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  1. #1
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    Flipping over when in reverse

    Ive got a slash 4x4 hcg that i bought used. when in reverse and make any amount of turn i lose control (fish tailing in reverse) and flip over. i'm probably doing 5mph when it happens. i cant imagine this is normal. i don't have any real handling problems going forward. Has anyone experienced this or have any advise for me?

    my personal thought is that i need to put in new shock oil in the front because they are really easy to move up and down. the rear have a different set of shocks and are much stiffer.

    Thanks!

  2. #2
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    Yea new oils all around, and sway bars will help. What motor/esc do you have in it?
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  3. #3
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    Quote Originally Posted by ManDime View Post
    Yea new oils all around, and sway bars will help. What motor/esc do you have in it?
    I just ordered sway bars... so i hope it does help. i have the stock esc and motor in it. stock tires too. Im going to convert it to a MT setup. Ive got the proline extended body mount and raptor body. i ordered a set of 2.8 trenchers too. hopefully i can get this issue corrected before i put bigger tires on it because i imagine it would make the problem even worse.

  4. #4
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    Bigger tires will actually make the truck much more stable. Its how narrow the slash tires are how high the CG is that affects balance in turns. And most vehicles with a high CG will flip when in reverse and turning.
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  5. #5
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    Quote Originally Posted by ManDime View Post
    Bigger tires will actually make the truck much more stable. Its how narrow the slash tires are how high the CG is that affects balance in turns. And most vehicles with a high CG will flip when in reverse and turning.
    Bigger as in wider tires? Could you suggest any tires that would make it more stable? Thanks!

  6. #6
    RC Qualifier traxxasvxlbasher's Avatar
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    Like 2.8 trenchers
    | Slash 4x4 | Stampede 4x4 | E-Revo BL | RPM |

  7. #7
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    Quote Originally Posted by MiniElmo View Post
    Bigger as in wider tires? Could you suggest any tires that would make it more stable? Thanks!

    I don't know any tires that will permanently fix this problem but I know if you lower your CG then you should be able to do whatever type of driving you want. I think the traxxas lcg kit will make it much more stable than most wheels. and it will handle better so you can go to the track with SC wheels if you want.
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  8. #8
    RC Turnbuckle Jr. El Sob's Avatar
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    May i ask a question? Does your truck swing side to side violently? The faster you go, the worse it gets? If that is the case, it is your front end alignment.
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  9. #9
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    Yeah it does swing back and forth violently. Its like the front end is too loose. I have a 10 second video. It looks like i'm turning the wheels on purpose but it's doing it by itself.

    https://www.youtube.com/watch?v=5KxSrp3aRcM

  10. #10
    RC Champion skmfkr's Avatar
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    ive seen 2wd vehicles do the wheels back and forth but not a 4wd.

  11. #11
    RC Qualifier Silly Old Boy's Avatar
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    Your truck looks so small in the video. That is one weird wobble.

  12. #12
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    Quote Originally Posted by BigEd87 View Post
    Yeah it does swing back and forth violently. Its like the front end is too loose. I have a 10 second video. It looks like i'm turning the wheels on purpose but it's doing it by itself.

    https://www.youtube.com/watch?v=5KxSrp3aRcM
    Let me guess: You run the stock servo saver / bellcrank?

    I had the same before I installed the STRC alu bellcrank on my Stampede 4x4. The stock servo saver is made quite weak on purpose to protect the plastic gears in the stock servo. If you adjust the front wheels to a slight toe-out, it will run more stable in reverse (but will be more unstable going forward). You can also put a washer on top of the servo saver spring to tighten it a little (a plastic body washer cut to shape will do), but that will increase stress on the servo.
    I solved the issue by installing the STRC alu bellcrank and a stronger, metal geared servo.

  13. #13
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    Quote Originally Posted by Viking View Post
    Let me guess: You run the stock servo saver / bellcrank?

    I had the same before I installed the STRC alu bellcrank on my Stampede 4x4. The stock servo saver is made quite weak on purpose to protect the plastic gears in the stock servo. If you adjust the front wheels to a slight toe-out, it will run more stable in reverse (but will be more unstable going forward). You can also put a washer on top of the servo saver spring to tighten it a little (a plastic body washer cut to shape will do), but that will increase stress on the servo.
    I solved the issue by installing the STRC alu bellcrank and a stronger, metal geared servo.
    Okay, makes sense. Do you recommend any specific servo? Thanks!

  14. #14
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    Savox 1258tg is da best...
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  15. #15
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    Wow, that vid looks like you are turning the steering back and forth. Hope you get it resolved.
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  16. #16
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    Quote Originally Posted by BigEd87 View Post
    Okay, makes sense. Do you recommend any specific servo? Thanks!
    Sorry it took a while to get back to you.

    There are dozens of servos out there, and it's hard to pick one. Since you got a HCG I assume you don't race. For a basher you probably won't have the need for a super fast servo, but more torque than stock is always nice. Does it have to be wateproof?. Waterproofing a servo is very easy using Plastidip and/or liquid tape. Price range?

    Savox servos are great but amp hungry, so in many cases you'll need an external BEC to run them (especially with the MMP).
    I was going to get a Hitec HS-5585MH but endend up with a Hitec HS-7985MG instead (got a great deal on it). I waterproofed it myself and I'm very happy with it. Having no problems running it on the VXL-3s without any glitching.

  17. #17
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    well bad news. put the new strc bellcrank (followed ElSob's advice and didnt tighten the saver spring down very much) on but still am using the stock servo and tested it with the exact same result. on the bright side i've upgraded the bell crank but just don't understand what the problem is. i recorded a new video with the body off. really bummed that didnt fix it... again it looks like im steering this back and forth but all i did was start turning a little bit and then let off. if i would have hit the throttle harder it would flip.

    https://www.youtube.com/watch?v=nhWQvzI_XLo

    whats next to upgrade?
    Last edited by BigEd87; 07-16-2014 at 10:52 PM.

  18. #18
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    <Bump>

    Does anyone have an idea what might be causing this?

  19. #19
    RC Turnbuckle Jr. billy-bones's Avatar
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    I didn't read all the above post so please excuse me if I'm repeating.
    Have you tried adjusting your toe in and or out?
    It looks as if your front tires are towing way out in reverse.
    It also looks like the tires are physically turning as well, possibly a weak servo or radio interference.
    These are just a few ideas as I'm not certain of what it could be.
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  20. #20
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    thanks for your reply. i put my axial ae3 servo in it because it has a little more torque and metal gears. i also adjusted my front end toe. it was toe out so i changed it to a bit of toe in. it is better but not gone. can the stock 2075 servo get weaker over time? is this normal for the slash 4x4? i bought this used so i have nothing to compare it to. my mini summit has no strange issues when in reverse.

  21. #21
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    Quote Originally Posted by BigEd87 View Post
    thanks for your reply. i put my axial ae3 servo in it because it has a little more torque and metal gears. i also adjusted my front end toe. it was toe out so i changed it to a bit of toe in. it is better but not gone. can the stock 2075 servo get weaker over time? is this normal for the slash 4x4? i bought this used so i have nothing to compare it to. my mini summit has no strange issues when in reverse.
    I've honestly never ran a stock servo long enough to know it they weaken performance wise, nor have I tried any real reverse moves, none causing your issue least ways.
    It really appears to be a combination of to much toe and a physical involuntary servo movement.
    I wish I could be more help but I'm amiss for an answer.
    Do you have the stock tires, perhaps see if they do it as well.
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  22. #22
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    Its probably not this but have you checked to make sure the servo and speed control are plugged in the correct slots on the receiver. I had mine plugged in wrong one time and it was doing some strange stuff like making the servo flutter when you acclerated
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  23. #23
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    I have the same problem after 1 years of continuous use (average of several packs a week):
    https://www.youtube.com/embed/MzlrBfybjUM
    I upgrade:
    - Sav÷x SC-1258 TG (reduce a little)
    - STRC steering with "strong" screwing of the spring (reduce a little more)
    - RPM end-toes to reduce play + reduce weight by putting off the roll cage + change all screws, axles, bulkhead and A-arms to reduce the "play" + reduce opening angle: it reduce a lot now, but when I use 2.8 Trenchers, it reappears.
    For me it comes from the "play" everywhere and big wheels increase it, maybe because of bigger diameter.
    Last edited by Phenix2984; 07-21-2014 at 02:00 AM.

  24. #24
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    I forget and dont find the "edit" button: I increase also the voltage of the servo to 6.0VCC to have more torque on the Sav÷x.

  25. #25
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    Yeah I've pretty much given up on fixing this issue. I'm going to crank down the servo saver since I have a metal gear servo in it now. I'm curious how you adjusted your servos voltage though?

  26. #26
    RC Turnbuckle Jr. billy-bones's Avatar
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    Quote Originally Posted by BigEd87 View Post
    Yeah I've pretty much given up on fixing this issue. I'm going to crank down the servo saver since I have a metal gear servo in it now. I'm curious how you adjusted your servos voltage though?
    You cant on the stock system, you need a castle, tekin or other brand which allows for this.
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  27. #27
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    Quote Originally Posted by BigEd87 View Post
    I'm curious how you adjusted your servos voltage though?
    Quote Originally Posted by billy-bones View Post
    You cant on the stock system, you need a castle, tekin or other brand which allows for this.
    Exact, I've MMM v3, You can set it with castle link.
    Most of the servo have more torque when increasing the voltage.

  28. #28
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    Especially with an aluminum bell crank, I don't see how it's possible for toe in/out in the front to cause THAT much wiggle. It seems to be turning full lock to lock on you. That feels more like radio weirdness. If you pick the car off the ground and go in reverse, do the wheels turn or stay straight?

    Do you have another radio system from another car you can swap in? If not, unplug the steering servo from the receiver and try driving in reverse. If it still does it then it's not the radio. If it doesn't, then you know the problem is electrical and not mechanical. While the stock servo may not be the greatest, I've found it to be perfectly adequate even with trencher 2.8s and a relatively heavy truck with lots of aluminum, so unless you're racing there's no immediate need to replace it unless you break it.
    Last edited by Trisk; 07-22-2014 at 06:45 AM.

  29. #29
    RC Turnbuckle Jr. El Sob's Avatar
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    Billy was right when he said your alignment is off. You can put new servos and bell cranks in your truck and problem will be there. You need to straighten your front wheels out some. Tighten both sides a little at a time and measure how close they are getting. If you can get them so they a just slightly toed out, you will be rid of this problem. I have had this problem in the past.
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  30. #30
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    Thanks for the replies. This doesn't happen when off the ground so to me that means it'smech anical. I have a spare traxxas transmitter but not a new receiver.

    Regarding alignment, what is your suggestion for the distance apart? I guessI sh ouldbuy one of those toe guages.

  31. #31
    RC Turnbuckle Jr. El Sob's Avatar
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    Best advice is to get a tape measure. I usually keep mine no more than1/8 inches wider in the front than the back.
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  32. #32
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    What is the oil in your front shocks? If they're super soft that might also contribute to this.

  33. #33
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    I used to work at a golf course taking care of the carts. ALL of the carts we had would do this when given power in reverse without holding on to the steering wheel. Not sure why, but when the same thing happened to my slash, I didn't think anything of it! Seems like something in the alignment probably. Defiantly nothing electrical.

  34. #34
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    I think too many toe-out angle + to much play in the bellcranck and A-arms.
    As the problem increase when I put bigger wheels, it's logic for me.

  35. #35
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    Yeah it still occurs with the stock tires. I've adjusted the toe angle again and it helped a bit. I'm wondering if the play in the front wheels is normal. Here's the vide. Tha nks for the helphttp://youtu.be/onYhpYODqxc

  36. #36
    RC Turnbuckle Jr. billy-bones's Avatar
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    Quote Originally Posted by BigEd87 View Post
    Yeah it still occurs with the stock tires. I've adjusted the toe angle again and it helped a bit. I'm wondering if the play in the front wheels is normal. Here's the vide. Tha nks for the helphttp://youtu.be/onYhpYODqxc
    I put a battery in the platinum today, I have to run the 4wds once in a while, lol.
    I noticed it produced the same results in reverse as yours, the slightest steering input provided an exaggerated response which increased with speed.
    I truly believe it has to do with the rear tires being toed 3 in degrees with the fronts toe slightly reversed.
    It acts as if your driving forward with the front tires toed in to far creating extreme over steer.
    Running forward the rear tires are fixed maintaining straight forward movement, however in reverse the front wheels give to the slightest miss alignment.
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  37. #37
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    Quote Originally Posted by BigEd87 View Post
    Yeah it still occurs with the stock tires. I've adjusted the toe angle again and it helped a bit. I'm wondering if the play in the front wheels is normal. Here's the vide. Thanks for the help http://youtu.be/onYhpYODqxc
    Same for me before.
    Reduced by changing the rod ends and ball bearing.
    I think most of the slash have this problem after some times, but nobody drive forward

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