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  1. #1
    RC Turnbuckle Jr. olds97_lss's Avatar
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    Heavy duty cold weather arms splitting at the seam on my stampede 4x4...

    So far, I've had 4 of the HD cold weather arms split at the seam on the hinge pin end of the arm. One on the rear and 3 on the front. I know I push my stuff pretty hard, but it seems a bit excessive to have one break nearly every time I run the truck. Wouldn't be as bad if they were interchangeable with right/left, but I now have 4 spare right arms and no lefts.

    I went back to my old RPM arms on the front for the time being. I know they are like having a wet noodle... but I'd like to be able to make it through a single pack for a change.

    Was curious if others are having issues with these arms or not.
    https://www.youtube.com/c/olds97lss

  2. #2
    RC Racer GTSDart340's Avatar
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    Quote Originally Posted by olds97_lss View Post
    So far, I've had 4 of the HD cold weather arms split at the seam on the hinge pin end of the arm. One on the rear and 3 on the front. I know I push my stuff pretty hard, but it seems a bit excessive to have one break nearly every time I run the truck. Wouldn't be as bad if they were interchangeable with right/left, but I now have 4 spare right arms and no lefts.

    I went back to my old RPM arms on the front for the time being. I know they are like having a wet noodle... but I'd like to be able to make it through a single pack for a change.

    Was curious if others are having issues with these arms or not.
    Are you talking about the wheel end? If so, I have one that's done that in my Rustler 4x4. It split on the non threaded side of the pin. I ended up using super glue and switching the threaded side over while I had it clamped together. So far it's holding up. It's had some pretty hard crashes, and no issues yet. I'm too cheap to buy new parts until I have to.

    Rustler 4x4 VXL

  3. #3
    RC Turnbuckle Jr. olds97_lss's Avatar
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    No, mine have all broken on the inside end where it connects to the bulkhead. I have the wheel end captured on both sides with a 3.2mm pin and collars vs threading into it from one side.

    https://www.youtube.com/c/olds97lss

  4. #4
    RC Champion Panther6834's Avatar
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    I think he's referring to the end that connects to the bullhead, not the caster/carrier blocks. If so, I've also had it happen. In my case, in it was at the front. I hit a brick (the mini curved bricks that people use to outline their lawns), the A-arm split right at the hinge pin, and the arm "detached" from the bullhead.


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  5. #5
    Traxxas Marshal
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    Have you tried contacting Traxxas support? Perhaps there was an issue with a run of these parts?
    "Happiness depends upon ourselves." -Aristotle

  6. #6
    RC Turnbuckle Jr. olds97_lss's Avatar
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    Quote Originally Posted by cooleocool View Post
    Have you tried contacting Traxxas support? Perhaps there was an issue with a run of these parts?
    No, I haven't. Figured I'd ask on here to see if others have been having an issue.

    Not sure why, but I forgot to post a photo of at least one of them before:


    I put a small awl in it so the split is visible. All 3 broke the same way.
    https://www.youtube.com/c/olds97lss

  7. #7
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    I'd shoot them an e-mail. Worst case, nothing comes of it. Best case, maybe you help identify a potential issue with a run of the arms.
    "Happiness depends upon ourselves." -Aristotle

  8. #8
    RC Turnbuckle Jr. olds97_lss's Avatar
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    I did. Sent them the photo and link to this thread as well. Not sure anything will come of it.

    I switched back to my old RPM arms for the time being on the front.
    https://www.youtube.com/c/olds97lss

  9. #9
    RC Champion Panther6834's Avatar
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    Quote Originally Posted by olds97_lss View Post
    I did. Sent them the photo and link to this thread as well. Not sure anything will come of it.

    I switched back to my old RPM arms for the time being on the front.
    As a "backup" to the email, I'd give them a call. When it comes to Traxxas (and Horizon Hobby, for that matter), I've always gotten great CS over the phone. As long as they're not "short" on time, or super busy, they're usually more than happy to help customers resolve problems.

    I haven't had any neeed to call them in quite some time...but, approx 2yrs ago, when I was having some major Tx/Rx/ESC problems, the person helping me not only did whatever he could to help resolve the problem, but he happily walked me through everything, step-by-step, trying different things, until the problem was resolved.

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  10. #10
    RC Racer GTSDart340's Avatar
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    Quote Originally Posted by olds97_lss View Post
    No, I haven't. Figured I'd ask on here to see if others have been having an issue.

    Not sure why, but I forgot to post a photo of at least one of them before:


    I put a small awl in it so the split is visible. All 3 broke the same way.
    Funny, my arm broke exactly the same way but on the other end! In the picture you can see I've tried to glue it without success...

    Rustler 4x4 VXL

  11. #11
    RC Turnbuckle Jr. olds97_lss's Avatar
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    If it happened just once, or after a very long time, I wouldn't think much of it. But I've broken one almost every time I've run the truck since I installed them, which made me question the part a bit.
    https://www.youtube.com/c/olds97lss

  12. #12
    RC Turnbuckle Jr. olds97_lss's Avatar
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    They replied saying they haven't had many people asking about the issue, so I guess it's just my bad luck. They are sending me a pair of replacement orange arms when they have some in stock anyway.

    Guess I'll stick with RPM for now and live with the fact that they absorb a lot of the force not allowing my sway bars and shocks do their jobs properly.

    If it only happened when I ran the larger 3.8 wheels or 4S, I'd chalk it up to "asking too much from it", but it happened also when running 3S with 2.8" tires. Just kind of annoying... 4 bash sessions, 3 broken arms in the same spot.
    https://www.youtube.com/c/olds97lss

  13. #13
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    I left mine stock for 7 years never broke one so ya

  14. #14
    RC Turnbuckle Jr. olds97_lss's Avatar
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    Quote Originally Posted by Big androski View Post
    I left mine stock for 7 years never broke one so ya
    I lasted a few months when I got mine used, broke a couple stock ones, then ran RPM after that.


    Don't recall breaking an RPM over 3 years use or so, they would just get white spots near the shock mount from bending too much and I'd replace them before they broke.


    I think I put 3 sets of RPM on them over the 3 years I ran those. Usually a new set in the Spring and I was good until the next Spring.
    https://www.youtube.com/c/olds97lss

  15. #15
    RC Turnbuckle Jr. olds97_lss's Avatar
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    Well... the old RPM arms held up. I think I'm going to ditch the sway bar. I like it, but it has interference with the upper turnbuckles on the front and rear. I may put them back if I get some different threaded rod to use longer links to connect them.

    I ripped the front RPM tower out of the bulkhead and broke the top off the front of the bulkhead... not sure when I did it, but found the damage when I got home. I only noticed it steering poorly, which appears to be my HR servo saver nut backed off, so it was absorbing almost all of my servo torque.

    Got parts on order to replace the front tower/bulkhead. I finally made it through one full 4S pack. I did fry a spur though, first time I've done that in a while. I don't think I had the mesh quite tight enough. About half way through my second pack (after installing a new spur), is when I noticed the bad steering. Not sure if my tower/bulkhead was ripped off at that point or not.
    https://www.youtube.com/c/olds97lss

  16. #16
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    Quote Originally Posted by olds97_lss View Post
    I finally made it through one full 4S pack. I did fry a spur though,. . .
    Doesn't sound like you made it if you took out a spur on your first pack and the tower/bulk on the second!
    "Happiness depends upon ourselves." -Aristotle

  17. #17
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    Have you thought of reinforcing them a little - possibly drill 1mm holes and then use stainless safety wire to wrap around knuckle - see pic



  18. #18
    RC Turnbuckle Jr.
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    Quote Originally Posted by olds97_lss View Post
    Well... the old RPM arms held up. I think I'm going to ditch the sway bar. I like it, but it has interference with the upper turnbuckles on the front and rear. I may put them back if I get some different threaded rod to use longer links to connect them.

    I ripped the front RPM tower out of the bulkhead and broke the top off the front of the bulkhead... not sure when I did it, but found the damage when I got home. I only noticed it steering poorly, which appears to be my HR servo saver nut backed off, so it was absorbing almost all of my servo torque.

    Got parts on order to replace the front tower/bulkhead. I finally made it through one full 4S pack. I did fry a spur though, first time I've done that in a while. I don't think I had the mesh quite tight enough. About half way through my second pack (after installing a new spur), is when I noticed the bad steering. Not sure if my tower/bulkhead was ripped off at that point or not.
    I should’ve mentioned I run steel spurs in all my rides. And yes for everyone, I understand the risks involved.
    Sounds like quite a session, fun times fixing things.


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  19. #19
    RC Champion Panther6834's Avatar
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    Quote Originally Posted by Gripdog7205 View Post
    I should’ve mentioned I run steel spurs in all my rides. And yes for everyone, I understand the risks involved.
    Sounds like quite a session, fun times fixing things.


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    First, I should mention that I rechecked the vehicle in question (although the accident happened many months ago, I didn't get around to starting the repair until just last night, as my focus had been on other multiple vehicles & FE boats), and I do need to report that what I previously stated was incorrect. My broken A-arm was not at the front, nor was it on the inside. Upon pulling it out from its carrying case, I discovered that...exactly as those by others, mine is ALSO at the rear, and it is ALSO on the outside. This leads me to believe that, whether (or not) Traxxas is acknowledging this as a problem, it truly could be a problem.

    The "steel vs plastic spur" debate has been growing again. There's been a few threads created on the matter recently...two (that I know of) within the Traxxas forum, and at least one within the RC Groups forum. There might be others in other forums. Something directly connected to this debate is the "slipper vs center differential" debate, primarily because, by going with the center diff (TRA6780), you have no choice but to use a steel spur. I don't mention this because of the broken A-arm matter of this thread...but, at the same time, there could be a possible connection.

    As everyone using a plastic spur & steel pinion knows, that is one of the two "weakest link" points....the other would be the stock plastic driveshafts. For those having replaced the plastic driveshafts with the Traxxas CVDs, or Tekno M6s, you are left with the plastic spur being the "weakest link"...and, this is all for a very valid reason - if ANYTHING happens asking the drivetrain, the spur will be what 'gives'. Plus, it's the cheapest part in the drivetrain, thus is consider that a "benefit". At the same time, for anyone using a steel spur, or center diff, you've removed that "weakest link" point, thus another point MUST because the "weakest link".

    Well, the truth is, the plastic spur (and stock plastic driveshafts, for those still using them) are NOT the only "weakest link" points...the A-arms are also a part of that category, as the plastic at both ends (where the pins go through) is on the somewhat thin side...especially on the 'outside' end. Additionally, when comparing the 'inside' and 'outside' ends, the 'outside' end WILL experience more force - the 'inside' end only experiences up/down movement, while the 'outside' end experiences up/down movement AND twisting movement...and, that is what is probably causing the problem we've been experiencing.

    I'm sure there will be some who might want to disagree with me on what I'm about to say, but I ask you to first think through all I've said, combined with what I'm about to say. Traxxas probably doesn't consider this a "problem" because it's part of the "design". There are plenty of other parts that, if damaged, would be more costly to replace. As previously mentioned, the spur is one of the cheapest parts to replace. If there's any serious binding on the drivetrain, the teeth on the spur should break off, thus "saving" the rest of the drivetrain (including the motor).

    Thinking along these lines, let me ask everyone a question: If any of the four 'axles' are reaching the point of binding, which part would you prefer to have break? The driveshafts? Probably not, as they're somewhat more costly to replace. The carrier and/or steering block? Also 'probably not'...not only because of the replacement cost of those parts, but also because you'd probably have to also replace the bearings (which would have probably gotten lost). Within this area, the most 'logical' part to have a "weakest link" designation, and have to replace, would be the A-arms. And, where that break is bound to occur is where the carrier, or steering block, attaches to the A-arm. In almost all cases, the pin will still be retained by the carrier/block, thus the only part needing replacement is the A-arm.

    We get into this hobby KNOWING that parts will get broken, thus we'll have to replace them. If we wanted "nothing broken", we'd build plastic models, place them on our shelves, and look at them...but, we prefer to actually drive our "models", thus we buy, and run, RC vehicles. In doing so, we also accept the fact that replacement parts will be needed, thus costing more money. Personally, I'd rather have to occasionally replace spur gears, and A-arms, than more expensive parts.


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  20. #20
    RC Champion Panther6834's Avatar
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    Final finished removing the broken A-arm, and was able get a really good look at it...again, mine was NOT from the front, and was NOT the inside. Like others, mine WAS from the rear ("passenger" side), and it WAS the outside. However, unlike the 'problem' reported by others having experienced this, the breaking on mine was on BOTH sides - the 'screw' side is clean-through, while the other said is only partially "ripped".
    Instead of going with the RPM arms (which I find far too flexible), or the 'standard' Traxxas arms, I've decided to give the Pro-Line ProTrac (from the ProTrac Suspension Kit) arms a try. I know they're slightly longer, which would normally require using the included Pro-Line wheels (sure to the different offset), and also requires using longer turnbuckles (also included in the Suspension Kit), but I think I might actually like the slightly-wider rear (using the same wheels I was already using. If I were running a Slash-width body, if could prove problematic...but, since I'm using a narrower (NOT Rustler) body, it won't be a problem.


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  21. #21
    RC Racer GTSDart340's Avatar
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    Same place mine broke. Right rear outer end. I agree though, it could be a weak spot on purpose. I'd definitely rather replace the arm than the whole differential housing!

    Rustler 4x4 VXL

  22. #22
    RC Turnbuckle Jr. olds97_lss's Avatar
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    Quote Originally Posted by cooleocool View Post
    Doesn't sound like you made it if you took out a spur on your first pack and the tower/bulk on the second!
    I replaced the spur, then finished the pack. Then ran the second pack to LVC. I didn't notice the bulkhead issue until I got home... but it was steering poorly. lol!
    https://www.youtube.com/c/olds97lss

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