Steering bind after changing to the HD Gear in front axle

[BrotherAndySLB]

I know many people suffer from steering that binds at full lock or near full lock. I didn't... Until I installed the HD Gear in my front axle.

I've read threads that say the axles are 90 degrees off, so I took the axle out turned it 90 degrees put it back in. No change. Took the other side out turned it no change... So took the original out and turned it one more time, no change.

Has anyone officially figured out what causes this? Mine didn't start until I took it all back apart and installed the hd gear.

[Natedog]

Make sure that both front axle shafts are in phase with each other, I put one drop of Tri-Flow telfon lube on each CVD occasionally, work it in and wipe off excess. I do the same on the driveshafts and CVDs of all my crawlers. The joints need a little lube to keep them smooth and longer lasting...no matter the brand...this truck has lots of steering throw therefore any binding is much more noticeable. Mine work fine.

[BrotherAndySLB]

Thanks,

I'll try and lube up the CV joints. I don't want to But I guess I can take the cover back off the axle and make sure the axles are in phase. My axles are full of Marine Grease so this ought to be interesting

[SilmarilS]

You don't have to open the diffs to lube the CVD...

[BrotherAndySLB]

I'm opening it to make sure I have the axle shafts in phase with one another.

[Natedog]

You don't have to open it, just turn front wheels to left, observe and note the cvd cross-pin orientation (and large or small pin, there are two per cvd), then turn the front wheels the other direction and check that the large or small pin is in phase with the other side. It can only be 90* off phase, the inner axle ends are square and fit into the square hole in the ring gear/spool. Also make sure that the driveshaft ends are in phase with each other.

[BrotherAndySLB]

Follow up. I did go ahead and open the axle. I removed a lot of the marine grease I had in it... But, on to the important stuff.

Do you ever wonder why vaterra gave us axles that take set screws but didn't put set screws in them? ( in my case they didn't include any in the kit and its not in the instructions ).



Also, look close at this axle I think this is my problem, well at least it's going to be a problem.



Yeah, it's cracked... I added a set screw to this side to see if it'd make a difference...

I greased both CVs put it all back together

And? The bind is gone. It probably just needed the CVs greased you can see in the pictures the dry rubbing that was going on.

All better now, guess I need to get a new axle.. What do y'all think about the lack of set screws, put one in the other side or leave it be?

[EeePee]

Pretty much don't need set screws with the retainer rings.

[Natedog]

Glad you got the bind sorted out, just needed a drop of Tri-Flow once in awhile on them. Don't need setscrews as EeePee said, the retainer rings are better, taht way all the bearing surfaces of the joint float against each other...longer wearing and smoother if you keep a little lube on them. I always buy and carry in my pack spare CVDs for all my crawlers.

[Yeti.stealth]

Originally Posted by BrotherAndySLB

I know many people suffer from steering that binds at full lock or near full lock. I didn't... Until I installed the HD Gear in my front axle.

I've read threads that say the axles are 90 degrees off, so I took the axle out turned it 90 degrees put it back in. No change. Took the other side out turned it no change... So took the original out and turned it one more time, no change.

Has anyone officially figured out what causes this? Mine didn't start until I took it all back apart and installed the hd gear.

Hi guys,
I had exact same thing happen, never solved it by experimenting with axle phasing, lube, drive shaft phasing etc. with the phasing set up correctly it would still " bind" while driving at full lock, worse in reverse. I just learned to live with it being a newb to crawlers...seemed to happen around the same time I fitted hd pinions and drive shafts but I think it was just coincidence.

Is your rig RTR with stock steering servo?

I just replaced the RTR servo with a savox 1210SG water proof and the plastic 25 tooth servo horn that's included in the RTR kit and instantly the steering wobbles or "bind" have disappeared!

My stock Rtr servo output was getting very wobbly and seemed to be getting weaker and weaker, I believe that it had become so weak that it was unable to hold position and was being overpowered by the small amount of bind at full lock.

As a crawler newb, the 1210 servo seems to me to have 1000 horsepower compared to my old weak wobbly RTR servo, I can only imagine what the higher torque servos on a higher voltage must be like.

So if your having no luck eliminating the steering wobbles, it my be a weak steering servo.

[BrotherAndySLB]

No, mine was a Kit Build. I run a Solar D772 hooked straight up to the balance plug of a 2s battery. Lube in the CVDs got rid of my issue.

[Natedog]

Originally Posted by Yeti.stealth

Hi guys,
I had exact same thing happen, never solved it by experimenting with axle phasing, lube, drive shaft phasing etc. with the phasing set up correctly it would still " bind" while driving at full lock, worse in reverse. I just learned to live with it being a newb to crawlers...seemed to happen around the same time I fitted hd pinions and drive shafts but I think it was just coincidence.

Is your rig RTR with stock steering servo?

I just replaced the RTR servo with a savox 1210SG water proof and the plastic 25 tooth servo horn that's included in the RTR kit and instantly the steering wobbles or "bind" have disappeared!

My stock Rtr servo output was getting very wobbly and seemed to be getting weaker and weaker, I believe that it had become so weak that it was unable to hold position and was being overpowered by the small amount of bind at full lock.

As a crawler newb, the 1210 servo seems to me to have 1000 horsepower compared to my old weak wobbly RTR servo, I can only imagine what the higher torque servos on a higher voltage must be like.

So if your having no luck eliminating the steering wobbles, it my be a weak steering servo.

Thats a great point and after thinking about it I agree on the steerimg wobble, mine was never terrible, but it's better after swapping in a bearing on the stock servo output shaft.

[Yeti.stealth]

I have been thinking about the binding at full steering angle a bit more, why does it suddenly appear after someone has done some work on the front axle? The wobble or bind wasn't there or wasn't as severe before right?
So you check that the the slots in the CVD's are in phase, easy to do, set the truck on the work bench and give it full lock, drive forward until the slot in the ball of the CVD is visible and level with the table top. Now give it full lock steering in the opposite direction, without moving forward or reverse, and check the slot in that side is visible and level.
Now you check driveshaft CVD slots are in phase, and they are ok.
Now we add a bit of lube to the CVD's and it seems to reduce it a little maybe. But it's still not as good as it was before.
Recently I installed a higher torque servo and that has reduced the wobble some more. But I still think there is something else going on.
I was tinkering with my RTR rig tonight and discovered that my driveshaft CVD's are in phase with the front axle CVD's, every second rotation, due to the 2 to 1 diff ratio. So with this in mind at full steering angle I will have both front CVD's hitting their "tight" spot at the same time both drive shaft CVD's hit their "tight" spot.
Solution was to pull the diff centre and rotate it a few teeth then Ramesh with the pinion, now my driveshaft joints are out of phase by about 45 degrees with the front axle joints.

A quick test on the floor doing tight circles and it seems a little better again. Pretty good actually. I will experiment some more another day.

Has anyone else tried this? Maybe something else to try if your experiencing a bit of binding at full steering angle.

[Yeti.stealth]

Got a theory about the sudden appearance of the steering bind, it's unproven but maybe if the front drive shaft CVD is in phase with the front axle CVD's and because of the 2 to 1 diff ratio it will always be in phase every 2nd rotation. This means at full steering angles the axle CVD's will hit their tight spot the same time the drive shaft CVD's hit there tight spot ( only talking small drive shaft angles ) but the 2 combined might be enough to create the wobble.

Only way to change drive shaft to axle phasing is to pull out the axles and pull the diff centre out and rotate it a few teeth with regard to the pinion gear. The sudden appearance after installing HD pinion may just be unlucky chance alignment.

I pulled my diff out and reinstalled it to give a 45 degree out of phase drive shaft CVD to axle CVD's and I think it has smoothed out the wobble I bit more and because of the 2 to 1 ratio it will always be 45 degrees out.

[Yeti.stealth]

Sorry for the double post. Posted the first one days ago but it never appeared? So rewrote and posted again, now both posts appear!

[Natedog]

No problem it's good information and sounds like probable cause. Thanks for posting your findings for all of us.

[Johnnysplits]

Originally Posted by BrotherAndySLB

I run a Solar D772 hooked straight up to the balance plug of a 2s battery

How's that wired? Have a pic?

[BrotherAndySLB]

Well, not really.



See the balance plug hanging down? I would simply just plug that in to the 2s female balance plug. I changed my setup on Thursday so theres no way I can get more detailed pictures but this is what I did:

Get a servo extension wire and a balance plug extension

On the Servo Extender Cut the red wire off of the side that goes to the receiver or pull it out then cut it either way. Cut the black wire a little over mid way, you want to make a Y in the Black wire
On the Balance Plug extension, cut the side off that doesn't plug into the battery, remove the wire that isn't red or black, connect the red wire to red wire on the servo extender, connect the black wire to the Y section of the black wire on the servo extension. Use good solder, and heat shrink tube.

The reason I use a Y on the black wire is because if you use two different batteires your Servo will not work if Both are not grounded togethor. The Solar D772 can run off of the balance plug (8.4v to under 7 volts) with out any issues.

My new setup is a castle BEC set to 7.4volts wired straight to the battery connector on the ESC, then setup the same way with a servo extender (black still has a Y in it. It just works better this way). The Castle BEC fits inside of my waterproof box with my receiver so wires are a lot more tidy this way. Plus I don't have to run more than one battery, before I was running a 2s ontop of a 3s.

[Johnnysplits]

Thanks!!!