Replace timing chain on 99 jeep 4.0

Check your timing points. Use the correct TDC.

are you on pavement, or offroad.?
99 Cherokee what transfer case?
if Part time system. then,.
are your tires on ice or dirt?
if not its cockpit error.
read the operators guide, on this.
if on ICE,say so, we can not know what transfer case you have
nor what tires are sitting on.
do tell, and we can tell you what good or bad.

here is the build list for these years XJ
what do you have. ?
The full time box, must not be in 4Lo , on pavement
unless it too is on ice .

All the transfer cases used on the Cherokee were chain driven with aluminium housings. Command-Trac was standard on XJ models built with 4WD.

• 1984-1987: New Process NP207 Command-Trac, part-time only, 2.61:1 ratio with low range
• 1984-1986: New Process NP228/229 Selec-Trac, full- or part-time, 2.61:1 ratio with low range

NP228/229 has a vacuum switch for 2WD-4WD selection on the fly and a separate manual lever for low range

• 1987-2001: New Process NP231 Command-Trac, part-time only, 2.72:1 ratio with low range

NP231 has the following settings: 2HI, 4HI, N, 4LO

• 1987-2001: New Process NP242 Selec-Trac, full-time or part-time, 2.72:1 ratio with low range

NP242 has the following settings: 2HI, 4 full-time, 4 part-time, N, 4LO

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never post questions on 4wd unless you know what is there.
the transfer case, also has tag , telling what it is.

alldata.com log in read.?

You have a timing chain that is good for the life of the engine. The only thing that could need replacing is the chain tensioner if it starts to make noise.

Have all the parts been replaced including the timing chain? If not you must do that first.

Hi there;
Just rotate the crankshaft so that the timing marks are aligned...





FIG : Timing chain alignment marks - 2.5L and 4.0L engines



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You change the timing chain now when your Jeep has indicated from a check engine light on. The timing chain in engines these days last as long as the engine will, there is a timing chain tensioner to ensure there is no slack.
When the timing chain has gotten stretched to much, your Jeeps PCM will indicate that with a check engine light on your dash and will be indicated with a DTC codes from a scanner.
So no worries about replacing your timing chain and keep up the regular maintenance, if you have a Mechanic tell you other wise, there just looking for money and your looking for more then just a timing chain being replaced.
You can bet that chain, chain tensioner, timing gears, water pump and might even throw in a cam replacement will be in his recommendation.
Thank you for using fixya and be safe.

get a haynes manual at a discount place or search online

You will not need to change a timing chain unless you know or suspect it to be bad. Belts and other material that wear down need to be changed but the timing chain itself is a metal similar to that of a bike chain but much shorter and thicker

hi there if you already replaced the timing chain then you must have aligned the crankshaft mark to the mark that is on the cam sprocket ?