Big Rock Wheels not turning and motor is whining

[Bolshevikjoe]

Well yeah, the whole plastic unit that the motor is attached to. It houses the slipper assy. and pinion/spur gears.
Refer to your manual or Arrmas website for instructions. Seems you never opened it up before, if you have to ask? Get used to removing it. Where most issues arise from within.
Yeah it needs to be opened. Usually this is where you start. And where the problem usually lies, if it is not, then next you look over the front and rear diffs and driveline, with the P.M. still detached. The best way to detect any binding/ diff gear issues.

I cannot describe to you the level of panic I experienced as a complete newb with a new (to me) BigRock that wasn't running right after a heavy front impact (bent the motor mounting plate as it turns out) when, whilst trying to pry the power module use with a screwdriver and just the right amount of profanity, I broke the 'pull here' tabs off of the module and just regretted all of my life decisions leading up to that moment. Ended up using the screwdriver as a chisel and hammering the power module loose. Ended up replacing the motor mount and went ahead and put in an upgraded spur and I'm still running the machine (sans tabs) today.

Moral of the story, watch a couple of youtube videos and bookmark the good ones and then have at it. You're gonna be alright, even if things don't go to plan. You'll get it figured out and if you don't, there's literally thousands of folks out here willing to help point you in the right direction. This whole community is pretty amazing in that respect.

 

[SaltyLocal]

I cannot describe to you the level of panic I experienced as a complete newb with a new (to me) BigRock that wasn't running right after a heavy front impact (bent the motor mounting plate as it turns out) when, whilst trying to pry the power module use with a screwdriver and just the right amount of profanity, I broke the 'pull here' tabs off of the module and just regretted all of my life decisions leading up to that moment. Ended up using the screwdriver as a chisel and hammering the power module loose. Ended up replacing the motor mount and went ahead and put in an upgraded spur and I'm still running the machine (sans tabs) today.

Moral of the story, watch a couple of youtube videos and bookmark the good ones and then have at it. You're gonna be alright, even if things don't go to plan. You'll get it figured out and if you don't, there's literally thousands of folks out here willing to help point you in the right direction. This whole community is pretty amazing in that respect.

Thank you for the support and kind suggestions! Great little forum for a novice.

 

[Diem Turner]

Thank you for the support and kind suggestions! Great little forum for a novice.

This place is amazing. Best forum on the net with no close second. Great to have you aboard

 

[SrC]

It's gets even better when you are invited to the VIP lounge in the penthouse.. (13th Floor) That's when AF gets interesting.

 

[King blitz]

Videos speak louder than words..if we had one of what it's doing and not doing we could probably diagnose this issue quickly..

 

[SaltyLocal]

Hi Team AF,

I’m hoping someone can tell me if things are looking, moving and sounding OK, before I start putting my sons BR front end back together. I put my spare K6s 652 servo in and upgraded to the HR servo saver and bellcrank steering assembly. While I was at it, I filled the front shocks with 55wt fluid (I’ll do the rear prior to driving), and also topped off the diff fluid using 20k diff fluid, I loctite the diff driveshafts, and I’ll give a good red-n-tacky rub down (sounds dirty, not intentional) before reinstalling. I hoping everything looks and sounds ok so I can get it back together for him.

Any input? Thanks you guys/girls!

Videos:
Servo test (which made a very weird, almost draining and struggling sound to stay powered on (not on video as I powered it down cause it sounded off). This vid is after the first power on…

https://www.dropbox.com/s/1uug8suudg5bqqo/Video Nov 30 2022, 7 35 21 PM.mov?dl=0

Servo arm attached to bellcrank test. I recentered the servo prior to attaching to bellcrank. Does it look like it has very little left/right travel or is that the way it suppose to be? I haven’t set the endpoints yet, so maybe that’s why???

https://www.dropbox.com/s/zjlis3z9ufuttxw/Video Nov 30 2022, 7 44 09 PM.mov?dl=0
New diff gasket since I over tightened and tore the prior gasket.

A little fluid easing out. Normal?

 

[King blitz]

Shouldnt leak at all but it seems like you did everything right.id take apart again and re clean that seal lube it first then reinstall it but don't over tighten it.little at a time .wipe and check again repeat till it stops
Sorry I allways jump into a thread that's 4 pages long already with the advice you needed . apologize for saying what others have said .my badd

 

[SaltyLocal]

Shouldnt leak at all but it seems like you did everything right.id take apart again and re clean that seal lube it first then reinstall it but don't over tighten it.little at a time .wipe and check again repeat till it stops
Sorry I allways jump into a thread that's 4 pages long already with the advice you needed . apologize for saying what others have said .my badd

No apology needed bro! I appreciate the feedback. I’ll recheck the gasket tomorrow. I’m just nervous taking it back apart and then carefully reassembling without damaging another gasket.

 

[Senton_Prime]

Did you fill it up full or leave a little room!?

 

[King blitz]

No apology needed bro! I appreciate the feedback. I’ll recheck the gasket tomorrow. I’m just nervous taking it back apart and then carefully reassembling without damaging another gasket.

I hear ya . order more for the future.allways good to have them on hand.i have a big rock also .I love it good luck

 

[SaltyLocal]

Did you fill it up full or leave a little room!?

I left some room. Just barely over the center bearing.

 

[SaltyLocal]

From my posted vids above, does all look good?

 

[Velodromed]

From my posted vids above, does all look good?

Is it possible to post the videos to YouTube and then copy and paste the link? I can’t do the dropbox thing.

 

[SaltyLocal]

Is it possible to post the videos to YouTube and then copy and paste the link? I can’t do the dropbox thing.

Never posted to YT but I think the video uploaded as a short…

“Servo test (which made a very weird, almost draining and struggling sound to stay powered on (not on video as I powered it down cause it sounded off). This vid is after the first power on”…

Servo only:

“Servo arm attached to bellcrank test. I recentered the servo prior to attaching to bellcrank. Does it look like it has very little left/right travel or is that the way it suppose to be? I haven’t set the endpoints yet, so maybe that’s why???”…

Servo and bellcrank movement:

 

[Velodromed]

Never posted to YT but I think the video uploaded as a short…

“Servo test (which made a very weird, almost draining and struggling sound to stay powered on (not on video as I powered it down cause it sounded off). This vid is after the first power on”…

Servo only:

“Servo arm attached to bellcrank test. I recentered the servo prior to attaching to bellcrank. Does it look like it has very little left/right travel or is that the way it suppose to be? I haven’t set the endpoints yet, so maybe that’s why???”…

Servo and bellcrank movement:

Go ahead and set your endpoints and see if there’s any improvement. *But before you do that, make sure your trim knobs are correct. The steering rate knob (all the way on the left) should be at 100%. If it’s not set at 100% now that might be why you’re not getting much from the servo . The steering trim and throttle should be zeroed out.

Then post an update if there’s any changes or improvement. By the way, have you watched videos on this? Google razorRC 3S videos on YT. He has some good ones on setting end points and setting up the servo.

 

[SaltyLocal]

Go ahead and set your endpoints and see if there’s any improvement. *But before you do that, make sure your trim knobs are correct. The steering rate knob (all the way on the left) should be at 100%. If it’s not set at 100% now that might be why you’re not getting much from the servo . The steering trim and throttle should be zeroed out.

Then post an update if there’s any changes or improvement. By the way, have you watched videos on this? Google razorRC 3S videos on YT. He has some good ones on setting end points and setting up the servo.

Yes Sir! I’ve watched and I’m extremely thankful for his vids. I forgot to check the trim knobs. (Novice mistake). When you say zeroed out…do you mean both trim and throttle should be basically turned off all the way to zero?

 

[Diem Turner]

Yes Sir! I’ve watched and I’m extremely thankful for his vids. I forgot to check the trim knobs. (Novice mistake). When you say zeroed out…do you mean both trim and throttle should be basically turned off all the way to zero?

He means to have both the steering and throttle trim set to middle (zero). To the left will be negative values, to the right will be positive (or left and right in the case of steering trim).

 

[Velodromed]

Yes Sir! I’ve watched and I’m extremely thankful for his vids. I forgot to check the trim knobs. (Novice mistake). When you say zeroed out…do you mean both trim and throttle should be basically turned off all the way to zero?

The throttle trim and steering trim should be top dead center. I should’ve explained it a bit better. The steering rate should be all the way to the right at 100%. Trust me, you will make many novice mistakes even when you’re no longer a novice. That’s how we learn best.

 

[SaltyLocal]

.

 

[Velodromed]

Welp, took the rear diff apart to check wtf it was leaking still, and go figure, I once again tore the brand new gasket. Just saying F it and buying a new, already put together, diff.

Im thinking this one’s damaged as I didn’t even over tighten it. In the 3rd photo below, the diff housing looks warped.
View attachment 259928

View attachment 259929

View attachment 259930

I even insured each screw hole in gasket was aligned perfectly! I don’t get it.

Don’t get frustrated, I went through similar issues while learning. It’ll all come together. Go ahead and get a new diff so you can get your car running again. Keep working on that one though, you’ll get it down.