The back of the front seat has a play in it. It moves back and forth a little when somebody seats in it. Or even if I try to move the back by hand. (So, not a lot of pressure is needed to apply to move it.) Probably couple of inches back and forth. Which is very annoying.

Did anybody else have this problem? Is there a way to fix it? Maybe there is way to tighten something?

 

I had a similar problem with my xk-8. The seat back is attached with a bolt/pin on each side at the bottom. On my the pin had wore and replacing it solved the problem. I was fortunate that the pin was softer than the steel arm. If you find the arm worn oval you will have to put a sleeve/bushing in it. Give that a look and let us know what you find.

 

Hmm, I'm not sure how that could happen. The seat bolts in with 4 bolts on each end. Did you check that those were tight? I could certainly see it working itself loose over age. Be careful if you decide to take it out to inspect it, it can be a PITA to get back in with the stupid nuts that it threads into

 

I fixed it, and it was very easy.

Once I removed the lever, the covers came off easily.

Then one can see that the back appears to be attached to the seat through a black metal bracket and two 7/16 bolts. (See the picture below.) The bolt closer to the middle (looks like it is rusty in the picture) developed a significant play and that was the source of the movement.

I tightened the bolts (all bolts), and the problem was fixed!