Hi

My 76 Sport Spider steering feels loose when I am driving; but seems fine when I jack up the front wheels and check it out. It has 1 1/2" of play with the wheels on the ground; but when I put the wheels in the air; I can steer lock to lock with ease and only have 1/2" of play. I looked at the steering underneath the car with someone working the wheel; but couldn't see anything loose. Any ideas? I tried pulling on the tires to check my ball joints; but they seem fine - no movement. My tie rod end rubbers show some wear (cracked); but I can't see any play in them. Thanks!

Did you check and adjust the locknut on the steering box? That would explain it

My 81 is loose as well. I thought there was some sort of adjustment protocol? I know mine was low on oil, filling that helped a little, but I can still turn my wheel to two o'clock without the wheels moving.

I've had a couple of steering boxes go bad. They begin by excess play in the center position only. As the wear gets worse, it develops a hitch has you turn from the center position. Even with the center play adjustment screw, it can only compensate for so much wear. If you are getting lots of steering play while in a corner, then your issues are loose ball joints or tie rod joints.

There is an adjustment of sorts to take SOME of the play out of the steering.
On top of the steering box is a 17 mm nut, loosen that and then 1/4 turn at a time screw the stem in. There is only so much travel on the stem so go little bit at a time. Might have to get a trunk monkey to help, bit of a pain when all the brake stuff sits above the steering box.
How is the wear on the front tires?
If the steering box does not do the trick, as mentioned better have a look at the tie rod ends and push/ pull the front tires when they are off the ground and check for movement (shouldn't be any)

Does anyone rebuild the steering boxes ???

Just a quick reminder. The Steering Gear "Play" adjustment should ONLY be made wheels straight! Never try to adjust when the wheels are turned. With Weight On Wheels (WOW - Aircraft term) loosen the locknut as stated in the post above, then turn in the center adjustment screw 1/8 to 1/4 turn at a time till you notice all play removed. Then I typically back it out about 1/8 turn. You want to make sure you are not putting unnecessary friction on these gears.
Drive the car and adjust again if needed.
If you still have play, jack up the front end and have a friend (trunk monkey) shake the front wheel from the 9 o'clock and 3 o'clock position. You should be able to spot any loose or worn suspension parts. Make sure you inspect your upper and lower A-arms bushings. There are two in each A-Arm, the rubber can crack and fall out but from one side it will appear fine. 8 total installed on the front suspension.