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  1. #1
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    Open differential question

    Wondering how many have changed the differential to the open mod, I've only seen some on YouTube but they don't test it very much. Wondering if any one would have feedback pro's/con's.

    Thank you

  2. #2
    RC Champion RCWilly's Avatar
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    Traxxas has the rear diff for the UDR, so no mod is needed to make the rear open (I'm pretty sure the videos were made before the full rear differential was released):

    https://traxxas.com/products/parts/8576
    Everyday's a gift, thus now is called the present.

  3. #3
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    RCWilly,

    I new to this so bear with me, will this diff rear that you linked reduce the roll overs, I was trying to read up on it to help reduce rollovers.

    Thanks for your time

  4. #4
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    Rc Wiley, Mod means modification

    I have not trued the diff mod but Iíll bet it will make it handle great.
    Last edited by Ikemort; 02-22-2021 at 03:18 PM.

  5. #5
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    Sorry guys for the questions, will the rear diff that RCWilly linked too act as an open diff like the videos?

    This is what I'm trying to achieve

    https://www.youtube.com/watch?v=3yNuJnXarWY

  6. #6
    RC Champion RCWilly's Avatar
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    Quote Originally Posted by firemedicUSAR View Post
    RCWilly,

    I new to this so bear with me, will this diff rear that you linked reduce the roll overs, I was trying to read up on it to help reduce rollovers.

    Thanks for your time
    I haven't installed it on mines, but the rear differential will definitely help reduce rollovers when turning.
    Everyday's a gift, thus now is called the present.

  7. #7
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    RCWilly,

    Thank you for your help, have you added different sway bars or adjusted the shock oil weight?

  8. #8
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    I have 70 weight shock oil in the rear and 40 in the front and no sway bars and mine handles fine. And it is a cheap mod

  9. #9
    RC Champion RCWilly's Avatar
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    Quote Originally Posted by firemedicUSAR View Post
    RCWilly,

    Thank you for your help, have you added different sway bars or adjusted the shock oil weight?
    I did not adjust the sway bars or shock oil, since I liked how it handles stock, but thicker shock oil and stiffer springs will help make it more stable at higher speeds (too thick could be detrimental as well, so find a happy medium for your setup).
    Everyday's a gift, thus now is called the present.

  10. #10
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    The open diff helps the truck from rolling over as much. More so if you're on pavement or hard packed ground. I think it's worth it.

    I recently swapped the front sway bar as I was running in sand more often, and I will say that made it much more sketchy on pavement. In the soft it helps to rotate the truck, but on pavement it's much more difficult to keep it straight.

    I'd pass on the sway bar and go for the diff.

  11. #11
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    I switched to the open diff...and its so easy...and its awesome....drifts....powerslides.....drives awesome...you won't regret doing it....easy to do.

  12. #12
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    Unfortunately the area I live I mostly run on street, yards and football fields. I'm gonna switch to the open diff, do you guys have any recommendations on grease?


    Thank you to all that replied, I truly appreciate it!

  13. #13
    RC Champion RCWilly's Avatar
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    I think the differential comes filled with silicone fluid, not completely sure about the viscocity. For the other gears, I use marine grease:

    https://www.amainhobbies.com/maxima-...-80916/p548109
    Everyday's a gift, thus now is called the present.

  14. #14
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    I use marine grease for everything including differentials

  15. #15
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    1M in the rear diff has been excellent
    fabricator

  16. #16
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    With the open diff from traxxas or the mod from the video in previous comment above, do you loose the caliper for the brake, the guy mentioned it in the video but wasn't sure if it would be the same for the part from traxxas.

    Thanks for all your help

  17. #17
    RC Champion RCWilly's Avatar
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    Quote Originally Posted by firemedicUSAR View Post
    With the open diff from traxxas or the mod from the video in previous comment above, do you loose the caliper for the brake, the guy mentioned it in the video but wasn't sure if it would be the same for the part from traxxas.

    Thanks for all your help
    No, you actually still get to keep it. The rear differential drops right in and fits without drawbacks. I think the video you were referring to was made before Traxxas came out with the rear diff. Just to clarify, you only need the rear differential and some grease.
    Everyday's a gift, thus now is called the present.

  18. #18
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    RCWilly,

    Thank you that helps! Just wondering I was looking at the traxxas web site and they have aluminum trailing arms, are they any good? Is any of their aluminum stuff good? (Toe links, shock caps ect)

    Thanks again for all your help

  19. #19
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    Traxxas' aluminum parts are prime time.

    There definitely are RC companies whose aluminum is to be mostly avoided, but Traxxas isn't one of them. GPM and Integy have a reputation for being junk, Chinese cast aluminum. Sometimes their stuff is decent but usually their bad reputation is proven true.

    Buy Traxxas with confidence.

  20. #20
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    Fallen,

    I was just reading up on those two, I was also told RPM's plastic doesn't hold up. Do you have any experience with Vitavon?

  21. #21
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    I don't, but several forum members have great things to say about Vitavon. Seems worth the cost.

    RPM's parts are solid, and they do hold up to severe abuse.. The RPM front suspension parts for the UDR have been reported to have clearance issues however, making them a swing and a miss.

    I have RPM'S trailing arms on my UDR and I've been very happy with them.

  22. #22
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    I have rpm trailing arms on mine an d they are doing great.

    I have the vitavon rear axle housing and beadlocks and they are doing great. I had the gpm axle housing but it had tons of problems. Vitavon is well worth the cost and I recommend them. As far as traxxas aluminum parts, I think they are nice but way too expensive. Their aluminum trailing arms are 130$ when I could go buy the rpm ones for 15.

  23. #23
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    Ikemort, Fallen

    That's good to know on the RPM, per your guys recommendation I ordered a spare pair of RPM trailing arms. Currently I'm driving on the street due to the amount of snow we have, I'm waiting on the rear diff to come back in stock.

    On a side note I was watching a video on the Losi SBR 2.0 and it rolled just as easy as the UDR. I don't see anyone talking about that issue.

  24. #24
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    I would also recommend the rpm front bumper and skidplate because the stock one broke within a few runs.

    I have seen the sbr roll a lot too but these trucks are made to be realistic so it doesn’t surprise me that they can roll over easy. You just have to learn how to drive it and not roll over.

  25. #25
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    Ikemort,

    When you say broke within a few runs, where you driving it hard?

  26. #26
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    Well I endoed it pretty hard but most of the damage was the skid plate from hitting the ground when jumping. I’ve also endoed it quite a bit with the RPM bumper and it takes it great.

  27. #27
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    Just out of curiosity I was reading the rear diff install and they use Traxxas grease, how does that stand up to marine grease, Lucus, 1M or other brands.

    https://traxxas.com/news/udr/rear-di...l-installation

  28. #28
    RC Champion RCWilly's Avatar
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    I've only ever used Marine grease and the Traxxas grease, and I can't really tell the difference other than the color.
    Everyday's a gift, thus now is called the present.

  29. #29
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    This Can Save Ya Some Money Doing The Same Thing...


  30. #30
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    Thank you I will look into it!

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