Bilstein 6112 Failed?

Long story short after welding together a steel bumper and adding a winch I decided I needed to go up in spring rate from the stock 600s. I pulled the 6112s and took them to a shop to have the coils swapped since I do not own a wall mounted spring compressor and doing it with the shock in the truck is kind of sketchy for me.

Upon disassembly the tech advised me the top hat nut was rusted and seized to the shaft so he attempted to use impact on it after using solvents however this caused the shaft to unthread out of the shock spraying oil everywhere. The shop is saying these 6112s aren't rebuildable so I have to replace them now. I've read these can go up to 100k trouble free miles before they show signs of aging but mine only had 37k miles. Top perch setting though would constantly give harsh top outs which may have contributed to early failure or was this a mistake when tech was removing coil?

I thought if the top hat nut is seized bad enough there is a way to clamp the shaft to stop it from spinning when removing the top hat to prevent from this happening? The tech said he didn't do that and just use the impact gun on the top hat while the shock was in the spring compressor. The threads on the end of the shaft are undamaged so is there a way to thread the shaft back in and pressurize so I can get my truck back on the road or is it time to upgrade to 8112s?

If this was indeed the tech's fault I am partly to blame for taking it to a shop that isn't experienced in off-road vehicles but it's not a hard job and something I could have done at home with the right tools. Shock was not showing any signs of failing prior to this although the bushings at the bottom are no longer in the center, it might have been time to replace them anyway?

 

Cheap enough to replace shock.
Good luck

 

Might have been better off putting the heavier springs on new shocks to start with.

 

Ended up ordering Fox 2.5 Performance Elites (883-06-178) with the aluminum body for corrosion resistance which is much needed where I live. Hopefully have them by this Friday! Apparently these Bilstein #650 springs will work on the Fox 2.5 so I think I will start there and maybe go up to #700 later if it's not enough. I have a 150 lb steel bumper with 75 lb winch as well as all steel skids (engine/trans/t case) as well as rock sliders. I also have roof rack with 2 awnings and a 7 gal water aluminum water tank as well as a Pelican case on it so about as heavy up front as you can get.

 

FWIW, you’re supposed to put an open ended wrench on the end of the shaft before loosening the nut on the threaded portion below it. The tech destroyed that 6112 by using an impact on it. Some heat with PB blaster would have probably done the trick in your case but all said and done, you’ve ended up with an upgrade out of the debacle.

 

Some Bilsteins use a 5mm Allen key in the top of the shaft which is not obvious and not as strong. But it looks like these have wrench flats.

I had a factory shock that was so stuck that I destroyed a pair of vise grips getting the nut off. It's kind of a bad design to have a nut that tightens with no positive stop (shoulder on the shaft). Makes it easy to go too far and destroy the nut and the shaft.

 

I'm with you. That tech destroyed the shock. That definitely was supposed to have a wrench put on it...

 

Grab an adjustable wrench for the top of the shaft and a 18mm (pretty sure that's the size) for the nut and see if it breaks free. You will know right away.

It doesn't look like its that bad to me. I have only come across a couple of oem shocks that seize in that spot, and they looked a lot worse than yours. Never a 6112 before.

 

you never use an impact to remove a shaft nut on anything regardless if its an offroad shock or not because this can happen. ive seen it many times now. like others have said top of shaft has a flat where i found vice grips work the best to hold. if nut is really siezed on there i get a carbide burr and grind away the nut hurting threads as little as possible. this is the techs fault for destroying the shock.