chains
1998, 318 is fitted with a timing chain not a timing belt.
If it's a M43 engine it has a chain.
do you have to change a timing belt on a 93 318 is BMW
Worn timing chain.
There is no recommended replacement interval given for the chain replacement timing belts are critical, chains are not.
TDC is top dead center it pretains to the position of the pistons. The number one piston has to be TDC when you put on the timing chain or belt for it to work properly.
Valve timing is not adjustable on a stock engine. The timing chain is either installer correctly or not.
1/4 MAX
It is set to zero degrees with a scan tool. It can not be done with a timing light.
60 to 100k depending on service
That is the timing chain cover.
Since you mentioned that your Jeep is has the 318 (5.2L) engine I'm thinking that you are wondering about the timing chain? If you go to Google and type in "Dodge 318 timing chain" you 'll find a world of good sites including ones with step by step directions with pictures detailing how to change a timing chain on this engine. If you're talking about chains for the tires.....ummmm.......why would anyone need chains for the tires? If the snow is that deep maybe what you need is a SnoCat. If its not the timing chain then you need to provide a more detailed question for us to ponder. Brevity is nice but clarity is better. Good luck !!!