258 cam walk

[frank]

Hi guys, this is probably a common issue, but I can't seem to find much info searching.
I just did the timing chain and sprockets in my '85 CJ, which has about 195000 miles on it. (314000 km, since I'm in Canada)

I've been trying to figure out how the thrust on the cam is controlled.

Near as I can figure oil pressure from the front cam bearing holds the cam forward against the spring loaded button in the centre of the cam sprocket bolt. Oil bleeds off through the small hole to prevent there being too much forward pressure, and to lube the chain and cam sprocket. This should hold the distributor drive gear at zero lash.
Do I have that right?

The reason I ask the question is that the numbers/letters on the head of the cam bolt are just barely starting to touch the front cover, so I assume that either the button has worn down, the spring has gotten weak, or the distributor bushings are getting too worn.
Am I on the right track?

[jeepsr4ever]

Your cam will walk in a 258 after many miles. After you see more than .0065" of wear on the lobe you will get walking back and forth of the camshaft. The lifters actually hold the cam in.

[frank]

Ah, I see. What is the function of the spring loaded button then?

Guess we'll see how long it keeps going. It's the only engine I've ever owned that used virtually no oil, (just below the full mark when it's due for a change) never mind with those kind of miles on it.
Maybe I'll pull it down and overhaul it in another 100000 or so.