1. Ask questions. Share your HPI Savage knowledge. Register TODAY!

Welcome to HPISavageForum, a friendly forum to discuss the Savage RC Truck.

Your voice is missing! You will need to register to get access to the following site features:
  • Reply to discussions and create your own threads.
  • Our modern chat room. No add-ons or extensions required, just login and start chatting.
  • Access to private conversations with other members.

We hope to see you as a part of our community soon!

BP differential need new alum gearbox? or stock good?

Discussion in 'Chassis & Drivetrain' started by SavageLyfe, Oct 15, 2016.

  1. SavageLyfe

    SavageLyfe Active Member

    Messages:
    82
    Likes Received:
    11
    Joined:
    Oct 15, 2016
    Basically as the title states I'm looking to upgrade my diffs since i just got a lrp 32 and i have stock diffs. They are starting to mess up. I already have upgraded arms, driveshafts and so on just stock diff case and gears. Do i need to get a new case/box for new gears or can i use the plastic one? (Savage X)(built from ground up)
     
  2. Jam Racing 1

    Jam Racing 1 NPTB Monitor, Master of the known universe.... HPISF Staff

    Messages:
    3,765
    Likes Received:
    485
    Joined:
    Jun 20, 2008
    The plastic diff cup can get soft and spread under load. get the alloy diff cups and shim your gears correctly and never look back
     
  3. SavageLyfe

    SavageLyfe Active Member

    Messages:
    82
    Likes Received:
    11
    Joined:
    Oct 15, 2016
    Do you have a link for either of those? would be much appreciated! and so stock plastic gearbox is good?
     
  4. Jam Racing 1

    Jam Racing 1 NPTB Monitor, Master of the known universe.... HPISF Staff

    Messages:
    3,765
    Likes Received:
    485
    Joined:
    Jun 20, 2008
  5. francis Labarbara

    francis Labarbara Well-Known Member

    Messages:
    456
    Likes Received:
    66
    Joined:
    Oct 9, 2015
    Location:
    West Virginia
  6. SavageLyfe

    SavageLyfe Active Member

    Messages:
    82
    Likes Received:
    11
    Joined:
    Oct 15, 2016
    Do you think it slows it down any?
     
  7. Jam Racing 1

    Jam Racing 1 NPTB Monitor, Master of the known universe.... HPISF Staff

    Messages:
    3,765
    Likes Received:
    485
    Joined:
    Jun 20, 2008
    It adds needed strength to the differentials. one of the best additions to any Savage
     
  8. olds97_lss

    olds97_lss Well-Known Member

    Messages:
    907
    Likes Received:
    142
    Joined:
    Oct 2, 2015
    Location:
    Dekalb, IL 60115
    The cup that holds the spider gears to the spur should be alloy. The case the entire diff goes into is fine on the X type diff case halves (gearbox I think it's referred to if you buy it). The older savage 21 style diff case halves (gearbox) were more flexible and tended to not hold a good mesh even when shimmed. The X style cases (that split so you can pull the diff out of the rear/front) are much more solid. Still need to shim properly. That said, I don't think mine needed any shims as the gear lash was fairly tight when I put the BP's in.

    I found out the hard way though on the older savage cases that the newer big extra HD diff outdrives won't fit through the bearing hole. I had to dismantle them and put my old outdrives on. I had alloy diff cases on my old savage as it started as a 21 savage.

    Old 21 savage style diff case, it had a case and a bulkhead:
    [​IMG]

    It's hard to find alloy ones like the new X style case where it's all one piece.
     
    • Like Like x 1
  9. Caretaker109

    Caretaker109 Well-Known Member

    Messages:
    325
    Likes Received:
    61
    Joined:
    Aug 27, 2015
    Location:
    The Netherlands
    The Composite bulkheads are the best option if you stay with plastic.
    Alu diff cups, BP gears and composite bulkheads. Properly shimmed and drive it... :)
     
Verification:
Draft saved Draft deleted

Share This Page