Added Metal Diffs and Slipper Clutch with 15T pinion. Now wheels lock with no throttle

[Billy Magic]

Hi Everyone,

I'm in the process of completely upgrading my Granite 3s BLX's drivetrain. As the post states I recently put in the Hot Racing front and rear metal diffs and upgraded the composite slipper clutch gear to steel. I also added in a 15T pinion.

My current situation is that when no throttle is applied, the wheels completely lock. There is no roll at all. As a result I keep either
A: lose tension in the slipper clutch or
B: cause the pinion to loosen around the motor.

I have double and triple checked the diffs and they work normally, great even. I used 50k in the diffs but I don't think that would make the difference. It's some problem between the steel spur gear and the pinion IMO, but I can't figure out what's going on. The gear mesh seems perfect to me. I use the "paper" method and it looks good. I've changed this kind of stuff out before on my Notorious without issues so I know how it's supposed to go.

At this point I'm wondering if it's a motor or esc issue. Anyone had a problem like this before or any suggestions?

Thanks in Advance!

 

[Yas]

Can you upload a video, or link a YT clip of the problem?

When you take the motor out, do the wheels roll freely?

 

[KingKeif]

Does the car roll normally without the motor installed?

 

[Da Spanky]

Does the car roll normally without the motor installed?

same question, but sounds like you may have put the diffs or at least one in the wrong way, which means they are gunna fight against each other

 

[Billy Magic]

Hi guys,

Thanks for the replies. I'll upload a clip a little later. Right now the car is missing a center driveshaft and I'm in the process of getting one delivered. I know the diffs aren't working against each other because the locking occurs even if I'm only running the back wheels without the center driveshaft installed. Pretty sure you can't put the diffs in wrong since they only fit in the case one way. It rolls normally without the power module attached.

I suppose I could try disconnecting the pinion or taking out the motor and see how it rolls with just the slipper and center driveshaft installed. I definitely feel like it's an issue between the slipper and motor though.

 

[slick2500]

same question, but sounds like you may have put the diffs or at least one in the wrong way, which means they are gunna fight against each other

I don't think you can put the diffs in the wrong way on a 3s. The diffs will only fit one way in the yolk and the yolk only fits one way into the chassis.

Is your motor pinion and spur gear mesh set properly? Proper gear mesh the gears should click a little bit and not be super tight together.

 

[Billy Magic]

Hi folks,

Just to end this thread I discovered the issue finally and as usual it's the simplest explanation. I was screwing in the three screws that hold the power module together too tightly and it was causing the spur gear to rub against the plastic. Once I backed off on tightening them so hard, the gear and pinion spun down normally after I took the throttle off.

Very happy it wasn't something that was going to cost more money! My new center driveshaft should be arriving today and I'll take it out for a spin and see how everything's holding up.

Thank you for your suggestions. Love that this forum is so active.

 

[Yas]

Hi folks,

Just to end this thread I discovered the issue finally and as usual it's the simplest explanation. I was screwing in the three screws that hold the power module together too tightly and it was causing the spur gear to rub against the plastic. Once I backed off on tightening them so hard, the gear and pinion spun down normally after I took the throttle off.

Very happy it wasn't something that was going to cost more money! My new center driveshaft should be arriving today and I'll take it out for a spin and see how everything's holding up.

Thank you for your suggestions. Love that this forum is so active.

I'm glad you found the cause! Although you should still have the power module tightened snug and not left slightly loose

You should get some 15x12 shims to space the spur gear/slipper assembly away from the plastic housing. Check this thread out - LOTS of info in here:

Post in thread 'BLX Motor' https://www.arrmaforum.com/threads/blx-motor.20999/post-290243