What to do before driving a used Monster Truck?

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MotoGod

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OK so here's the scoop. I picked up a used Warhead that looks pretty decent. I got it fired up, everything works great so far. My problem? The previous owner is either a moron, or just never used Loctite on ANYTHING on this truck.

So I drove it twice, and both times I have had a bolt loosen and cause failure. First one was a spur gear bolt. It backed out and hit the clutch bell and of course killed all forward motion. I made sure I checked ALL the spur gears bolts and tightened them all down. Only the one that backed out needed it.

So I ran the truck again this morning. I made it @ 5 laps around the yard just bashing around and getting the hang of things when the truck started to slow down like ti dropped an anchor. I brought it back over to me and when I slowed down it stalled. Upon further inspection, all 6 bolts from the spur gear were now MISSING and the metal spur gear was ground down a fair amount (no more blue anodized finish left) and the clutch bell had some damage as well.

So now I'm thinking I really can't trust most of the assembly done on this truck prior to what I have done. So my real question is what do you guys do when you buy used vehicles? What kind of prep work needs to go into them to ensure they stay running and moving beyond the obvious put gas in it and charge the batteries. Also what kinds of spare parts are typical with most RC vehicles that will help in the event of a failure?

Brand new guy here, and when I was racing motocross....we would tear down new "used" bikes to ensure everything was greased and not destroyed before even throwing a leg over it. A bit more of a safety issue with an MX bike, but I'd like to be able to run this thing for more than 5 minutes without some needed part popping off.

So what kinds of things should I inspect on this truck before I get it back out and run it next time? No shops near me stock parts, so I don't want to be down 4 days for every 5 min I run it ;-)

One final question as well. After I saw the problem, I obviously didn't drive the truck anymore, but the motor almost sounded like it was boiling fuel (kinda sounded like a radiator dumping excess pressure) when I got it back on my truck tailgate. I know it has some increased load from the spur gear and the clutch bell rubbing together, but is that a normal sound from these little Nitro motors after being run? I wasn't going nuts, but I made a few passes in the front yard wide open for 100yds or so each right before it quit.
 

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As you just discovered you need to Loc-Tite any metal to metal hardware.

As for the "boiling" it sounds like the tune is too lean. If you spit on the head and it sizzles right away it is way too lean. Get a temp gauge asap!
 

Racer 1966

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Like you said about your bikes, I check out most evrerything on a used truck. I happen to be doing that to my Warhead now. It is supposed to have only break in plus 2-3 tanks on it. I took the clutch bell off tonight to find a broken spring. I'll be making a post in my thread in the Members Projects forum soon.
Some of it may be that these trucks are problematic units, there has to be a reason for them to not be popular and be discontinued. They are built really similar to a Savage so I am going to see if some parts can be interchanged or slightly modded to work.

The boiling may be as you thought, from the engine working extra hard due to the interference form the lost screws. Do you have a temp gun? Handy for tuning, get one if you don't already have one. There's one in the fs forum for $12.
 

MotoGod

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No temp gun as of yet. Trying to kind of "limp" into this hobby at the moment so my pregnant wife doesn't rip my manhood off. lol So I guess a temp gun will have to make it's way into my toolbox next. lol I ordered some new parts...so as soon as they get here I'll just tear apart this truck and loctite everything under the sun. Seems like my best course of action at this point.

I appreciate the input ;-)
 

syphon68

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I bought a revo used last summer and visually went thru it to make sure things were in shape but kept having stuff come apart. I ended up disassembling the whole thing and upgrading anything broken or worn. I haven't had any problems since except for crazy driving related issues:hehe:
 

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No temp gun as of yet. Trying to kind of "limp" into this hobby at the moment so my pregnant wife doesn't rip my manhood off. lol So I guess a temp gun will have to make it's way into my toolbox next. lol I ordered some new parts...so as soon as they get here I'll just tear apart this truck and loctite everything under the sun. Seems like my best course of action at this point.

I appreciate the input ;-)

I saw a cheapy one at autozone yesterday, $20. Even if it's not 100% accurate, it's better than nothing. You can test it on boiling water to see if it's off or not, 100 °C or 212 °F is what water boils at.

Anyway, any time I get a used rig, I take it completely apart (including transmissions/diffs) if for nothing else but to inspect wear and look for worn parts that can end your day. When putting it back together, I usually clean every part and inspect for cracks, stress marks and I use locktite as I would normally do. Metal to metal, locktight. My autozone carries the gel and liquid.

I've found that locktite stick works better than the liquid stuff. Locktite gel is better yet. Just seems to hold better, but not permanent so you can still take it apart.
 

MotoGod

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So it looks like the spur gear bolts flying off caused more damage than I originally thought. Just my luck!

1. Spur Gear got ground down, it's metal so I may be able to re-use it.
2. Clutch Bell = toast
3. Transmission Cover = Toast
4. Spur bolts are gone
5. 2 motor mounts are gone
6. 3 skid plate screws are gone
7. A few e-clips are gonezo

Nothing too too serious, but I do have a question about the transmissions in these things. It has a rubber plug up top which appears to be an oil fill point. What kind of oil runs in these trannies, and how much of it? I need to find a new tranny cover and I think if they carry oil I may have found the source of my "boiling" noise. Fluid was kind of all over the place as I was tearing down the truck today. I thought it was Nitro at first, but was WAY too slippery for fuel. Then I found the hole in the case behind the spur.

So my truck is now effectively "in a box" lol. I took EVERYTHING off this darn thing and I'm probably going to paint a few pieces and replace a bunch more before I put her back together. Fun Fun Fun! I should have just bought a kit.....it's pretty much what I have now anyway. haha
 
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Racer 1966

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The rubber plug is an access hole for adjusting the shift point, do not put any fluids in it.
 

MotoGod

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Interesting.....Maybe it was Nitro all over the place then. Hmmm... Oh and the more I took off the harder this sucker appears to be. Things are screwed to other things in a strange way, but once you get used to it, it doesn't appear to be too too bad. Kind of strange that it has no real "frame" Everything is screwed into the aluminum sides and a few things screw into the skid plates.
 

MotoGod

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I was planning to take some during re-assembly actually. All in all it only took me maybe 2 hours to tear this thing down to a pile of nuts and bolts. The only things I left in tact were the front and rear suspension systems. Doesn't look like I'll need to Loc-Tite anything there since it's all plastic, but I'll dig deeper when my parts get here. I had to place yet another order with Tower yesterday for the other broken pieces. hehe
 

MotoGod

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That's how I'm looking at it really. I mean I have already spent 10X more time working on it than I have driving it. lol Two 5 min stints and @ 4 hours with tools in my hands. This thing is VERY simple though. I'm glad I raced motocross to be honest. Ripping an MX bike down to the frame vs an RC car....RC car is a joke! I just had to write down which servo went to which channel. If I lose that paper I'm screwed though....
 

pitbull14218

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Ya when i bought my savage it was ok, but really dirty and looked beat. 2 rims where installed wrong where the tires were facing the wrong way, i have a feeling a young kid bought it and probly didnt break it in correctly at all. But it seems to run ok.
 

chattin

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my advice stay away from duratrax.. i have never been a fan of thier stuff..
 

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as said above best to treat anything used like a bike. obviously less of a safety issue on rig - but they can be dangerous if you have a run away! always a good idea like Olds said to do a TDI (tear down inspect) on a used rig definitely save you headaches and money in the long run
 

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