Symmons Temptrol cartridge replacement

I have a temptrol fixture in my stall shower. It has been leaking from the shower head for several years, but a couple of days ago, the washers went completely and the drip became a dribble. I have changed cartridges in the past successfully, but this has been a pain in the rear.

I purchased a new cartridge, but the old bonnet nut did not thread fully onto the new cartridge; the bonnet nut would not meet the pipe threads. So, I purchased a new bonnet nut.

Now the question -- with the new cartridge and the new bonnet nut, are there any other washers/gaskets I need to add to the setup? I've got it all together, but there is still a drip from the faucet (where bonnet nut meets pipe). I just want to make sure my only problem is lack of upper-body strength...

There is thin washer that goes between the bonnet and the valve body. When you purchase a new spindle it doesn't come with it, I don't know if it comes with a bonnet I've never purchased one separately.

That one's there; but thanks for the suggestion!

Ok, then did you tighten the packing nut?

Is the packing nut the same as the bonnet nut? The Home Depot DIY book we have calls the piece that goes over the cartridge the bonnet nut. The name makes sense; it is kind of bonnet-shaped.

Of course, the problem has gotten larger. I decided to just let the faucet drip while I took a shower this morning and the water pressure is almost gone. There is a way on this faucet to prevent scalding and no instructions on how to adjust it; could this be part of the pressure problem?

Let's go with Symmons terminology. The cap (bonnet?) has a smaller nut on it that surrounds the spindle (stem) which is called the packing nut. If this is loose it will leak when the faucet is on. The temp setting is a small screw head also on the cap (face).

Thanks, Plumguy. I started thinking about your question after my impulsive answer and then went to check my hardware. I ended up tightening the packing nut per your instructions.