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  1. #1
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    RPM Rear Bearing Carriers - Toe in?

    Does anyone know if the RPM rear bearing carriers toe in at all. Truck is handling like crap on indoor dirt/clay. Might need to install a drift gyro!

  2. #2
    RC Champion zedorda's Avatar
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    If you install the on the correct sides they have stock toe in. If installed on the opposite sides I think it reduces the toe in to 1 degree.

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    Do you know which is the correct way? I’ve only noticed on mine the logo faces forward. Thanks!

  4. #4
    RC Champion Mr Wolf's Avatar
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    Quote Originally Posted by zedorda View Post
    If you install the on the correct sides they have stock toe in. If installed on the opposite sides I think it reduces the toe in to 1 degree.
    This is incorrect. I have several sets of the RPM carriers (#80382) and they have zero toe in and have identical geometry to the stock Traxxas ones. You might be thinking of the optional (Traxxas made) Slash 4x4 rear carriers which have 1.5 toe-in and can be forward mounted to increase stock toe-in from 2.5 to 4.0 or reverse mounted to reduce it to 1.0.

    @monkeyracing, the Slash 2WD's stock toe-in 2.5 and comes from its arms. This amount is normally considered plenty for most off-road surfaces so is unlikely to be the source of your bad handling. If you post your set-up, you might be able to get some ideas for useful mods or adjustments. If your surface is very loose, a sealed diff could be bring you some benefits. I run the FLM one on my race Slash and Rustler.
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  5. #5
    RC Champion Mr Wolf's Avatar
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    Quote Originally Posted by zedorda View Post
    If you install the on the correct sides they have stock toe in. If installed on the opposite sides I think it reduces the toe in to 1 degree.
    This is incorrect. I have several sets of the RPM carriers (#80382) and they have zero toe in and have identical geometry to the stock Traxxas ones. You might be thinking of the optional (Traxxas made) Slash 4x4 rear carriers which have 1.5 toe-in and can be forward mounted to increase stock toe-in from 2.5 to 4.0 or reverse mounted to reduce it to 1.0.

    @monkeyracing, the Slash 2WD's stock toe-in 2.5 and comes from its arms. This amount is normally considered plenty for most off-road surfaces so is unlikely to be the source of your bad handling. If you post your set-up, you might be able to get some ideas for useful mods or adjustments. If your surface is very loose, a sealed diff could be bring you some benefits. I run the FLM one on my race Slash and Rustler.
    Pretty please, with sugar on top, clean the RC car

  6. #6
    RC Champion zedorda's Avatar
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    Quote Originally Posted by Mr Wolf View Post
    This is incorrect. I have several sets of the RPM carriers (#80382) and they have zero toe in and have identical geometry to the stock Traxxas ones. You might be thinking of the optional (Traxxas made) Slash 4x4 rear carriers which have 1.5 toe-in and can be forward mounted to increase stock toe-in from 2.5 to 4.0 or reverse mounted to reduce it to 1.0.

    @monkeyracing, the Slash 2WD's stock toe-in 2.5 and comes from its arms. This amount is normally considered plenty for most off-road surfaces so is unlikely to be the source of your bad handling. If you post your set-up, you might be able to get some ideas for useful mods or adjustments. If your surface is very loose, a sealed diff could be bring you some benefits. I run the FLM one on my race Slash and Rustler.
    You are right it was the 4x4 I was thinking about. But I think you are wrong about the a-arms having the toe on them. About 2 months back I installed the RPM trans case on my Slash 2wd with the multiple mount points for the a-arms to change the toe settings so I could take most of the toe out. The a-arms are identical but the stock trans case has toe in on it. I completely forgot I found I had to do that way to change the rear toe. I think there is another way by using the 4x4 rear carriers but figured I would only confuse myself by have 2 points where toe was being changes and didn't the extra math. So I went the RPM trans route to make it simpler. I didn't remember any of this till I pulled out my Slash 2wd and looked at it without the stock trans case.

    Sorry old age memory is letting me down.

  7. #7
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    Not to go into a complete setup, but at the rear I’m using all RPM parts, from the diff to the carriers. I’ve got the 0 blocks installed on the trans. I need to measure things a little more closely, but just by eyeballing, it appears I have about 1.5 toe in on the right side and 0 on the left.

    I’m going to tear into it to look for bent parts and to install the toe-in blocks. I need to replace the carriers and bearings anyway.

  8. #8
    RC Champion Mr Wolf's Avatar
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    Quote Originally Posted by zedorda View Post
    But I think you are wrong about the a-arms having the toe on them.
    You think wrong I'm afraid, although they actually have 3 of toe-in (not 2.5 as I said previously - that's the Slash 4x4), exactly the same toe-in as the Protrac kit's rear arms. The stock 2WD Magnum 272 gearbox has zero toe-in on the arm mounts which why Rustler/Pede 2WD owners love those Protrac arms so much.

    The Slash 4x4's 2.5 of rear toe-in is built into the rear bulkhead's arm mounts. It uses straight (i.e. zero toe) arms which are exactly the same arms as Rustler/Stampede 2WDs - part #3655X.
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  9. #9
    RC Turnbuckle Jr. Greatscott's Avatar
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    Do not recommend RPM carriers, they flex too much causing all kinds of problems. Recommend going aluminum here.
    Submarine Qualified, Chief Inducted, Navy Retired

  10. #10
    RC Champion zedorda's Avatar
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    Quote Originally Posted by Mr Wolf View Post
    You think wrong I'm afraid, although they actually have 3 of toe-in (not 2.5 as I said previously - that's the Slash 4x4), exactly the same toe-in as the Protrac kit's rear arms. The stock 2WD Magnum 272 gearbox has zero toe-in on the arm mounts which why Rustler/Pede 2WD owners love those Protrac arms so much.

    The Slash 4x4's 2.5 of rear toe-in is built into the rear bulkhead's arm mounts. It uses straight (i.e. zero toe) arms which are exactly the same arms as Rustler/Stampede 2WDs - part #3655X.
    So all you would have to do to remove the toe in from a Slash 2wd is swap out the rear a-arms to Slash 4x4 a-arms?

  11. #11
    RC Champion Mr Wolf's Avatar
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    Quote Originally Posted by zedorda View Post
    So all you would have to do to remove the toe in from a Slash 2wd is swap out the rear a-arms to Slash 4x4 a-arms?
    Yes, that would do it but you would then have a track width problem due to the 4x4 arms being about 10mm longer than the 2WD ones. The only way to equalise it would be to use rims with about 10mm more negative offset like Protrac or AE SC10 ones.
    Pretty please, with sugar on top, clean the RC car

  12. #12
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    I tried to install 4x4 rpm arms on my rpm diff case an I realize that my mip x duty driveshaft is short.


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  13. #13
    RC Champion zedorda's Avatar
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    Quote Originally Posted by Mr Wolf View Post
    Yes, that would do it but you would then have a track width problem due to the 4x4 arms being about 10mm longer than the 2WD ones. The only way to equalise it would be to use rims with about 10mm more negative offset like Protrac or AE SC10 ones.
    So the OP could just use 4x4 rear hubs to get more toe in on his Slash 2wd?

  14. #14
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    Well, one way to find out for sure is to bust out the caliper and do some measuring.

  15. #15
    RC Champion Mr Wolf's Avatar
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    The stock rear 4x4 hubs (#1952) have zero toe-in. The optional 4x4 ones have 1.5 so in theory these could be used to increase it to 4.5 but IMO that's too much. Another problem with this, although it should fit into the arm OK, the #1952 hub is appreciably larger than the stock 2WD one (#3752) and this will naturally impact the level of camber gain at the wheel when the suspension is compressed.
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  16. #16
    RC Champion zedorda's Avatar
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    Quote Originally Posted by Mr Wolf View Post
    The stock rear 4x4 hubs (#1952) have zero toe-in. The optional 4x4 ones have 1.5 so in theory these could be used to increase it to 4.5 but IMO that's too much. Another problem with this, although it should fit into the arm OK, the #1952 hub is appreciably larger than the stock 2WD one (#3752) and this will naturally impact the level of camber gain at the wheel when the suspension is compressed.
    Thank you very much for all the details I will bookmark this thread. Because I couldn't find this information when I was trying to reduce the toe in on my Slash 2wd and found it confusing as heck trying to get the details from older posts. Since the 2wd and the 4x4 deal with toe two different ways I got them mixed up easily.

    Do you have the part number for the optional 4x4 rear carriers with the 1.5 degrees of toe? I want a set of them.
    Last edited by zedorda; 10-21-2019 at 12:54 PM. Reason: cleaned up ****

  17. #17
    RC Champion Mr Wolf's Avatar
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    Quote Originally Posted by zedorda View Post
    Do you have the part number for the optional 4x4 rear carriers with the 1.5 degrees of toe? I want a set of them.
    1952X - Aluminium only I'm afraid so you'll need to get your wallet out.

    The Traxxas 4-Tec rear carriers (#4352) might be a better option for you. I remember the Jang over at URC using them on his “ultimate Rustler” project many moons ago.

    https://www.rcplanet.com/traxxas-rea...4-tec-tra4352/
    Last edited by Mr Wolf; 10-21-2019 at 01:43 PM.
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  18. #18
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    The RPM rear arms measured out to be 1mm to 1.5mm longer on the trailing edge. This would give them some inherent toe in.

    I measured from outside edge to outside edge and verified by checking the insides of the hinge pin holes. The latter method did introduce a minor error, due to measurement angles not being parallel.

    Anyway, I still want a little more toe in, so I’ll try the 3 blocks.

  19. #19
    RC Champion zedorda's Avatar
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    Quote Originally Posted by monkeyracing View Post
    The RPM rear arms measured out to be 1mm to 1.5mm longer on the trailing edge. This would give them some inherent toe in.

    I measured from outside edge to outside edge and verified by checking the insides of the hinge pin holes. The latter method did introduce a minor error, due to measurement angles not being parallel.

    Anyway, I still want a little more toe in, so I’ll try the 3 blocks.
    Guessing you don't have the other mounting tabs for the RPM trans case? Because you should be able to use them to get the toe in you are wanting also.

  20. #20
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    Yup. I’ve got them. Just verifying where the standard toe in comes from.

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