Steering box- what stops steering?

[WJACKSON11X]

I'm replacing some seals on my box while doing hydro assist. I'm using a JKW offroad end cap and drilled/tapped top cap. I removed large snap ring for end cap, then turned steering wheel to the left until the cap popped off. What causes steering to stop before piston reaches the end cap? The only reason I ask is because I did have a JKW end cap on, but had the hole plugged until I did hydro assist. While driving on my last outing, i blew the end cap off of the box, ruining the cap and box. So, I'm wondering what caused this to happen. Is there something that is supposed to stop the piston. I know there are stops on the knuckles, but don't want to break a knuckle either. I was cycling the steering with end cap off and the sector shaft was hung up, not allowing me to remove it. I finally was able to remove the shaft, but got to thinking about this whole thing. Sorry for the long and confusing post. I'm trying to keep this from happening again.

 

[Leadfoot]

What were you running for a pump and/or pump mods?

Blowing the end cap off takes a TON of pressure. Assuming the cap was machined correctly the only other thing would have been a weak retainer ring (I know some guys hose them accidentally when trying to remove them to put the new cap in). It becomes weakened and they try to reuse it with catastrophic results.

 

[4X4HIGH]

If the steering stops on the knuckles aren't adjusted properly then the end cap becomes the stop at that end of the box and the inside casting of the box becomes the stop at the other end. Also if you're not careful when removing the end cap by turning the steering shaft to push the cap out you'll end up dropping all the recirculating balls out of the rack nut and then find yourself trying to put it back together again after removing the sector shaft and cover.

 

[WJACKSON11X]

I was running stock everything. Could air in lines cause the blowout? I was having trouble bleeding the system at the time. I made sure to not mess up the snapring this time, although not sure about the last time. Thanks for the input, just trying to prevent another blowout.

 

[Blue85]

Did you have the end cap off prior to this blow-off? Maybe the ring wasn't seated correctly, like with junk in the groove or something. With a drilled and tapped end cap, there must be a plug or fitting in there and the piston is hitting that. An unmodified gear at standard pressure is OK with bottoming out in either direction. In general you should have the linkage adjusted so the knuckles hit the stops before the box bottoms out, but obviously all of that changes as the front axle is articulating. So bottoming the box out will happen sooner or later - it has to be OK with it.

You might also check the pump to make sure it's going into bypass when it should.

 

[WJACKSON11X]

I had just replaced the pump and installed JKW endcap, but had a plug on it at the time (no hydro assist) just before the blowout. It could have had excessive air in system I guess. I had also installed a cooler and had a hard time with bleeding the system. I'm thinking that had a lot to do with it. I should be able to finish the hydro stuff this weekend. Hopefully everything goes smoothly.

 

[andyblack]

I say turn the stops on the knuckles out a bit just to make sure.