Pinion mods

[Spunkybob]

Hi all.
So I completed my kit last week and it has been going fine on 3s with 3 bearings in the rear with no shims (yes bad.. none came in kit but they will arrive tomorrow) and normal as per instruction 2 bearing and spacer in the front.

Now I just upgraded my front bulkhead to the GPM and testing with the stock spacer and 2 hearings it binds up shockingly (as we know) to the point where I can't turn it by hand.

So from my understanding the below diagram is how the 3 installs work.

Stock:
So this works with bearing spacer bearing and 2 shims for 6s (according to manual)

BHB:
Grind down the tabs, use 3 bearings and X number of spacers to pack between the first bearing (held by 3 screws) and the C clip. This brings the pinion away from the spur by a few .** of a mm creating a better mesh.

Standard 3 bearing mod:
Install bearing, about .6mm of shims then 2 more bearings. This leaves a gab between the first bearing and the 3 holding screws so the pinion is a little further away from the spur.

Now... While I understand how the 2 mods work, what is stopping the "3 bearing mod" from sliding forward slightly causing a huge bind?

I am not trying to debate what works/doesn't work I just want to only 1 mod and not spend the $80 (that's how much the gears cost in Australia) if something fails.

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[wdiabc]

when torque is applied to the driveline, there will be a force repelling the pinion and bevel gear away from each other. In your picture, the pinion will try to slide downward, and never upward, when you are either braking or accelerating.

I kept using 3 bearings in my XL and it holds well. But I used castle ESC and tuned the torque down. In my opinion, 6S with a monster ESC plus castle 1515 will destroy any bevel/pinion gear if you are not careful with the throttle.

 

[Spunkybob]

when torque is applied to the driveline, there will be a force repelling the pinion and bevel gear away from each other. In your picture, the pinion will try to slide downward, and never upward, when you are either braking or accelerating.

I kept using 3 bearings in my XL and it holds well. But I used castle ESC and tuned the torque down. In my opinion, 6S with a monster ESC plus castle 1515 will destroy any bevel/pinion gear if you are not careful with the throttle.

Yes this is what I was thinking.. but if your jumping and land nose first won't the pinion slide forward too far? I suppose not because even if it does move a little it can never move further then what was designed by axial while not perfect won't implode.

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[BarHarborBasher]

Hi all.
So I completed my kit last week and it has been going fine on 3s with 3 bearings in the rear with no shims (yes bad.. none came in kit but they will arrive tomorrow) and normal as per instruction 2 bearing and spacer in the front.

Now I just upgraded my front bulkhead to the GPM and testing with the stock spacer and 2 hearings it binds up shockingly (as we know) to the point where I can't turn it by hand.

So from my understanding the below diagram is how the 3 installs work.

Stock:
So this works with bearing spacer bearing and 2 shims for 6s (according to manual)

BHB:
Grind down the tabs, use 3 bearings and X number of spacers to pack between the first bearing (held by 3 screws) and the C clip. This brings the pinion away from the spur by a few .** of a mm creating a better mesh.

Standard 3 bearing mod:
Install bearing, about .6mm of shims then 2 more bearings. This leaves a gab between the first bearing and the 3 holding screws so the pinion is a little further away from the spur.

Now... While I understand how the 2 mods work, what is stopping the "3 bearing mod" from sliding forward slightly causing a huge bind?

I am not trying to debate what works/doesn't work I just want to only 1 mod and not spend the $80 (that's how much the gears cost in Australia) if something fails.

Sent from my SM-G935F using Tapatalk

On my build video during the pinion assembly I explained how this is an important factor. The only amount of shims that are needed or the amount of shims that measure up to the amount of depth in the rear axle housing the additional shims are inserted on the outside of the outer bearing in between the C clip in the outer face of the outer bearing .... This prevents the pinion from moving back-and-forth no slop almost 0 deflection . Your illustration should’ve shown shims on the lower portion (below the green line) of the pinion in between the outer bearing in C clip ....and there is your dinner

 

[Spunkybob]

On my build video during the pinion assembly I explained how this is an important factor. The only amount of shims that are needed or the amount of shims that measure up to the amount of depth in the rear axle housing the additional shims are inserted on the outside of the outer bearing in between the C clip in the outer face of the outer bearing .... This prevents the pinion from moving back-and-forth no slop almost 0 deflection . Your illustration should’ve shown shims on the lower portion (below the green line) of the pinion in between the outer bearing in C clip ....and there is your dinner

Ok I understand that.
Is that on YouTube? I've watched your videos but I may have missed the assembly one.

So far the simple 3 bearing no grinding mod has been fine but every now and then I hear a slight bind usually after a bad landing or going from forward to reverse too fast.

I have a dremmel and my pinion fits in the chuck of my bench drill.

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[xwoop]

when torque is applied to the driveline, there will be a force repelling the pinion and bevel gear away from each other. In your picture, the pinion will try to slide downward, and never upward, when you are either braking or accelerating.

I kept using 3 bearings in my XL and it holds well. But I used castle ESC and tuned the torque down. In my opinion, 6S with a monster ESC plus castle 1515 will destroy any bevel/pinion gear if you are not careful with the throttle.

Even the standard non hd gears can take castle 1515 2200kv power if your gear mesh stays good and you have a slipper that works. But you really need to upgrade the driveline and build it carefully.

 

[BarHarborBasher]

Ok I understand that.
Is that on YouTube? I've watched your videos but I may have missed the assembly one.

So far the simple 3 bearing no grinding mod has been fine but every now and then I hear a slight bind usually after a bad landing or going from forward to reverse too fast.

I have a dremmel and my pinion fits in the chuck of my bench drill.

Sent from my SM-G935F using Tapatalk

At 14:07 https://youtu.be/yQCVe8W_6ag I give a full explanation of the order of shims

 

[BarHarborBasher]

Ok I understand that.
Is that on YouTube? I've watched your videos but I may have missed the assembly one.

So far the simple 3 bearing no grinding mod has been fine but every now and then I hear a slight bind usually after a bad landing or going from forward to reverse too fast.

I have a dremmel and my pinion fits in the chuck of my bench drill.

Sent from my SM-G935F using Tapatalk

At 14:07 https://youtu.be/yQCVe8W_6ag I give a full explanation of the order of shims

 

[Spunkybob]

Even the standard non hd gears can take castle 1515 2200kv power if your gear mesh stays good and you have a slipper that works. But you really need to upgrade the driveline and build it carefully.

I have the GPM drive shaft so at least that's strong.

At 14:07 https://youtu.be/yQCVe8W_6ag I give a full explanation of the order of shims

Thanks mate, I'll watch it when I have time.

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[Spunkybob]

At 14:07 https://youtu.be/yQCVe8W_6ag I give a full explanation of the order of shims

I just watched the video.. smooth as butter!
I'm going to have to order another packet of axial shims.

I wish In was in the US and I'd send you my pinion.. I'm sure I can do it myself but I'm worried if I stuff it up its $$

Does anyone make a 3rd party pinion that's already modded?

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[wdiabc]

Yes this is what I was thinking.. but if your jumping and land nose first won't the pinion slide forward too far? I suppose not because even if it does move a little it can never move further then what was designed by axial while not perfect won't implode.

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In the action you were describing, the pinion is so light and wont create much force at all. Don't worry about this minor issue

 

[BarHarborBasher]

when torque is applied to the driveline, there will be a force repelling the pinion and bevel gear away from each other. In your picture, the pinion will try to slide downward, and never upward, when you are either braking or accelerating.

I kept using 3 bearings in my XL and it holds well. But I used castle ESC and tuned the torque down. In my opinion, 6S with a monster ESC plus castle 1515 will destroy any bevel/pinion gear if you are not careful with the throttle.

Not true they will definitely handle 6s I’ve even ran 8s /2200kv with a c/d no issues... the reason you don’t have faith is because you’re not setting them up properly. The pinion should never have movement in any axis. I’ve gotten 100s of 6s only runs without issues. It’s really not even in my consciousness wile bashing anymore.

 

[Spunkybob]

Not true they will definitely handle 6s I’ve even ran 8s /2200kv with a c/d no issues... the reason you don’t have faith is because you’re not setting them up properly. The pinion should never have movement in any axis. I’ve gotten 100s of 6s only runs without issues. It’s really not even in my consciousness wile bashing anymore.

This is the kind of confidence only a man with a good diff can express!

One day I'll be this man.. one day ;-)

In your opinion is an aluminium rear axle a must?? I was either going to get that or the aluminium transmission housing.

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[BarHarborBasher]

This is the kind of confidence only a man with a good diff can express!

One day I'll be this man.. one day ;-)

In your opinion is an aluminium rear axle a must?? I was either going to get that or the aluminium transmission housing.

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No aluminum transmission,bulkhead or rear axle required for Reliable 6s performance. Just a BHB pinion mod, driveshaft boot & limiting straps.

 

[Spunkybob]

No aluminum transmission,bulkhead or rear axle required for Reliable 6s performance. Just a BHB pinion mod, driveshaft boot & limiting straps.

Thanks for that brother.

I got the aluminium bulkhead because after a few nose landing I didn't trust the plastic housing.

I have the boot dialed and I'll make some leather limiting straps and do your pinion mod with my 3 bearings.

What about the plastic transmissions that we see all melted?

I hate spending money when I don't have to so I appreciate your incredibly valued input.

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