Reverse steering shake / wobble >>

[andrewking00]

Hello,

New Granite Mega steering wobble when reversing. Any ideas what could be the culprit? Is this just the nature of the front end?

Thanks!
Andrew

 

[DesertFury]

How bad is the wobble? Caster could be the culprit since it is not optimized for reverse

 

[andrewking00]

Thanks for the response. It's more of a left/right shimmy. Almost like steering linkage is loose.

 

[ajdragon]

Hi

Check the servo arm to see if is loose, and also the way that Arrma designed and mounted the steering bell crank will also lead to a lot of play in the steering.

 

[andrewking00]

Thanks again for the advice. I just want to know if this is normal, might save me the effort of tearing it down to take a look.

Here's a quick video of the issue:

 

[ajdragon]

Hi

Yup that's normal, but you can take some of that play out by making sure the screws are tightened properly on the cross bar and that the servo arm is nice and tight, and tighten the servo saver about 1/4 to half a turn.

 

[andrewking00]

thanks - will do.

 

[Walter]

Also check out this thread. I posted a link that explains the front wheel wobble when reversing in more detail. It has to do with the caster angle of the front end.

http://arrmaforum.com/threads/reverse-wiggle.63/#post-266

 

[andrewking00]

perfect. thanks for the link.

i did pull apart the front end, nothing seemed out of line or broken. i tightened a few things, but the significant wobble is still present in reverse. guess we'll live with it!

 

[BigSplit]

Walter is spot on. That's what I found out after noticing it when I got my first Granite and researching. I guess it's a bigger issue on 2wd then 4wd rc's.

 

[Drewski]

I have asked my LHS he said most monster trucks with a servo saver will do the same thing.. I call bullshit. I think it's a piss poor design. My granite is 3 times worse than that. I have a tmaxx that's 10 years old and still doesn't slap the steering backing up!

 

[BigSplit]

Google "steering wobbles in reverse", you won't find a 2wd vehicle without new people to the hobby asking on forums why it does it. It's common with every vehicle to some extent

 

[andrewking00]

Yeah. It's pretty sloppy. There's no control whatsoever in reverse unless you are pinned hard left or right.

I know what I should do to fix it. Buy a LiPo battery.

 

[BigSplit]

And a Tmaxx is 4wd isn't it? It's not as noticeabe on 4wd trucks

 

[Drewski]

I'm not talking about the wobble backing up on my tmaxx im talking about the slop in general. There is almost no slop in the steering on the tmaxx. I can guarantee the slop on my granite makes up for a 1/4 of the steering, if not more!!

 

[ajdragon]

Hi

If you take the servo cover off and look at the holes where the steering support pins are held in place, you will notice that one of the holes will look like this "0". That is where most of your play is coming from.

 

[Drewski]

Yes im familiar with the pins your talking about. I've replaced most of those parts trying to tighten it up. I'm with the rest of the guys and have learned to live with it.

 

[paulybatz]

I just bought a V2 used and the guy worked
It and two test runs I noticed the same thing.
Hard reverse after about 20 - 30 feet gets the wheels slapping left right. Any fix? Total noob here, coming into this a little blind. A little upset, please advise. Thank you in advance.

 

[2fast4u]

I just bought a V2 used and the guy worked
It and two test runs I noticed the same thing.
Hard reverse after about 20 - 30 feet gets the wheels slapping left right. Any fix? Total noob here, coming into this a little blind. A little upset, please advise. Thank you in advance.

As per Walter's post above (#8) it is due to caster angle. And exaggerated by any play in the steering. When moving forward the caster angle is positive, in reverse the angle has not changed any but becomes effectively negative creating instability. Any play in the steering makes it worse.

 

[bicketybam]

I rarely use reverse, usually to back away far enough to turn around.