[Solved] First two minutes driving, lost front power

[beandog]

I just got my MT410 up and running tonight. 4S, 20 tooth pinion, 2250kv motor, what I thought was a pretty modest setup.

After running it around the front yard, no jumps, no big crash, the front totally lost power. Turning one front wheel still causes the other to turn. Turning the motor causes the front drive shaft to turn, but there’s no connection between the main front drive shaft and the wheels.

I’m not excited about tearing this thing apart after spending ten hours building it... what’s the easiest way to get at the front diff? I’d expect the wheels to not be connected with each other at all if the diff blew. Maybe the gear in the front gearbox stripped somehow? What could have gone wrong?

It’s terribly frustrating on my first Tekno build ?

 

[Nicochau]

Very surprising. Did you threadlock the diff coupler (TKR5075)? Threadlock needs to sit 24h before use.

 

[beandog]

Pretty sure, yeah, I thread locked everything marked in the manual. That part of the build was several days ago.

 

[Nicochau]

Open the front gear box. Check the diff gears and make sure there is torque transferred to front diff pinion.

 

[lampshade9909]

Pretty sure, yeah, I thread locked everything marked in the manual. That part of the build was several days ago.

Check the diff coupler again. Take the screw out and apply thread lock again. Make sure to shake it well first. This same thing happened to me one time. The problem wasn't that I didn't apply thread lock, but was that the threadlock didn't stick. I later realized that I was supposed to shake the threadlock before applying. The same thing happened to a few other screws i thread locked (because I didn't shake it first)

 

[TBuggy]

You should also clean the factory oils off of the screws first before applying thread lock to new screw. Simply wiping them down with an alcohol wipe ahead of time will make a huge difference.

Something tells me that the previous suggestions of the couple being loose is probably the issue. When you snugged up the grub screw on the coupler did you make sure that you had it positioned to line up with the flat spot on the diff pinion?

 

[beandog]

Yes it turned out to be simple, just the coupler somehow came off the indrive on the front diff. There's a spot of blue on the indrive where the screw touched but somehow I must have messed it up. Fortunately no damage, I'll be back up in no time. Thanks everyone for weighing in!

 

[Overkill]

https://www.teknoforums.com/threads/set-screw-coming-loose.1375/