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Tamiya Hilux Suspension Rebuild

This one is for all of you Tamiya High-Lift series truck owners. Just like RC Truck Stop style, most of us don’t shelve queen our rigs. I drive mine hard and I’m not afraid to get it dirty and push my rig a little now and then. This does come at a cost with such a detailed, scale machine with so many true functional parts. So after beating the trails over the summer and trashing the sand beaches, the suspension is starting to get a little rough and sluggish. It’s time for a rebuild. Let me show you a few good ways to take care of the original scale suspension on the Tamiya Toyota High-Lift.

The scale suspension on the Hilux is awesome. During the kit building, as most of you know, you can change the strength of the leaf springs by adding and removing leafs. If you built it to manual specs, the ride is pretty rigid. However, if you remove a couple leafs you will have a much softer ride and decent axle articulation. The downside to this is that the leaf springs are taking a bit more abuse and the shocks need to be in check. I have had problems with the leaf springs, but I will get to that a little bit later. For now, lets focus on the shocks.

Once you have the shocks off, it’s time to take a look at them. As you can see, some fluid has leaked out and collected at the base of the body of the shock. You may also note some sand, and dirt.

I know any oil on any surface will attract dust and sand and dirt. There is no avoiding this. However, with proper maintenance you can reduce the wear and tear on the parts and the amount of leakage.

Disassemble the shock assembly and check the O-rings and spring. Make sure the internal spring isn’t over compressed and permanently crushed. The O-rings need to be intact and not worn out or broken. When in doubt, use new O-rings.

Just because the shocks are sealed doesn’t mean junk doesn’t make its way into the shock body. After time, the grit gets in and is scraped along the inside wall during suspension articulation. The shock shaft is steel, but the body is aluminum. Grit inside is not good and will score the interior wall and cause leakage and cause the shocks to bind up.

Carefully check the O-rings; if they are damaged, they should be replaced. You can see a small amount of shaft scoring and discoloring due to the O-rings wearing out and causing the shaft to contact the lower outside tapered end of the shock body. This will also cause binding.

See that little hole on the inside eyelet of the shock cap? I know you do, but do you know what its purpose is? It’s pretty critical for full shock operation. Because this shock isn’t the more traditional “oil-filled” type and is, instead, just a damper with internal spring, the air accumulating inside the shock body needs to breath. Remember the two O-rings on the shaft? That is going to produce a good seal and will keep the grease inside the shock.  But air transfer still needs to occur. If this hole is plugged with dirt, the dampener shock may not fully compress and may blow out the lower O-rings. Causing a “leak” Make sure this part is free and clean of debris. The hole also provides another purpose; it helps lubricate the pivot mounting ball.

That dirt inside the dampener body needs to go! I use cotton swabs doubled up and a twisting motion inside the body and pull the dirt out.

Once the parts and pieces are cleaned. It’s time for re-assembly. Using new O-rings and the proper grease, it’s time to go together. Can you use any kind of grease? No! Remember all types of rubber, like O-rings, are affected by different lubricants and oils. Using the wrong kind of lubricant can cause any O-ring to shrink or swell, and after this happens, it’s garbage. This same rule applies for fluid-filled shocks; it has to be the right kind. For example, one of my friends once used automatic transmission fluid in his shocks cause he couldn’t wait to assemble his kit. Well, within weeks the rig started to leak on his table. He tore down the shocks and found the O-rings in the shock cap had doubled in size. For this application, simple white grease is good.

With the shaft and O-rings lubricated and the spring in place, it’s almost done.

Hey, what’s this?  A zit? No, it’s extra grease. Because of the air lock seal at the bottom of the shaft I was talking about. This is normal, but be sure to wipe the excess off.

The shock mounts are an important item to check too. The O-rings on both sides of the eyelet need to be in good shape too. Again, if broken or cracked, change them. The small hole with grease coming out will help keep this pivot section lubricated and free moving.

There you have it! Your shocks are now back in business and ready to take on more trails. But, I feel like I’m forgetting something…

Don’t ignore the leaf springs. This type of suspension is a two part design and these components work together. You can’t run with just one working.

What’s the big deal with leaf springs?  For starters it’s typically either this or a linked of setup like a 4-link. Many have gone with linked suspensions, and I have such a setup on my Tamiya TLT-1. But, if you have a scale rig, leaf springs add an awesome touch of realism. What can go wrong with a leaf spring? What’s its main purpose?

Leaf springs dictate ride height, axle location and wheelbase. Overtime, the springs can sag and get over compressed.  Eventually, the spring can even break. Running on some extreme scale trails can really workout a setup like this. When looking at the leaf spring, make sure the leaf is even. One side isn’t lower than the other. Make sure the “nip” of the spring is within conformity with the others or when compared to a good leaf spring. The “nip” is the distance from the base of the spring were it mounts to the axle, to the top of the spring were the shackles and leaf mounts are. There is no spec for this, but check the build manual and see if the spring is still in visual check. My leaf springs checked out as OK, so my Hilux suspension only needed shock dampener maintenance.

Once the leaf springs and suspension are back together, the last thing you want to do is check the leaf spring shackles and mounts. The leaf, as it compresses will get longer, and the shackles will need to move freely to allow the upward axle movement.

The Tamiya High-Lift is a great kit, and like its older cousins, the Bruiser and Mountaineer, these can last a long time with proper care. Once Tamiya stops production, and we know it’s already started with most of the spare parts, keeping this scale rig in good shape with regular maintenance is key, no matter how tedious the cleaning and maintenance can be. It will help make this model last years longer.

 

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4 Comments

  1. No problem Elmira, glad to hear it. If you have any questions about the High-Lift series, or this article by all means, please ask. We at RCTRUCKSTOP.com are always trying to be informative, and helpful anyway we can.
    Happy Holidays!

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