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  1. #1
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    Unhappy Engine Starts but Truck Will Not Drive HELP!!!

    So I bought a T-maxx 2.5 off of eBay. The truck starts up and runs just fine, but when I give it only a little bit of gas it jumps forward slightly, but mostly just revs in neutral. If I punch the gas the truck takes off and drives fine. I do not want to drive it like this, in case I'm hurting the trans. Any help?

  2. #2
    RC Turnbuckle Jr. Wildman4910's Avatar
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    The 4910 2.5 maxx w/reverse all "Buck" when slowly giving them throttle, it's normal because of how the transmission is designed.

    You can get rid of reverse for FOC(Forward Only Conversion) #4994X or you can live with the "Bucking", or you can do the "No Buck Mod" if you want to keep reverse & not have it "Buck".

    FOC #4994X
    http://buy.traxxas.com/product_info....oducts_id=7315

    No Buck Mod how to below.
    http://traxxas.com/forums/showthread...y-modification

    I put the FOC in my maxx & couldn't be happier with it.
    In my wifes maxx I did the no buck mod & it works well.
    Last edited by Wildman4910; 08-27-2012 at 11:33 PM.
    Look out for the tree/crunch!

    LiPo? Naw NITRO!!

  3. #3
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    Hey thanks for the response! The FOC is out of stock or else i would have ordered it on spot . I think mine is "bucking" a lot more than usual though. The spur gear also spins extremely fast when just idling. I don't recall if it supposed to do this or not though.

  4. #4
    RC Turnbuckle Jr. Wildman4910's Avatar
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    At idle the engine clutch shouldn't be engaged.

    Pop the E~clip off the bell & check the clutch spring. Do not loose the teflon washer that goes behind the E~clip.

    RCPlanet.com has them.
    http://www.rcplanet.com/SearchResult...&Submit=Search
    http://www.ebay.com/itm/Traxxas-4994...item4168e84b1c
    http://www.ebay.com/itm/T-maxx-Forwa...item564be597ae
    Look out for the tree/crunch!

    LiPo? Naw NITRO!!

  5. #5
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    OK I ordered the FOC. In a little bit I'll put up a video on YouTube and link it to you of what it's doing. And of course the bell clutch is insanely hard to access.

  6. #6
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    Also I made a video showing the problem. Here it is: http://youtu.be/F9gizLftkFw

  7. #7
    RC Turnbuckle Jr. Wildman4910's Avatar
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    The bucking you see is normal, the engagement pawl has to overcome the spring pressure to catch the pin in the shift drum.

    It is idling really high & needs retuned.

    I would think the engine clutch is good after seeing the video, since you have to pull the trany to do the FOC it can't hurt to pull the bell & have a looksee at the clutch.

    Check the slipper, it seems like it may be loose or need new friction pegs, pegs should stick out of spur gear slightly, if they are flush to the spur or melted into the spur it's time to replace, when replacing the pegs put all 12 in the spur.

    To check set the slipper tighten the nut down tight then back it off 1/4 turn.

    It may be loose or need new pegs.
    Look out for the tree/crunch!

    LiPo? Naw NITRO!!

  8. #8
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    Thanks for the help man! I'm actually going to take it to my local hobby shop on friday because I am out of gas anyway. While I'm there I'm just going to ask them to tune it for max performance and maybe install the FOC and inspect everything, that is if it comes in time. I thought it was idling pretty high, but wasn't sure because I've never had a T-maxx before. Despite my troubles, I am still in love with this truck!

    Also just wanted to say that this forum is awesome! Very quick responses and it seems like everyone really knows what they're talking about.

  9. #9
    Marshal Double G's Avatar
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    Best thing to do is work on the truck yourself. The LHS will charge you decent money yet I have issues with others touching my truck. Learn how your truck works and do it yourself. These things are pretty simple to work on if you are okay working with your hands.
    And for the tuning, they could tune it for optimum performance that day--or even that hour depending on the temperature/humidity change--but what about the next or days thereafter? Learn from them how to tune then spend some time in a big lot and learn some more.
    The Super Derecho

  10. #10
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    I know what you mean, but as of right now its pretty out of whack. If they could get it and a decent stable tune I would have no problem adjusting it here and there. Plus it's only 10 bucks to get it tuned. As for the FOC, ill probably put it on myself, I just don't know how.

  11. #11
    RC Turnbuckle Jr. Wildman4910's Avatar
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    Quote Originally Posted by BeautifulKyle View Post
    As for the FOC, ill probably put it on myself, I just don't know how.
    Stupid easy to do, & comes with very easy to follow instructions.
    Look out for the tree/crunch!

    LiPo? Naw NITRO!!

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