Granite Granite BLX 3S Stripped Pinion and Spur Gear

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I have a Granite 4x4 BLX 3S that's a couple of months old. Yesterday it started making a grinding noise and started losing power during hard acceleration. It seems like the pinion and spur gear are stripped. The housing/back plate also seems to be grounded down. I am fairly new to RC and am at a loss of what may have caused this. Any ideas?
 

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Hi and welcome on the forum.

The motor pinion and spur gear's mesh is always too tight on the 3s BLX. I have widen the preset motor position hole to gain more space between the gears. I did it by hand with a 3mm drill bit, the aluminum is pretty soft, it is easy to do. I have also changed the spur for a metal one. And as i have the V1 (BRCC), i must had to change all the slipper also.
 
The bearing looks wasted, look inside the motor cover and dig it out and I bet you will find it seized or tons of play in it causing a wobble
 
The bearing looks wasted, look inside the motor cover and dig it out and I bet you will find it seized or tons of play in it causing a wobble
I had a similar problem with my Granite recently. also a couple of months old. A motor bearing went bad and caused the wobble suchtragedy mentioned. I had the metal spur gear, so that was fine, but my pinion gear was destroyed. The fix was a new motor, new pinion. Open up the motor, check the bearings. There's a chance you'll be able to just replace the bearings. I couldn't the bad bearing was hopelessly stuck. I'm in the process of seeing if the motor and pinion will be covered under warranty.

*EDIT - Horizon Hobby is providing a new motor and pinion under warranty
 
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Thanks so much for all your help! I'm in the process of seeing if these would be covered under warranty as well. Meanwhile, I was able to remove the bearings in the motor. The one in the front seems to have seized up so will get that replaced. The one in the rear is still buttery smooth. I might get an adjustable mount, new slipper and spur gear and fix it up as I'm waiting for warranty.
 
So many 3s cars have this bearing problem. It's because dirt builds up in the power module. Dirt blows bearings, and there's a lot of it when the spur rubs on the plastic housing, and if your mesh was tight too your bearing had no chance ⚰️

When you rebuild it, definitely use the o-ring mod in this thread. Shim the spur so there's no slop and won't rub on the housing. Cut or drill holes in the chassis where the spur sits so any dirt that does build up can sift out, and go for the adjustable motor mount so you can set a better mesh

P.s. your pinion could do with replacing too! When the teeth look like shark fins it's usually because the mesh it too tight
 
Stock bearings must be changed after maybe a few weeks they don't last long remplace them for nice bearings from jimsbearings if you are in the states they are superior to my eyes to fast eddy
 
Stock bearings must be changed after maybe a few weeks they don't last long remplace them for nice bearings from jimsbearings if you are in the states they are superior to my eyes to fast eddy
I already purchased a new motor while waiting to process the warranty claim. How did you get the stock bearings out? I saw the bread trick for the bearing in the removable cap. But how do you get the other out? Camaroboy suggested heating it up, but l still couldn't get it out. I may have not heated it up enough. Any other suggestions?
 
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How did you get the stock bearings out? I already purchased a new motor while waiting to process the warranty claim. Camaroboy suggested heating it up. I still couldn't get the back bearing out. I may have not heated it up enough. Any other suggestions?
Search the "bread trick" in YT. You'll be surprised!
 
I already purchased a new motor while waiting to process the warranty claim. How did you get the stock bearings out? I saw the bread trick for the bearing in the removable cap. But how do you get the other out? Camaroboy suggested heating it up, but l still couldn't get it out. I may have not heated it up enough. Any other suggestions?


More heat in a circular motion around the bore and tappy tap tap.. you can also use a set of long neck snap ring pliers, grind the ends so they have outward facing points.. again heat the can, and pull the outer race with the modified snap ring pliers..
Thanks, yes I found that. But it only works for the bearing in the removable cap right? How about the other one?
EDIT: Actually, just cover up the hole and use the same trick for the back one? Getting the bread out of there is going to be a problem though. Is this how everyone is doing it?


Hydraulic the bearing out with bread or grease only works on blind holes, so if you can make it a blind hole by capping the end of the can with a plate you could continue on to try to find something that will fit the inner diameter of the outer race.. the fit must be good or your wasting your time, poor fit will let the bread/ grease pass by the dowel..
 
Hydraulic the bearing out with bread or grease only works on blind holes, so if you can make it a blind hole by capping the end of the can with a plate you could continue on to try to find something that will fit the inner diameter of the outer race.. the fit must be good or your wasting your time, poor fit will let the bread/ grease pass by the dowel..
EDIT: I thought I found a something for that old motor with the busted bearing, but it's not a good fit. So for the new motor, use the heat trick? I'm kindof nervous about damaging my new motor.

Does the bread trick work on that back bearing on new motors? I see lots of people changing out their motor bearings. How is everyone getting that back one out?
 
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I'm going to try the heat again on that old motor you gave me the original tip on, still has just the outer race stuck. (I'm a little nervous about damaging my new motor.) If it doesn't work, the smaller motor bearings look like they are a tight fit on the inner diameter of the outer race. I think I may be able to try the bread trick with them.


If replacing the bearings in the new motor just push the old one out of the can.. no need for fancy tricks or heat, just rest a tool on the inner race and give it a smack.. obviously discard that bearing if you do so, as it will no longer be any good.. ?
 
If replacing the bearings in the new motor just push the old one out of the can.. no need for fancy tricks or heat, just rest a tool on the inner race and give it a smack.. obviously discard that bearing if you do so, as it will no longer be any good.. ?
Tried it with a small screwdriver, couldn't manage to get a good "grip" on that inner race. Again, I got nervous about damaging the new motor so I stopped. Thanks, I'll try again.
 
Tried it with a small screwdriver, couldn't manage to get a good "grip" on that inner race. Again, I got nervous about damaging the new motor. Thanks, I'll try again.


if you use a screwdriver, and your not careful, your actually wedging it in tighter by only tapping one side.. so you get a pendulum effect from one side to the other, it will eventually walk out like that if going from side to side a little at a time...

but a round tool through the face of the can that fits the whole diameter of the inner race is ideal.. one sharp whack and it will fall right out..

Also always keep in mind a bearing that comes apart, is a bearing that has not been monitored or cared for... it's very good practice to inspect the rigs often (5-6 packs).. it can save a lot of grief in the end game.. ? good luck man, you can do it..✌
 
if you use a screwdriver, and your not careful, your actually wedging it in tighter by only tapping one side.. so you get a pendulum effect from one side to the other, it will eventually walk out like that if going from side to side a little at a time...

but a round tool through the face of the can that fits the whole diameter of the inner race is ideal.. one sharp whack and it will fall right out..

Also always keep in mind a bearing that comes apart, is a bearing that has not been monitored or cared for... it's very good practice to inspect the rigs often (5-6 packs).. it can save a lot of grief in the end game.. ? good luck man, you can do it..✌
Thanks, got it out! Really fortunate I tried again. I must have not tightened my pinion enough, because it came loose, chewed up the slipper case a bit and there was lots of black filth. Only one or two runs put in so minimal damage, but I was looking at another dirty, seized bearing and another motor in no time. Now I need to go buy some bread. :D
 
Ugh, new high priced bearing stuck halfway in and trashed.

EDIT: I did get it out. I have a bearing popper which worked perfectly with the new motor and bearing. I didn't use it before because it didn't work on my old motor with crapped out and stuck in bearing. Ordered another bearing. I'm going to try one more time ...

P.S. Bread trick works.
 
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