate from the rest of the chassis. This modular design also makes this conversion easier, as you can work on one section of the truck at a time without disturbing the rest of the chassis. I began my work on the rear of the truck and worked my way forward. Disassembly started by removing the fuel tank, rear shock tower, and the shocks. From there, removal of the rear end is as simple as removing the four screws from the underside of the chassis and sliding the rear end away from the chassis. All in all, it should take you less than ten minutes to remove the rear end from the truck.

Removing the front end from your truck is nearly as easy, , although you won’t need to deal with the fuel tank issue. To remove the front end, you’ll need to remove the front steering links in addition to removing the four screws that thread into the underside of the bulkhead along with the four that pass through the shock tower. Beyond this, disassembly is identical to the rear of the truck. 

Time to Get to Work

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The LST Performance Upgrade Kit features the same beefy suspension components found on the LST2. The Kit includes the same upgraded front and rear hub carriers and larger diameter bearings.

Once you have the rear of the truck free from the chassis, you can really roll your sleeves up and get to work. You will re-use the inboard suspension pins, but don’t be so quick as to just install them and go. Once they’re free of the A-arms, inspect the pins to verify that they are straight and have not become bent in a crash. If they have been bent, simply replace them with a fresh set (LOSB4101) and you’ll be in great shape. Or you may wish to consider installing titanium-nitride pins (LOSB4102) at this time. While you are removing the old suspension components, you can also remove the rear toe-in adjuster; this part is not necessary with the new suspension package.

I began my re-assembly at the hub carriers and worked my way inward from there. The new rear hub carriers are much beefier, redesigned and reinforced to provide even greater durability in the event of a hard crash. New outboard hinge pins are included with the Update Kit, but you’ll need to recycle your old E-clips. Before you mount the hub carriers to the A-arms, make sure you install the bearings and driveshafts. You’d be able to install the bearings and axles later, but doing this before you mount the hub carriers is much easier.

Inside the Diffs

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The LST2 incorporates a number of upgrades in key areas. Thicker steering knuckles, larger diameter axles and driveshafts, and wheel hexes all come in the Performance Upgrade Kit. The new parts are shown on top, with the originals on the bottom.

Once you have the new A-arms, driveshafts, and hub carriers installed, you can turn your attention toward the differential cases. The gorgeous blue aluminum diff cases that come as standard equipment on the LST2 are also included in the Performance Upgrade Kit. Three screws keep the diff cases closed and sealed, but you should be aware that new diff case screws are included with the upgrade kit. Be very careful not to use the 4-40 screws; they are too big and could potentially break off in the screw hole. If the screw doesn’t simply slide through the top diff case, it’s not the right screw. The correct screw is a 2.5mm screw, not a 4-40 and it will drop right through the top case before it threads into the lower case. Just to be on the safe side, test the fit before you install the cases in your truck.

While you have your diffs open, it’s the perfect opportunity to perform some basic maintenance on them. The gears in the LST come packed with thick grease right from the factory. If you’ve run your LST quite a bit, be it on the race track or tearing up your back yard, changing out the grease may not be a bad idea. Dynamite Nitro Force (DYN5505) really cuts through old differential grease like a hot knife through butter. As you are cleaning your diff gears, inspect them for broken teeth or excessive wear and tear. When refilling the diff cases, you can use a variety of different greases (available in the automotive department of most stores) as well as liquid silicone fluids to alter the diff action. I recently spoke with Team Losi’s Adam “The” Drake about the setup he uses on his personal race-prepped LST and LST2. Adam recommends using 10,000wt diff oil in both diffs, which is available from a number of different manufacturers such as Sportwerks (SWK2908) and OFNA (OFN10235).

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Stronger blue aluminum differential cases replace their molded counterparts.

You may notice the gear mesh between the ring and pinion gears is a little tighter with the aluminum cases in comparison to the original molded parts. If necessary, the fix for this is easy; relocate the shim on the outdrive bearing from behind the gear (which moves the ring gear closer to the pinion gear) to the other side of the diff (which moves the ring gear away from the pinion gear). It only takes a few seconds to try the shim on both sides to get the tightest mesh with the least amount of backlash or binding. This slight modification will give you a little more backlash between the gears, allowing them to rotate more freely. Before sealing the diff cases back up, you would be well served to coat the ring and pinion gears with a generous coating of grease as well.

Transmission Updates

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There are a number of upgrades to the transmission thanks to the Performance Upgrade Kit. They include new transmission cases, a new Hi/Lo get selector, and a new secondary gear cover.

Some of the updates in the Performance Upgrade Kit are more subtle than others. The Upgrade Kit includes a new transmission case and Hi/Lo selector knob. Designed to function smoother, the new Hi/Lo selector gives you a better feeling for when you really are in one gear versus another. Making the transition from one gear casing to the other can be a rather messy job, especially if you grab the grease-smeared gears. I simply held the gear case brake-side down, and removed the other half of the case. With the gear case open, I placed the new opposite half against the old casing I was still holding, that had all the gears in it, and flipped the gear case over. This forced the gears and shift forks to drop right into place in the new half case and made it easier to remove the Hi/Lo shift mechanism. Take your time during this assembly step; if the shift forks aren’t properly lined up, you will find yourself stuck in one gear or stuck in reverse. A few extra seconds of attention here can save you hours of aggravation down the road. Once I transferred that to the new case, I liberally greased all the gears and bolted both new cases together and installed the new gear selector. Again, pay particular attention to what may otherwise seem like a basic swap. The Update Kit includes a shorter aluminum standoff for use in the shifter mechanism. If you try to use the old standoff in the new shift knob, you will run into troubles.

In addition to the new case and selector, the Performance Upgrade Kit also includes a new internal gear cover to further prevent dirt, rocks, or small pebbles from getting into the clutch bell or spur gears. To accommodate the new spur gear cover, new ladder bars are also provided that feature two new screw holes in them for mounting the internal gear cover.

420-Size Wheels

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The Performance Upgrade kit includes a set of 420-size wheels. The tire choice is completely up to you, but there is a wide variety of treads and compounds to choose from.

The LST2 comes with an all-new 427 engine that delivers a ton of torque. While there aren’t any engine updates for the original LST engine in the Performance Upgrade Kit, the original .26 engine that the LST comes equipped with is still a stump-puller. This torque can place undue stress on the wheel hexes of the original wheels, potentially rounding them off or rounding off the wheel hexes themselves. New 20mm wheel hexes are provided with the Performance Upgrade Kit along with new 420-size wheels. Your choice of tires is up to you though, as none are included in the Performance Upgrade Kit. Team Losi’s own ATX Tires (LOSB7202) hook up rather well on a variety of different surfaces. Additionally, any “40-size” tire will be compatible with the provided rims.

Don’t fret if you have a box of tires on 14mm rims. If this is the case, Team Losi has you covered there too. While not included in the kit, there are 14mm drive hexes (LOSB3514) that work with the new axles and the original LST rims.

Key Differences Between an LST with Performance Upgrade Kit and the LST2

While the Performance Upgrade Kit will improve the performance and durability of an LST, there are still other benefits to the LST2 that are not included in the Performance Upgrade Kit. Weigh the options before deciding to install the Upgrade Kit or purchase an LST2.

LST 2 versus the LST with Performance Upgrade Kit

Some of you may be reading this and wondering what the benefit would be of running an LST2 versus an original LST with the Performance Upgrade Kit. While the kit will upgrade your truck with the same LST2 suspension, diff cases, side rails, and more, there are several features that will only be found on the LST2. The LST2 features the same basic shocks as the original LST, but the LST2 comes with threaded body shocks. The threaded bodies make changing your ride height and pre-load an absolute snap. Also, the Performance Upgrade Kit does not include any upgrades for the Mach .26 engine, clutch, or clutch bell. The LST2, however, does feature the new 427 engine, one-piece clutch bell, and new aluminum clutch shoes. The LST2 includes the same 420 wheels, but they also come wrapped with ATX tires front and rear. The Performance Upgrade Kit includes these same wheels, but you’ll need to pick up a set of tires too. And finally, with the LST2, you don’t need to pick up a wrench to get the truck up and running since all the hard work is done for you. The choice of whether to go with an LST2 or to update your current LST is completely up to you.


Feature
LST

LST With Performance Upgrade Kit

LST2
JR XS3
x
x
x
Losi Spin Start System
x
x
x
Oversized Shocks
x
x
x
17mm Wheel Hex
x
 
 
Adjustable Rear Toe-In Links
x
 
 
Oversized Ball Bearings
 
x
x
Revised Suspension Arms
 
x
x
20mm Wheel Hex
 
x
x
Revised Hi/Lo Shifter
 
x
x
Aluminum Diff Cases
 
x
x
Secondary Gear Cover
 
x
x
Updated Drive Shafts
 
x
x
NiMH Reciever Pack
 
 
x
Aluminum Clutch Shoes
 
 
x
One-Piece Cluch Bell
 
 
x
Threaded Shock Bodies
 
 
x
Mach 427 Engine
 
 
x

Adam Drake’s Race Setup

  • 30wt oil front and rear
  • black springs front and rear
  • 10000 diff oil front and rear
  • thin sway bars front and rear

The rest of the adjustment (shock locations, ect.) are the stock locations.

The LST is a terrific truck; being awarded the 2005 RC Car Action Truck of the Year is proof of that. The LST Performance Upgrade Kit is an excellent and relatively inexpensive way to improve its performance and durability without having to purchase a whole new truck. While there are features on the LST2 that you will not have, even with the upgrade kit, there is still significant improvement in the handling and durability of your LST. Sounds to me like it is the perfect time to roll up your sleeves, grab your tools, and start wrenching.