Register and gain access to Discussions, Reviews, Tech Tips, How to Articles, and much more - on the largest Arrma RC community for RC enthusiasts that covers all aspects of the Arrma-RC brand!

Register Today It's free! This box will disappear once registered!

How to shim your Arrma diff

Discussion in 'Chassis & Drivetrain' started by WoodiE, Dec 19, 2017.

  1. WoodiE

    WoodiE Kind of good admin
    Staff Member

    Joined:
    May 14, 2015
    Messages:
    2,896
    Likes Received:
    1,897
    Location:
    Lexington, KY
    This is something we get asked a lot on the forums and nearly every single time the answer to those threads are to watch this video. So as suggested, I created a sticky thread for this very question.

    We can also use this thread to have a "one place to go" for this information.

    Also check out the thread: Shims that work for Arrma diffs



    Enjoy!
     
    Trapper and Jerry-rigged like this.
  2. deadair

    deadair Active Member

    Joined:
    Dec 12, 2017
    Messages:
    14
    Likes Received:
    5
    Arrma RC's:
    Granite
    I know I posted this in another thread but after reading different threads/youtube vids, I think this would be a good place for everyone to see this question and answer.

    Do you treat all 3 diffs the same?
     
  3. Jerry-rigged

    Jerry-rigged Premium Member!
    Premium Member Excellence Award

    Joined:
    Apr 27, 2016
    Messages:
    1,794
    Likes Received:
    979
    Location:
    Texas, Baby!
    Arrma RC's:
    Kraton, Typhon, 4x4-Mega
    For the 6S machines -
     
    Swift518 likes this.
  4. Jerry-rigged

    Jerry-rigged Premium Member!
    Premium Member Excellence Award

    Joined:
    Apr 27, 2016
    Messages:
    1,794
    Likes Received:
    979
    Location:
    Texas, Baby!
    Arrma RC's:
    Kraton, Typhon, 4x4-Mega
    Links to shims -
    For the internal shims -
    Mugen Seiki Differential Washer Set X6/X6T/M-Spec
    https://www.towerhobbies.com/cgi-bin/wti0001p?&I=LXJAM6
    that Mugen set is often sold out.

    For the external shims -
    Tekno RC Differential Shim 13x16x.1 EB48 (10)
    https://www.towerhobbies.com/cgi-bin/wti0001p?&W=003058064&I=LXDWDG&P=K

    Some Protec 3.5x12 x 0.2mm shims -
    https://www.amainhobbies.com/protek-rc-3.6x12x0.2mm-differential-gear-washer-10-ptk-h-5914/p188802

    and the Arrma shim set -
    https://www.amainhobbies.com/arrma-washer-5x18x0.3mm-6-ara709024/p409556

    Note, that if you buy a diff internal gear set, it comes with the small 3.5x12 shims -
    https://www.amainhobbies.com/arrma-differential-gear-set-ara310436/p409428
     
    #4 Jerry-rigged, Jan 10, 2018
    Last edited: Jan 11, 2018
    Iamtheoutcast and Lbizzle like this.
  5. Jerry-rigged

    Jerry-rigged Premium Member!
    Premium Member Excellence Award

    Joined:
    Apr 27, 2016
    Messages:
    1,794
    Likes Received:
    979
    Location:
    Texas, Baby!
    Arrma RC's:
    Kraton, Typhon, 4x4-Mega
    Lbizzle likes this.
  6. crankestein

    crankestein Well-Known Member

    Joined:
    Mar 18, 2017
    Messages:
    253
    Likes Received:
    104
    Location:
    Area 54
    Arrma RC's:
    Talion
    For those shim days... lol!

     
  7. Raji

    Raji Well-Known Member

    Joined:
    Oct 22, 2017
    Messages:
    268
    Likes Received:
    124
    Arrma RC's:
    Outcast
  8. Jerry-rigged

    Jerry-rigged Premium Member!
    Premium Member Excellence Award

    Joined:
    Apr 27, 2016
    Messages:
    1,794
    Likes Received:
    979
    Location:
    Texas, Baby!
    Arrma RC's:
    Kraton, Typhon, 4x4-Mega
    Brand does not matter, I don't think. Just watch the size and thickness.
     
    Raji likes this.
  9. Motorider

    Motorider Well-Known Member

    Joined:
    Feb 5, 2018
    Messages:
    81
    Likes Received:
    11
    Arrma RC's:
    Kraton
    Hello everyone. First post here. Took an Arma Kraton v2 in trade for a stock rtr bomber. Tore down the diffs for inspection and found a nightmare. The ring and pinion gears are all toast. The gear mesh on the motor was wicked tight. Zero play. The diffs were all missing factory shims and filled with plain old marine lithium grease. I can't imagine this thing worked well for him.

    Anyhow in my search for parts I have become very dissappointed. Either these things fail a lot and parts are in high demand, or there are supply chain problems. Either way it sucks. What I ended up doing was buying 2 complete diff sets off of flea bay for $68 shipped. Hell the ring gears are $20 alone. I was; however, very pleased with the ease of access. Thanks Arma.

    The big question is what version of diffs did I buy and will they come with the 5x18x.2mm shims installed. I really want to get this car going this week.


    Your shims listed don't all work out. The arma part number ara709024 is for the 3.5x12x.15mm shims.

    I'm in dire need of the 5x18x.2mm shims. Any arma part numbers?

    Also, what oils are working well for everyone in the diffs?

    Thanks for any and all guidance.
     
  10. Jerry-rigged

    Jerry-rigged Premium Member!
    Premium Member Excellence Award

    Joined:
    Apr 27, 2016
    Messages:
    1,794
    Likes Received:
    979
    Location:
    Texas, Baby!
    Arrma RC's:
    Kraton, Typhon, 4x4-Mega
    yeah, you can say that... Hobbico only supplies probably 1/2 to 3/4 of all the hobby shops, and owns Arrma. Supply chain problems are an understament...

    The diffs do not have the 18x5 shims from the factory, only the smaller 12x3.5 shims... And yeah, those 18x5 are hard to find. Seems I have heard of some people using either the Tekno 15x5 shims (for the EB410) or the 18x6 (for the SCT410). Also the Mugen shims for the "high traction diffs" and the AE B8.3 diff shims supposedly work, although I don't know the exact size of those shims.
     
  11. Motorider

    Motorider Well-Known Member

    Joined:
    Feb 5, 2018
    Messages:
    81
    Likes Received:
    11
    Arrma RC's:
    Kraton
    I thought the 5x18mm shim went behind the sun gears inside the diff. The guy in the video for the bulletproof diff on armas website installed it. Called for part number td310475. That is a 5x18x.2mm shim. I could care less what stock came with. I want this thing to last. If it goes like my yeti xl did, I'll sell this thing and get the tekno mt410 I really wanted.

    Anyhow, so what's the preferred diff fluids?
     
  12. Jerry-rigged

    Jerry-rigged Premium Member!
    Premium Member Excellence Award

    Joined:
    Apr 27, 2016
    Messages:
    1,794
    Likes Received:
    979
    Location:
    Texas, Baby!
    Arrma RC's:
    Kraton, Typhon, 4x4-Mega
    exactly, you need to put that 18x5 shim behind the sun gear. The Planetary gears come with shims from the factory, I believe - the smaller 12x3.5. You want all 6 shims (2x sun shims, 4s planetary shims) - then check for binding / slop, and adjust with more / fewer shims from there. Also, don't forget the 16x13 shim for the external bearing - this one will protect the ring and pinion.
     
  13. Motorider

    Motorider Well-Known Member

    Joined:
    Feb 5, 2018
    Messages:
    81
    Likes Received:
    11
    Arrma RC's:
    Kraton

    Thanks. Good explanation. I noticed a good amount of slop on both outdrives. I assume that the sun gear shims will take that up. Can't wait to get this thing online.
     
  14. Raji

    Raji Well-Known Member

    Joined:
    Oct 22, 2017
    Messages:
    268
    Likes Received:
    124
    Arrma RC's:
    Outcast
  15. Mongoose

    Mongoose Well-Known Member

    Joined:
    Jan 31, 2018
    Messages:
    354
    Likes Received:
    91
    Arrma RC's:
    Kraton, 4x4-Mega
     
  16. Jerry-rigged

    Jerry-rigged Premium Member!
    Premium Member Excellence Award

    Joined:
    Apr 27, 2016
    Messages:
    1,794
    Likes Received:
    979
    Location:
    Texas, Baby!
    Arrma RC's:
    Kraton, Typhon, 4x4-Mega
    No, you want to start with one shim behind all 6 gears. Use the stock shims or the extra shims, but not both. 6 gears, 6 shims, then reassemble, and check for binding / slop, and add or remove shims as needed.
     
  17. Mongoose

    Mongoose Well-Known Member

    Joined:
    Jan 31, 2018
    Messages:
    354
    Likes Received:
    91
    Arrma RC's:
    Kraton, 4x4-Mega
    Ok, thanks for the clarification. It makes sense now.
     
  18. asphaltlou

    asphaltlou Well-Known Member

    Joined:
    Feb 4, 2018
    Messages:
    44
    Likes Received:
    20
    Location:
    NE Ohio
    Arrma RC's:
    Typhon, Voltage
    Hmmm I just shimmed my center diff and now its not smooth
     
  19. Jerry-rigged

    Jerry-rigged Premium Member!
    Premium Member Excellence Award

    Joined:
    Apr 27, 2016
    Messages:
    1,794
    Likes Received:
    979
    Location:
    Texas, Baby!
    Arrma RC's:
    Kraton, Typhon, 4x4-Mega
    too many shims...
     
  20. RCROD

    RCROD Well-Known Member

    Joined:
    Dec 23, 2017
    Messages:
    532
    Likes Received:
    176
    Location:
    Vancouver Island, B.C..
    Arrma RC's:
    Kraton, Talion
    As advised here of the forum, I'm now shimming my diffs & started with my front diff on my V3 Kraton. I've built diffs before, but not Arrma diffs. I have the diff all clean and also fully understand how to shim them, so no problems there. However, I cannot remove the internal sun gear on the diff cup side. The other side (which has the large external crown gear) was easy to remove the sun gear. However, the sun gear is quite deep down in the diff cup side, and hard to get at, so very difficult to pull it off the pin/outdrive compared to the other side. I've even tried using needle nose vise grips (which should work), so not sure why I cannot remove the sun gear on the diff case side? I want to add a new bearing on this side, plus remove the o ring to lube with some green slime & most importantly, I need to add a 5x18 shim on the diff cup side. Also, what is the small set screw for on the side of the diff cup, as not one video addresses this? Very frustrating to already have problem on my 1st diff...

    PLEASE HELP ???
     
    #20 RCROD, Mar 15, 2018
    Last edited: Mar 15, 2018
  • Welcome to Arrma Forum

    Arrma Forum is a Arrma RC fan site that was started to give Arrma RC enthusiasts a place to come together and discuss and share their experiences with the entire Arrma-RC product line, such as the Arrma Kraton, Arrma Talion, and Arrma Granite.

    We welcome all Arrma RC enthusiasts, both new and old, racers and bashers that share a common goal - a willingness to help and learn.
  • Disclaimer