My reply from Gary Kyes from Losi

[alien13]

I was the project manager for the Speed-NT and was a bit shocked to hear of your problems. We are definitely interested in how/why you have had these problems when thousands of other customers have not. Please advise what you were doing when the metal shaft broke. We did repeated drop tests revving up the engine to top speed and then dropping it on the ground to test the gears. We made several changes to both the material and the tooth profile to get these where they wouldn’t fail after 50+ such successive drops (which should never happen in actual use). What tires where you using? Where you running on dirt or asphalt? What other damage did you find in addition to the broken shaft when this happened. Same for the gears. Did you make any modifications to the model? We are always looking for ways to improve our products but if we can not re-create the problem it is hard if not impossible to see what needs to be done.
I have never heard of a rod breaking in the 3.4 engine during normal use. Did you send the broken engine to Horizon for replacement? We tested these engines with 40% nitro both on the dyno and in the truck at over 38,000 rpm without failure. If there is a material problem we would definitely like to advise the supplier as we spec out 7075 T6 aluminum and are given certs that this is what was delivered. This is far superior to any other small block RTR engine and is what is used in our racing engines. Again if we know more about what the conditions of failure was we can try to re-create them. I assume you did not let the engine free rev without load on it?
You sound like an experienced RC car guy so I assume you have nitro engine experience and any insight you can supply would be most appreciated.
Thanks for bringing this to our attention and your help to figure out why you are having problems.
Best Wishes,
Gary Kyes
Losi


I replied to him telling him pretty much the whole story from when I get the new engine and on. Hopefully, something good will come of this.

 

[alien13]

My response to him:
I did contact Horizon about the engine, sent it in an received a new replacement. I am very thankful to Losi/Horizon Hobbies for that. I had tuned it. Here's the scenario since that point. After tuning it, running at about 200F, I did a few speed runs up and down the neighboring street to show it off to some people across the street. It ran like a champ. No issues at all, I thought I had something great. I took a break for about an hour, then went back out, warmed it up, made about three more passes when the 2nd gear stripped flat. I pulled that and replaced it, also replacing the idler since they both come in the same package.

After re-assembling the gearbox, I took it out again, only to discover that the great tune I had was gone. The 200F temps I got before, were also gone. I was lucky to hit 140F steady. So I figured air leak. Upon removing the backplate, I discovered that a screw was loose. This was the first time I had pulled it apart, since receiving it from Horizon. I sealed the backplate and carb, put it back in, and proceeded to tune it again. Was finally getting a good tune, still never hitting WOT on asphalt in front of my house, and drove it back to myself, to do a quick needle adjustment. When I went to take off, nothing happened. I pushed it forward a couple of inches, hit the throttle, it started to go, but I could hear the crunch of the gears, so I pulled it apart to find one tooth missing, and the tops of the rest of the teeth sheared. At that point, I put it down, and didn't want to see it again.

After cooling off for about an hour, I went back out, looked to see what the issue was, and what the repair cost would be. I pulled the diff apart, everything looked fine, with the exception of the outdrives, which in my personal opinion are too loose with rubber o-rings, I think they should have bearings instead. I could wobble the outdrives, and I think that the whole diff shifted under load, shearing the teeth.

About a week later, I looked a little further into the gearbox, because I was curious if the bearings in the gearbox would be a close enough match to the o-rings, or at least get an idea what size I could use instead. To do so, I pulled the center shaft assembly to look at the bearings. That is when I first noticed that it was broken. It broke right at the weakest point, the pin hole for the idler gear. Looking at the idler gear, I noticed that the teeth were worn down some, but not as bad as the diff. Knowing I had a spare, I tossed it.

At this point, the Speed-NT is merely a wall decoration. I like it, and when it works properly, I love it. Unfortunately for me, the only place I have to run it would be on the street in front of my house. I rarely have the time to leave, as I am usually quite busy, and this was something I was hoping to have some fun with, in between getting home from work, and taking care of my kids.

It actually took about two weeks before I emailed Horizon about this. I was annoyed about it, and just didn't know what to do until somebody told me to at least send my story and pics to product support. While you tell me that you haven't heard of these problems, I read about them on the net. I am not the only person who has suffered this fate. I understand that you put alot of research into this truck, but in the end, not every part is of the exact same quality. I wish I was the only person that had this issue, then I would still have more faith in Losi products.

When I have some additional funds, I'm sure I'll get the parts to put it back together, but I would like to see an all metal gear set for this. Until then, I just purchased a Losi 454 for an 1/8th scale truggy I have, I do hope that it restores my faith in Losi products.

Thank you for your concern,
Bill

PS, I haven't a clue what the con-rod snapped in the first engine, it was tuned great, and ran like a pro. I even took it to a local track and it was great.

And in turn, he responded again:

I am aware of some gear breakage but our investigation found that a lot of this was done in an abusive nature – one fellow was repeatedly doing back flips off of an skateboard jump! He even sent video! I checked with our customer service department and they have only one call concerning a broken shaft. Unfortunately the web/forums can be somewhat less that honest. Was the two – speed shifting at peak power or before? I will revisit the fit of the outdrives as I have a cut-away gear box used to check gear engagement. Our drop testing was pretty hard on these pieces.
I would like to send you new parts and if possible get the broken parts back so we can do an analysis to confirm materials and heat treat. Please send me a list of all the parts you would like to have (not just what is broken) to rebuild to “like new condition” and I will see to it. I will also need your shipping address. I wish we hadn’t used the test truck for another project as you would be amazed at how beat it was from all the testing (the bottom of the chassis was worn through at both the front and back from big air landings) we did. We had over 22 hours of documented testing on it with the same engine.
Thanks again for taking the time to help us. I can’t blame you for not believing it but yours is quite the opposite of what most dealers and customers experience…. Or at least that’s what they tell us.
Thanks again,
Gary


In turn, I told him what parts I had left, and what I would be willing to send. (Pretty much the whole gearbox, minus the 2nd and idler gears that were tossed) Then I told him that all I need is the diff, center shaft and 2nd/idler gear set, but because I don't know what the problem was that started all this, I would like a new trans. I left that decision up to him.

 

[olds97_lss]

Well, at least you were thorough in your explanation and didn't let your anger/frustration drive your emails.

I'm going to go download the manual to see what o-rings your talking about... I don't have the truck, but now I'm curious.

Not to bash losi, but I have a jato. I bought it used (as I do most of my vehicles anymore) and it's been a great little truck. My only long standing issue is busting crank cases and crappy tune of the TRX engines. I think I have the crank case issue sorted, but the tune I'm afraid is a lost cause. May actually look into getting that Dynamite traxxas drop in engine.

I really hope all your problems are due to a bad mold job on the case or something. Like you, I have minimal spare time to run my rigs and most of which is done alone at a skate park early in the morning before kids show up. I know what it feels like to have constant issues that eat up all your running time. It sucks!

 

[alien13]

Update: Wednesday I emailed Gary asking what was up since I hadn't heard from him in a week. He replied stating that some of the parts he wanted to send me were out of stock, and that he would keep in touch.

Today I received an email from him stating that there is a box coming my way, and he asked if I could send the broken shaft, and the broken con-rod. I told him Horizon kept the old motor, and gave him the work order number so he could attempt to track it down.

**FINGERS CROSSED** Hopefully the "box" he is sending my way contains either a complete Speed-NT trans, or all the parts to build one. And since he's only asking that I send the center-shaft, I get to keep the old trans for parts!

 

[smkynutz]

So what happened? Did losi make it right? I have 3 Traxxas nitros now and have been thinking about a losi. Gary seems to make it sound ok in the email, but I need to know how it was resolved.

 

[alien13]

There's a thread somewhere around here with the results, but he ended up sending me about $150 in parts, including enough to rebuild the tranny.