Modified XXX-NT Dog Bone Problems

[Big Bear Tony]

I need some help. I have a XXX-NT with a .18 OS engine bolted to it. The buggy runs great, pulls wheelies on demand and I couldn't be happier. Well, maybe I could be a bit happier. I am having a problem with the righ rear dogbone staying inside of the transmission/dif. I suspect that when the shocks fully extend, the dog bone is traveling to far and it pops out of the cup on the transmission/dif. Can anyone offer suggestions on a fix.

 

[olds97_lss]

Weird... I ran a xxx-nt RTR as my first RC 7+ years ago and never had that as an issue. I broke a couple of the axle yokes and countless arms, but never had the axle come out of the diff cup unless I busted an arm or something.

Sure your pivot block isn't cracked or your arm isn't? Have you ever replaced the axle? Come to think of it... you said dog bone. Mine had a dog bone on one end (diff end) and a plastic u-joint on the other end (by the wheel).

Regardless, have you ever replaced the axle or diff cups? Maybe you got a wrong part?

 

[NCNitro]

I have had two, actually still have one, and that has never happened to either of mine.

 

[Big Bear Tony]

Thanks for your input. I have broken many arms but never the axel. I have ordered new dog bones and will install them next week when they arrive. I do have afer market shocks on tem and I am wonderig if this is causeing a problem. When the shock is fully extended, it pulls the end of the dog bone almost out of the cup. This is the drive wheel if I am not mistaken and might be the problem.

Weird... I ran a xxx-nt RTR as my first RC 7+ years ago and never had that as an issue. I broke a couple of the axle yokes and countless arms, but never had the axle come out of the diff cup unless I busted an arm or something.

Sure your pivot block isn't cracked or your arm isn't? Have you ever replaced the axle? Come to think of it... you said dog bone. Mine had a dog bone on one end (diff end) and a plastic u-joint on the other end (by the wheel).

Regardless, have you ever replaced the axle or diff cups? Maybe you got a wrong part?

I have had two, actually still have one, and that has never happened to either of mine.

The XXX-NT was my very first car when I got involved in the sport. I have 3 nitro cars and truck, including the Jato 3.3 and my XXX-NT is still my favorite. I have changed all of the tie rods over to Lungsford, gone to after market shocks, wheels and tires, and also changed the engine out to the OS .18 CVR. I have not been able to run the Losi up against the Jato, but I bet they are close. It will pull wheelies on demand and I love it. The only issue is this stinking dogbone.

Thanks

 

[olds97_lss]

Have you compared your after market shocks to the stockers to see if they are longer? If they are, they would cause a problem like this by doing as you suggested, letting the arms fall too far on full extension.

 

[NCNitro]

Have you compared your after market shocks to the stockers to see if they are longer? If they are, they would cause a problem like this by doing as you suggested, letting the arms fall too far on full extension.

And if that turns out to be the issue, you can fix that by putting a piece of fuel tubing inside the shock on the shaft under the piston to reduce the extension of the shock.

 

[Lessen]

And if that turns out to be the issue, you can fix that by putting a piece of fuel tubing inside the shock on the shaft under the piston to reduce the extension of the shock.

Ahh.. beat me to the punch yet again :thumbup: Great suggestion

 

[olds97_lss]

Or you could just try to adjust where the shocks mount on the towers/arms so they don't let the arm drop so far. The outermost holes on the arms and towers would effectively shorten them up a few mm's. Unless your already adjusted that way.

 

[Big Bear Tony]

Thanks

Thanks for all of the posts. Last night I spent the evening putting my Jato 3.3 ack together and tonight I plan to work on the XXX-NT. I am almost posative that the shock is causing this issue. I'll try some of your suggestions and see what happens.

Again, a big Thank You

 

[NCNitro]

Good luck, let us know how you make out with it.

 

[olds97_lss]

Did the shocks come assembled? Did you put the ball ends on? If not, then you might just want to check and make sure the ball ends are screwed on completely. I bought 8 brand new shocks off ebay that were for RTR OFNA 9.5 buggy. None of them had the ends screwed on all the way and they were all at different lengths. A few of them were only screwed on a few turns. By the time I screwed them all completely on, some had changed length 3-4 mm.