Buffer Assembly on XT steering linkage.

[ImminentFailure]

I got my XT out of the box yesterday and went through all the getting started stuff. Finally got around to wanting to break it in today and I have a steering problem.


I'm able to freely turn the tires and linkage by hand (via grasping the wheels) and they move fluidly with low resistance. When the XT is on the ground, they wont turn. I first thought it was servo torque, or travel issues (hearing about the weak server on this forum), but I noted that the server is traveling its full range of motion. If I lift the front end up, the wheels turn full side to side no problem via servo.


On the exploded view of the manual I saw there's a buffer assembly (07121). As the servo engages, the tapered collar rides up out of the bottom assembly, engaging the buffer spring. I appreciate the mechanics behind this for absorbing jolts, and the such without snapping your linkage, but at this point it's prevent the car from turning at all. I figured maybe forward rolling would assist the steering, so i had her get crawling at 5mph, tried to turn, nothing.


Has anyone had any issue with this or suggestions?


From the user manual it looks like A LOT of stuff has to come apart to adjust. Too tight to get tools in there, or barely fingers onto it with enough torque. I Couldn't get it to tighten or loosen. This is a bit frustrating for my first attempt at using the XT.

 

[ImminentFailure]

Got apart what was needed. Took a pick of the little bugger.


It's completely seized up, can't tighten or loosen. My weekend of fun with an RTR 1/5 has turned to anger lol.

 

[Deluge]

They probably put some thread locker on it. Heat it up with a soldering iron and break it loose.

 

[ImminentFailure]

I suspected that after a bit. I was able to break it free after warming it up. I took the entire assembly apart so I could get some good torque on it.


I'll just have to play with an optimal setting that provides buffer protection, without the steering hinder.


There was far less to take apart then I thought to get at this. I thought the top plate was tied in. Was just a matter of 5 screws, so if anyone else has this issue in the future don't be to scarred.

 

[ImminentFailure]

welp, put it all together and even with it tightened way down still rides up and barely turns the wheels.


Also in the first minute of driving it the screw in the bottom of the steering mount fell out (part 07127) and that top hat looking thing fell out god knows where. I see they only come with the steering mount kits, maybe I'll give redcat a call see what they can do because this is pretty crazy.


Also the manual shows on page 5 the flanged edge of that 'top hat' bushing mounted inverse from the way it's installed on mine. Wondering if I should flip that around.

 

[DemonRC]

Move the steering linkage down a notch on the servo horn. It's too high. I've done a mod to reverse the mounting position so I can mount mine really low to give me extra torque to turn the tires. A buddy of mine with an XT could turn his tires with the car on the ground when he did the mod.

 

[ImminentFailure]

Thought I'd throw out an update here. The bushings that insert into the steering mount on the top and bottom were installed from the outside in. In the manual they should be inserted into the outside steering mount from the inside out, before inserting the inner steering mount. View attachment 4137 This creates a metal buffer between the two steering mounts and reduces and bindings. There's clearance for this bushing between the two steering mounts. After correcting this issue from the factory, my steering is pro. I actually have no problem with the stock servo torque. I bashed it around for a while with no issues.



/monthly_2011_06/steeringmountbushing.jpg.bf9853299e3d24e3b0bdd6b8fe0243f7.jpg

 

[jinda]

I got my today and did a "nut", "bolt" and assembly check.


I also saw that I was assembly incorrectly. I can't get #07174


bolt out. Any ideas? I never ran this truck or even put fuel in it.


Later JeReMy

 

[DemonRC]

Yes that bolt can be a major PITA to get out. It goes into a Tee nut that is mounted inside the steering knuckle. The Tee nut has a special flange on it to not spin inside the knuckle. The problem is the bolt is locktited into the Tee nut so tight that the Tee nut will spin and strip out the plastic that is supposed to hold it in place. You can try removing the entire assembly and get some needle nose pliers in there to hold it. This is VERY difficult to do because the CVD is in the way. What I ended up doing was using needle nose pliers to break off the flange of the Tee nut. The metal is very brittle and you can just snap off the edges. Then you can pull the entire bolt through with the nut and all. The problem is that you have to replace the Tee nut with a new one but they cannot be bought seperately. Ace Hardware has some wood Tee nuts to fit that bolt. You have to dremel the flange down some and cut off the points that grab into the wood. The main cylinder is the perfect diameter to fit into the bushing holes too. My other method to getting the bolts out is to cut the son of a bitch out by hacking the whole knuckle apart! This is the prefered method after an hour of frustration and a dozen beers.


The solution to the entire problem is to grab the alloy knuckles from 7075RC. The bolts thread directly into the knuckles which is nice. You also solve the bearing problem at the same time.

 

[ImminentFailure]

Two bolts on the left wheel and top on the right were loctite'ed in, the bottom one was not and why it fell out on me. Usually heating up the screw with a soldering iron works. I just used a large T style hex wrench vs. large amount of torque and was able to break them free. Clean out the threads and re loctite them in after you change around the bushings.

 

[jinda]

That answers the question. Thanks!


Where is this in the instruction manual?


I looked over and I don't see it. I never would have


tried to remove it if it was assembled correctly.


Later JeReMy

 

[ImminentFailure]

The bushing installation is on page 5 if that's what you are asking. I included a thumbnail in my post a little bit up the page. Click on it for a larger picture.

 

[jinda]

Where does it show the Tee nut that is mounted inside the steering knuckle.


Most RC car instructions have a note to locktight or not.


Sometimes there is just a statement saying locktight all metal to metal conections. If is saw that there was a tee nut I would never would have


tried to remove the bolt. Know I have a "f"ed up steering knuckle.


What other "not shown" parts are there? I really don't like trying to


fix something and making it worse.


Later JeReMy

 

[ImminentFailure]

It doesn't show it, it's just how they mount a metal thread stud into a plastic molded knuckle. Just like a hela-coil. Three of mine were loctite'd in, they broke free just fine without rotating the threaded mount. I'm talking about the M5*13 cap head screw 07174. You should have to touch anything internally regarding the inner steering mount itself).


You pretty much wanna blue thread lock any metal on metal screws. The grub/set screws in the drive shaft, and the brakes (covered in other threads) as well as these steering mount screws after assuring the assembly of the bushing is correct (that's the T-shaped or top hat looking collar).

 

[jinda]

Three of mine were loctite'd in, they broke free just fine without rotating the threaded mount.


They did move, but they did mess up the steering knuckle.


You pretty much wanna blue thread lock any metal on metal screws.


Yes! you are correct blue loc-tight on small screws. If the instructions


where correct, I would have known it was there and had loc-tight.


So I wanted to try it out. So what the bushings are up side down.


1 tank off the ground for brake in. Then 1/2 tank driving slow


Got a little speed wobble. So I looked it to it.


8 bearings shot!!!


They are too small I also think they were bound up from the factory.


The car did seam to roll fine!. But friction builds up.


Later JeReMy


Later JeReMY