How can I secure a post to a conversion ball for a shower faucet?

Question

I have a Delta single-handle faucet. I installed a conversion kit about half a year ago to update its trim from a knob to a lever. It's been great until yesterday when my wife complained that no matter how she maneuvered the lever, only scalding hot water was coming out of the faucet.

I took the assembly apart and discovered that the post which connected to the conversion ball was loose:

---

---

I tried tightening the post by hand and even with a wrench, but it quickly came loose again once it experienced the torque of the lever.

I checked with local plumbing supply stores and they don't carry the part. I'm wondering if I can fix it temporarily (for a week, say) while we await the new part. The post is secured to the ball via a short thread. Perhaps there's a suitable thread locker for this application which can withstand the torque and water? I tried JB Weld but that failed miserably. Both the post and the ball are made of steel.

Answer 1

I am sure that this can be fixed with a thread locker material. There are products available that can be placed onto threads before assembly and then will cure into a very tight joint to keep the threaded fasteners from coming loose.

You can get this at almost any auto parts store. Ask them for "loctite" thread locker.

Before trying to use it clean out the threads in both the ball and on the stem piece. Since you already attempted to use epoxy on these parts it may require extra diligence to clean out the thread grooves. Wash the parts in something like rubbing alcohol and then let dry well before applying the thread locker and reassembling.

Let the locker fully cure before attempting to put torque on the stem and ball assembly.

(Note that I have no affiliation with the LOCTITE brand other than a user).

Answer 2

Your picture shows parts that are for a knob style handle. You say you changed to a lever handle which should use a cam with a rounded triangular hole rather than the pictured "slot style" cam. Also, the ball for lever handles is different than that for knobs. It has a slot in the side of the ball that engages with a small pin which protrudes from the right side of the faucet valve cup body. The pin/slot is required because it limits lever handle travel.

Lever handles with the proper cam and pin/slot do not exert torque on the ball/stem assembly because the movement to adjust temperature and flow does not involve a twisting motion (like it does with the knob/slot-cam assembly).

When you repair the faucet make sure you get the proper parts for the knob to lever conversion: pin, lever style ball with slot, triangular cam. This picture does not show the pin and slot on the ball but shows the difference in the cams. Your faucet should have the hole for the pin even if it came with a knob style handle, the pin just presses in. Use waterproof plumber's grease on all these parts when re-installing, and on the threaded cap too.

These parts are usually pretty easy to get at a good plumbing supply store or hardware store in the U.S. Please shop at your local mom and pop store whenever possible, and buy American made products when you can.