Granite Granite gear issues?

[tuggy]

Hi all. I had my Granite out today. It was running on icy grass. It then suddenly stopped and I couldn’t drive forwards or backwards. I took it home and though it was the slipper needing tightened. I removed the drive shaft but it wouldnt tighten when I had either the plastic spanner that comes with the car, or an Allen key in it. I have tried forwards and backwards whilst everything is open but its now only making a grinding noise and is barely turning the cog where the driveshaft would normally be. Any ideas?
I can’t seem to upload a video

 

[RCBro80]

Can you upload a video to youtube and post it here?

 

[tuggy]

 

[RCBro80]

Hmm... have you checked the mesh between the pinion and spur? It possibly looks like they're barely in contact

 

[tuggy]

How do I get into that? I was struggling to see how to open all that up?

 

[RCBro80]

 

[RackwitzG]

How do I get into that? I was struggling to see how to open all that up?

I agree that the gears arn't touching. Take the power module out. The manual tells you how. If you don't have one, go to ARRMA Website. There are youtube videos on the topic as well. razorrc has a video about how to set the gear mesh correctly.

 

[tuggy]

Hi, I’ve got the pinion exposed and it’s operating freely backwards and forwards

 

[Edough13]

Either your motor mount screws come loose causing your motor to slide over, or your slipper is way loose. Pull the power module apart and check if your motor is moving in the mount. If not pull the slipper out and tighten it all the way tight and then loosen 1 1/2 turns

 

[4x4Bash]

Hi, I’ve got the pinion exposed and it’s operating freely backwards and forwards

The pinion is supposed to be up against the spur gear. Look up youtube videos on setting the pinion mesh and things should make sense to you.

 

[tuggy]

Hi again guys. I’ve been 3 hours trying to sort this today. I took out the gears and on the other side from where it meets the pinion - the 2 kinda hexagonal plastic like cogs were really loose and all over the place. I assumed I had to place them into the shape they fitted and tighten up, which I did. I put it back together again and adjusted the pinion so it was running smoothly. I put the driveshaft back in and ran it for 2 seconds and it’s gone again :-(

 

[4x4Bash]

Did the pinion move away from the spur gear again? The screws holding the motor in could he loose again.

Can you take a picture of your motor mounted in, spur gear assembly there but one side of the casing removed? Might help troubleshoot.

 

[tuggy]

I’ve come back into the house as it is freezing in the garage, so no photos just now. Im needing to take a step away from it too. I think I am going to need to strip down the spur gear after looking at YouTube videos. The pinion never seemed to move. I made sure the two screws for the motor were tightened up too. The motor moves fine and quietly when not connected. I did notice that the gear was slightly chewed after i ran it once re-built, which it wasn’t before

 

[RCBro80]

If the pinion isn't spinning when the motor turns, then the pinion grub screw is probably loose. However, if you gears chewed up, you'll probably want to replace those while you're in there.

 

[tuggy]

The pinion is spinning when the motor turns. It sounds and runs good when it’s just the pinion. However when I connect up the gears that’s when I’m getting issues

 

[RCBro80]

Gotcha.

With the motor module removed, are you able to roll the vehicle forward and backward smoothly? If not, you could have a damaged input gear or ring gear on the rear differential.

 

[tuggy]

Thanks. I’ll get a look at that tomorrow. I’m a newbie to this and the learning curve is massive. I really appreciate all your help.
So, when the motor is removed and if the car is rolling fine, do you think it’ll be the gears?

Also, something random I noticed. When I moved the wheels with the car lifted off the ground - the lhs one seems to go forward and the rhs one seems to go backwards. I can’t remember if that was on the front or rear wheels

 

[RCBro80]

Your observation about the wheels moving in opposite directions is normal - this is what the differentials do. This is one of my favorite vintage videos that pops up on my IG every so often, explaining exactly how this works in a car:

 

[tuggy]

All makes sense when you see it like that eh!

OK - I’ve got a fresh perspective and a clear head to go at it again tomorrow. I’ll strip down the spur gear and reassemble. I’ll check the pinion and how it sits with the spur gear. I’ll also check if the car rolls free with the motor removed and then take it from there

 

[GraniteFox]

Little bit of medium thread lock on that grub screw for the pinion. Wont back out later.