themountain
I joined the Band!
Excellent job with what you have done until now! I was on the brink to get one but was cautious because its a rc4wd �� ...so far I was probably ok not to get one. I wait if I can pick it up used some day.
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Fallen's RC4WD Miller Motorsports #4421
- Thread starter Fallen
- Start date
The new (old) steering servo is in and works fine. I stole the old servo from my Bronco and bought a new one for it. This fairly cheap servo gets the job done just fine with these big 2.2 tires. Again, it's the ECO Power WP120T servo.
And I found and fixed the 2 speed shifting problem. The cables used to actuate the shifts don't have the ends sealed or capped. So the end frayed and the screw couldn't hold it anymore. Fortunately I already had a new cable laying around so after a few days the truck is ready for more offroading. On the new cable I dipped the ends in plumbing solder to seal them from fraying.
I had the truck all loaded up on my golf cart to do a shakedown run at the nearby track, and the rain started pouring. And the clouds to the north were dark gray for miles. No driving today...
She's dressed up in her Pro-Line attire again. I made some new boatsides out of lexan and painted them blue.
I don't think I've gone more than 3 batteries without something failing. Let's see if I can slowly increase that by finding and solving these little problems.
And I found and fixed the 2 speed shifting problem. The cables used to actuate the shifts don't have the ends sealed or capped. So the end frayed and the screw couldn't hold it anymore. Fortunately I already had a new cable laying around so after a few days the truck is ready for more offroading. On the new cable I dipped the ends in plumbing solder to seal them from fraying.
I had the truck all loaded up on my golf cart to do a shakedown run at the nearby track, and the rain started pouring. And the clouds to the north were dark gray for miles. No driving today...
She's dressed up in her Pro-Line attire again. I made some new boatsides out of lexan and painted them blue.
I don't think I've gone more than 3 batteries without something failing. Let's see if I can slowly increase that by finding and solving these little problems.
Up until now I haven't been very happy with the suspension tune on this. I figured in time I'd get it dialed in, and it's getting there.
The stock shocks come coil sprung with no oil. Any suspension input results in like 5 cycles (compression with rebound again and again). Even small bumps sent the truck bouncing around repeatedly.
The stock shocks also will not hold oil. They leaked a lot once I added some oil to them. Typical RC4WD shocks, no surprise there. I drained the oil back out of those.
So I added the LX bypass shocks. Those hold oil nicely and have working bypass tubes. I put 10WT oil in those. My hope was to keep the suspension motion fast enough to look realistic, but damped enough to perform decently over rough terrain.
I put 10WT (motorcycle fork oil) in those and it was too much damping. The truck could handle big hits, but that was all. Even big hits only had one suspension cycle; compression then rebounds immediately into ride height and stays put. And the suspension lacked small bump compliance. Not very realistic looking.
So I found some 5WT (also fork oil) and tried that. Now I'm getting into the sweet spot. The small bump compliance is there. And when the suspension takes a hit it compresses, rebounds a bit too far, then compresses again slightly as it settles into ride height and stays put. Pretty realistic looking.
I knew I would need some fairly light shock oil for this truck but I didn't think I would need to go down to 5WT. I could probably even go down to 2.5WT and remove some preload from the springs.
I had this old programming box that worked on those Axial ESC / RX 2 in 1 units. It also works on the stock ESC for this truck. So I turned the drag brake way down and increased the punch slightly.
The stock shocks come coil sprung with no oil. Any suspension input results in like 5 cycles (compression with rebound again and again). Even small bumps sent the truck bouncing around repeatedly.
The stock shocks also will not hold oil. They leaked a lot once I added some oil to them. Typical RC4WD shocks, no surprise there. I drained the oil back out of those.
So I added the LX bypass shocks. Those hold oil nicely and have working bypass tubes. I put 10WT oil in those. My hope was to keep the suspension motion fast enough to look realistic, but damped enough to perform decently over rough terrain.
I put 10WT (motorcycle fork oil) in those and it was too much damping. The truck could handle big hits, but that was all. Even big hits only had one suspension cycle; compression then rebounds immediately into ride height and stays put. And the suspension lacked small bump compliance. Not very realistic looking.
So I found some 5WT (also fork oil) and tried that. Now I'm getting into the sweet spot. The small bump compliance is there. And when the suspension takes a hit it compresses, rebounds a bit too far, then compresses again slightly as it settles into ride height and stays put. Pretty realistic looking.
I knew I would need some fairly light shock oil for this truck but I didn't think I would need to go down to 5WT. I could probably even go down to 2.5WT and remove some preload from the springs.
I had this old programming box that worked on those Axial ESC / RX 2 in 1 units. It also works on the stock ESC for this truck. So I turned the drag brake way down and increased the punch slightly.
5 batteries since the last repair and I'm beginning to think I've got most of the bugs worked out. I added a Tekno servo horn because it's super exposed, and I wanted a beefy one to survive abuse. I'd already broken 2 other servo horns.
Those 5 batteries have all included hi-speed / rough terrain and low-speed / high torque driving.
The only thing that seems to need adjustment is a "click" coming from the drivetrain under sudden, heavy loads. It's only one click then it quiets down. I suspect I need to shim the axle pinion gears.
I've never needed to shim pinion gears. I assume you just add washers either to the driveshaft side, or inside of the axle housing on the pinion shaft to keep it where it needs to be. Am I right about that?
Those 5 batteries have all included hi-speed / rough terrain and low-speed / high torque driving.
The only thing that seems to need adjustment is a "click" coming from the drivetrain under sudden, heavy loads. It's only one click then it quiets down. I suspect I need to shim the axle pinion gears.
I've never needed to shim pinion gears. I assume you just add washers either to the driveshaft side, or inside of the axle housing on the pinion shaft to keep it where it needs to be. Am I right about that?
themountain
I joined the Band!
That one "click" could also be the driveshafts...check if there is some play "thumbsup"
If you mean play between the inner and outer sliders, those are almost too tight. The tolerance between those is pretty good. I'm not sure what would click in the driveshaft, but I certainly hope that's it.
I've been fairly hard on this truck in this thread, but there are a few good points to address:
The suspension links are strong and tight. No slop there. The spring rates RC4WD spec'd for these shocks are spot on. The chassis can take a pretty good beating. Both my son and I have put this truck through some pretty hard rolls on rocks, and nothing has broken.
We drove it again today, and once again, nothing broken. The more batteries I go between failures the more fun I'm having with this truck, especially having finally gotten the shocks tuned well.
I've been fairly hard on this truck in this thread, but there are a few good points to address:
The suspension links are strong and tight. No slop there. The spring rates RC4WD spec'd for these shocks are spot on. The chassis can take a pretty good beating. Both my son and I have put this truck through some pretty hard rolls on rocks, and nothing has broken.
We drove it again today, and once again, nothing broken. The more batteries I go between failures the more fun I'm having with this truck, especially having finally gotten the shocks tuned well.
themountain
I joined the Band!
No...I meant the joints of the shafts...the brass bit gets a little sloppy after hard bashing...dont ask how I know that:roll::mrgreen: Great to hear though that it is in general a good rig...besides the axles,of course.
Okay, thanks. I'll probably buy 2 Hero driveshafts from Ottsix to use as replacements for the stock shafts. I assume they're going to fail sooner rather than later.
I've been doing a lot of shifting with this truck. I find the places I really have fun driving it force me to shift from low range (low gear, diffs locked) to high range (high gear, diffs open) and back and forth. I almost never use 2wd though.
I'm starting to wish I had more batteries for this truck. I used to just wish I could make it through one without something failing.
I've been doing a lot of shifting with this truck. I find the places I really have fun driving it force me to shift from low range (low gear, diffs locked) to high range (high gear, diffs open) and back and forth. I almost never use 2wd though.
I'm starting to wish I had more batteries for this truck. I used to just wish I could make it through one without something failing.
Lots of words in this post, and unfortunately no photos. Because my truck doesn't drive at the moment...
My Miller Motorsports truck hasn't seen any updates recently, as I've been working on it for about 3 weeks. That "click" I mentioned in a previous post has gotten progressively worse, as clicks tend to do. Now the truck no longer moves. It just "clicks" as the motor spins, but the driveshafts don't (neither of them).
So I've removed, disassembled, re-installed and tested the transmission. 3 times. And it's A LOT of work to get that transmission out, then its a lot of work to disassemble it. But everything, including the transfer case has been disassembled and reassembled multiple times.
There are no obvious defects in the transmission. All of the gears are in good shape. None of the pins that hold gears in place have sheared. There's no metal chunks or chips in the transmission.
One of the times I disassembled the transmission I found the screws securing the transfer case to the transmission housing loose. I tightened those up, and the click remains.
I also disassembled both axles, which is how I discovered a few problems there. Both ring gears were loose from the differential cups. And the front ring gear had the locking tabs sheared again. This time it was only one tab, not all three. But I tightened up (and Loc-Tited) the ring gear bolts and replaced the front ring gear. And yet the "clicking" remains.
I removed the driveshafts individually, testing each by itself. The click remains with each driveshaft pulling on its own.
So I've given up. I emailed RC4WD asking for any possible directions to look in, but they're currently working through this and don't have an answer yet. Since this problem started before I ever dug into the transmission I'm confident it's not the case that I just incorrectly assembled it.
The last time I had removed the transmission I decided it was so much work, that if I ever had to do it again I was going to swap the motor out for something faster. So I stole the Spektrum 2300KV brushless system from my Bronco and installed it in the Miller Motorsports truck. If I ever get this RC4WD truck working again, it should be more fun to drive.
But that being said, I've considered trying to swap my old Twin Hammers transmission into this. Or even finding a way to put an SCX10.3 transmission in instead. I'd love for this problem to be a one-time thing, but I'm unfortunately not so confident.
My Miller Motorsports truck hasn't seen any updates recently, as I've been working on it for about 3 weeks. That "click" I mentioned in a previous post has gotten progressively worse, as clicks tend to do. Now the truck no longer moves. It just "clicks" as the motor spins, but the driveshafts don't (neither of them).
So I've removed, disassembled, re-installed and tested the transmission. 3 times. And it's A LOT of work to get that transmission out, then its a lot of work to disassemble it. But everything, including the transfer case has been disassembled and reassembled multiple times.
There are no obvious defects in the transmission. All of the gears are in good shape. None of the pins that hold gears in place have sheared. There's no metal chunks or chips in the transmission.
One of the times I disassembled the transmission I found the screws securing the transfer case to the transmission housing loose. I tightened those up, and the click remains.
I also disassembled both axles, which is how I discovered a few problems there. Both ring gears were loose from the differential cups. And the front ring gear had the locking tabs sheared again. This time it was only one tab, not all three. But I tightened up (and Loc-Tited) the ring gear bolts and replaced the front ring gear. And yet the "clicking" remains.
I removed the driveshafts individually, testing each by itself. The click remains with each driveshaft pulling on its own.
So I've given up. I emailed RC4WD asking for any possible directions to look in, but they're currently working through this and don't have an answer yet. Since this problem started before I ever dug into the transmission I'm confident it's not the case that I just incorrectly assembled it.
The last time I had removed the transmission I decided it was so much work, that if I ever had to do it again I was going to swap the motor out for something faster. So I stole the Spektrum 2300KV brushless system from my Bronco and installed it in the Miller Motorsports truck. If I ever get this RC4WD truck working again, it should be more fun to drive.
But that being said, I've considered trying to swap my old Twin Hammers transmission into this. Or even finding a way to put an SCX10.3 transmission in instead. I'd love for this problem to be a one-time thing, but I'm unfortunately not so confident.
hnoroian
Rock Crawler
for the clicking check your bearings in the outer front axle and the knuckle. Look for micro splitting or a loose fitting bearing pocket. Particularly in the side that does not lift when you punch it, I don’t recall which direction it turns.
I wish I could get my hands on the Miller transmission to see how it works. My first guess based on the noise and lack of motion would be the dogs on one of the gears (something shiftable) are either rounded off, broken, or not being held firmly by the shift mechanism, and just skipping instead of locking together. Lots of complexity inside that trans case to give it all the options they included.
Good luck on finding a solution
Good luck on finding a solution
Thanks guys. The transmission will get torn out and disassembled again, but probably next week.
Hopefully I can find a worn pin, or some cracked plastic somewhere.
RC4WD doesn't have any answers, which is expected. Troubleshooting from long distance is basically impossible. But they did offer to send parts to me. Once I have this narrowed down to which parts have failed I'll likely take them up on that.
Hopefully I can find a worn pin, or some cracked plastic somewhere.
RC4WD doesn't have any answers, which is expected. Troubleshooting from long distance is basically impossible. But they did offer to send parts to me. Once I have this narrowed down to which parts have failed I'll likely take them up on that.
Progress! Some at least...
After a lot of tinkering, testing and frustration I think I discovered the fault. There is a plastic housing which supports the transmission input gear. That housing has a crack in the top that only appears under load. That crack is allowing the transmission input gear to move away from the pinion gear, and then snap back loudly, hence the "click."
The crack is still difficult to see in the photo, but trust me, it's there! I inserted pliers to apply some force and hopefully make the crack visible. It's completely invisible without applying force.
Having realized this, I think I know why it occurred. The screws securing the motor plate to the transmission housing must have loosened up. That allowed the motor plate to flex away from the transmission housing under load. That flexing caused the pinion to push down on the transmission input gear, which is why the crack likely occurred.
So the the likely solution here is a new transmission input gear housing. I've asked RC4WD to send me one. If they don't, I'll just buy one from RPP. The prevention is keeping the upper motor plate screws as tight as possible. They're coarse thread screws, biting into soft plastic. So they're just going to come loose eventually. On mine, I'm replacing those with a thru-bolt and nylock nut. My thru-bolt method only works since I've removed the scale engine housing. If you keep the engine, you're stuck with the coarse thread screws. Fortunately the scale engine housing doesn't fit over the Spektrum 2300KV motor I'm using anyway.
After a lot of tinkering, testing and frustration I think I discovered the fault. There is a plastic housing which supports the transmission input gear. That housing has a crack in the top that only appears under load. That crack is allowing the transmission input gear to move away from the pinion gear, and then snap back loudly, hence the "click."
The crack is still difficult to see in the photo, but trust me, it's there! I inserted pliers to apply some force and hopefully make the crack visible. It's completely invisible without applying force.
Having realized this, I think I know why it occurred. The screws securing the motor plate to the transmission housing must have loosened up. That allowed the motor plate to flex away from the transmission housing under load. That flexing caused the pinion to push down on the transmission input gear, which is why the crack likely occurred.
So the the likely solution here is a new transmission input gear housing. I've asked RC4WD to send me one. If they don't, I'll just buy one from RPP. The prevention is keeping the upper motor plate screws as tight as possible. They're coarse thread screws, biting into soft plastic. So they're just going to come loose eventually. On mine, I'm replacing those with a thru-bolt and nylock nut. My thru-bolt method only works since I've removed the scale engine housing. If you keep the engine, you're stuck with the coarse thread screws. Fortunately the scale engine housing doesn't fit over the Spektrum 2300KV motor I'm using anyway.
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right on good find and fix
Wow, nice troubleshooting. Invisible cracks...
Any ideas why it would have cracked?
Any ideas why it would have cracked?
Thanks.
I suspect the flexing of the motor plate resulted in the pinion gear moving up. This upward movement put either upward or (somehow) downward force onto the the transmission input gear.
The transmission input gear then moved down (or up maybe) cracking the housing which supported it.
It appears to be a very unlikely part to fail, so I really doubt the plastic just failed on its own.
Either way, RC4WD is sending me a whole new transmission; gears, housing and all.
I suspect the flexing of the motor plate resulted in the pinion gear moving up. This upward movement put either upward or (somehow) downward force onto the the transmission input gear.
The transmission input gear then moved down (or up maybe) cracking the housing which supported it.
It appears to be a very unlikely part to fail, so I really doubt the plastic just failed on its own.
Either way, RC4WD is sending me a whole new transmission; gears, housing and all.
ya never know its rc3wd afterall lol
You need some upgraded materials in parts. Are you beating on it pretty hard? I Anyway to build in supports to alleviate the stress on that housing?
An aluminum motor plate would definitely help. But I don't have the means to make that.
Fortunately I can strengthen the motor plate / transmission housing connection by adding hardware (thru-bolts). That should prevent future flexing of the motor plate.
And no, I definitely don't beat on this, or any of my trucks. Realistic driving is what I enjoy, so jumping houses (even toy houses) isn't my thing.
But I did let Kevin Talbot borrow it for a few weeks...
Fortunately I can strengthen the motor plate / transmission housing connection by adding hardware (thru-bolts). That should prevent future flexing of the motor plate.
And no, I definitely don't beat on this, or any of my trucks. Realistic driving is what I enjoy, so jumping houses (even toy houses) isn't my thing.
But I did let Kevin Talbot borrow it for a few weeks...
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Kevin Talbot, lmao. As far as I can tell all he does is take his rigs to the skate park and launch the quarter pipe at full throttle.
By no means am I implying that you mistreat your stuff. I am guilty of running lines that will drop my crawlers hard enough to break rod ends should I flip backwards. I am just trying to gage the level of stress on that part.
