Need Help!

[WRX821]

Got a huge problem and need some help from you shafty guys.

First let me apologize for being a clod driver. Sorry.

Second sorry there are no pics but the veterans of this site will hopefully be able to figure this out with there pure wisdom.

So here is the scoop:

My brother-in-law is has been working on turning a TXT into a rock climber. We finally got together this weekend to try our respective machines out. Due to the nature of mine (clod type, rc guy pro 60/40 chasis with all the goodies) I kicked his butt. It became apparent that there was some serious issues with his truck. I mean why else would a clod walk all over a shafty right?

The shafty has aftermarket links that are mounted in the stock chasis locations but have been mounted to the top of the axles as per all the advice I recieved through numerous searches on this forum. (Read as I did My friggin searches before posting and asking for help) The top links are mounted together using a custom made top link mount much like that of a clod. This truck did not have the stock roll links (sway bars I think) installed. The truck has revo shafts in it and there is no bind in the drvie train. The axles are locked and the ride height is stock. The servos have been moved to the top of the axle in front of the top link mounts via custom servo mounts. Steering links are stock and do have some flex in them

Lathe motors and good electronics are onboard. So there is no issue there.

The truck operates correctly with regards to all control inputs.

I did not get the wheel base measurement and should have but it slipped my mind.

When the truck is run up against a step or rock, the chasis flexes causing the rearend to go in a different direction than the frontend. Kinda like it is trying to pass it. The chasis seems stiff if you pick one axle up and shake it side to side. But as soon as it tries to climb anything it gets all torqued up. We have tried numerous fixes to no avail such as: Moving shocks from stock location to mount from the chasis to the lower links. Moving shocks so they mount from the chasis to the top of the axles. No Luck. What gives?? This thing gets either all torqued up and rolls over or just flips over onto it's back when trying to climb.

Any advice would be nice because he is really into the shafty type rig and if he/we can not get it sorted I think he will bail on the hobby frustrated and beaten. Plus you shafty types do not want to see one of your own go clod do ya?

Thanks in advance for your help aned if you need more info ask and you shall receive.

[hondaracer]

tell him to go maxx.nothing else . maxx

[mike]

Sounds like the triangulation in your links is wrong. Get some pics so someone can point you in the correct direction.

[WRX821]

Hondaracer...need solutions not new problems.

Mike,

I will try for the pics. I know it is tough to solve without pics, but no pics is what I have right now.

How far off can the triangulation be to cause major issues? I looked at the trucks on this sight and made the corrections to his truck to try to resolve the issues but no luck. If a four link system is used and mounted to the stock holes in the chasis and the ends are mounted with the bottom links on top of the axles and the top links centrally mounted, could the geometry be that messed up? Could moving the bottom links out towards the ends of the axle be better?

Thanks,

[badger]

Originally Posted by WRX821

This thing gets either all torqued up and rolls over or just flips over onto it's back when trying to climb.

You will never completly get rid of this problem with a shaft. Here are some things you can do that will help:

1. Run a 60/40 setup
2. links triangulated properly
3. run a stifer spring rate in the left rear shock to help iliminate some of the torqe roll
4. run bb's or lead shot in the front tires.
5. mount the battery to your front links.

Basically if you make the rear longer, add more weight to the front axle and mount your battery as low as possible the rig will climb much better.

[Don]

Originally Posted by badger

You will never completly get rid of this problem with a shaft. Here are some things you can do that will help:

1. Run a 60/40 setup
2. links triangulated properly
3. run a stifer spring rate in the left rear shock to help iliminate some of the torqe roll
4. run bb's or lead shot in the front tires.
5. mount the battery to your front links.

Basically if you make the rear longer, add more weight to the front axle and mount your battery as low as possible the rig will climb much better.

Badger is right.
Shaftys have alot of torque twist. And when they get loaded up they tend to wont to roll to there right. I run stiffer springs in the rear to help this. I also find that having the top link parallel to the ground helps.
As for rolling over backwards: I run 9 oz. of BB's in the front tires. I also like to mount my Batt. on the front axle. And I cut the bottom of the chassis and raise the tranny up in the chassis and flip it around so the motor is to the front. Lower the ride height and get as much weight as low as I can. Is he running a GD600 or not? If he is running a GD600 he can clock it so the motor is in the center of the chassis. I have one TXT with the trans and GD600 clocked so the motor is on the skid plate.
As for triangulating the links: If you run the lower links parallel to the chassis or wider at the diff's and the upper links to the center of the diff's it should be fine. I mount my lower links on the outside of the chassis on the chassis end.
I hope this helps.

[WRX821]

Don and Badger:

Thanks to both of you for the suggestions. I will give him the info and see what he can sort out. It sounds like we might need to run the lower links a little different than they are set up. Moving the bat forward will help to be sure. I will try these and let you know.

It is nice to know that the torque is an ongoing problem and we are not the only ones with issues.

Thanks again,