Blackfoot Rear Axle - help needed

[Rebuild 4]

Just built a 2016 re-release of Blackfoot.  It is running great, but the swing shaft keeps popping out of the gearbox joint, on either side randomly, one at a time.  Today, one of the black plastic pieces C6 or C9, that holds the axle and hub, popped out of the gearbox where it meets it.  The swing shaft (dog bone end) does not seem to go too far into the gearbox joint on either side of the truck.  Does it need tightened up?  Is there a way to prevent it from happening?  Thanks 

[DonLawson84 1]

I had the same thing happen and contacted Tamiya.  They sent me gearbox spacers and new shafts that were a different style, I believe they were 2 piece when the original is one. 

[tamiya3speed 464]

Don, any pics of the parts they sent?  This is a fairly common issue with these and I wasn't aware Tamiya had any fix for it.  If there are other shafts available I'll order a whole bunch!

[Rebuild 4]

Was it this from tamiyausa:  56043 gearbox spacer?

[DonLawson84 1]

I found the old email, but it does not have any part numbers.  They just sent me a bag of parts and this diagram on where to put the shims.  I believe the axles were from a frog.  I have since added a spacer  (m6 washer) between the rubber o-ring and the first U joint that sticks out of the gearbox photo attached. 

[Andyrt200 201]

My original has had the frog drive shafts since the Frog re-re came out. 
I found shimming out the drive shafts can cause the suspension to bind mid way up when the distance between the wheels axles & drive cups is shortest. 

I converted the trailing arms to run on bearings so they move more freely but are held in place much more firmly. The plastic pivots wear over time allowing the trailing arms to move out so the drive shaft pop out even more frequently with age.   

Its a bit of a fiddle, the smaller (850 I think) bearing fits the thin end perfectly but I had to make a spacer out of an old hornet gearbox for the fatter end. There is a bit of old TX arial to to keep the inner bearings held in against the outer, the outer is braced with a washer against the stock end cap with hole drilled very carefully in the centre. The bearings have to sit in the exact perfect place to be held tight so everything needs cutting very accurately. 
I also cut threads onto my new shaft the bearings sit on just to hold it in place, but that’s not essential, it only needs to be held in place, push on star type fixers would probably work for that too.

With the old frogshot diff mod it works very well!
 

https://youtu.be/9GJyslBQB2I

[Frog Jumper 3663]

 

Previous thread about this. Search around. The solution is on here...

Terry

[Rebuild 4]

thanks everyone!!