Preventative maintenance - high mileage

What are your opinions on parts to change out for preventative maintenance on high mileage Cherokees? I am looking to get ahead of things that might be normal failures for Xj's.

Is it new to you? If new and the age/condition of fluids is unknown, I'd suggest going through it thoroughly and changing fluids that are suspect.

If you've owned it for a while, then you know the condition of fluids and (hopefully) have kept up with regular preventative maintenance.

Otherwise, I'm not sure I would just go through and swap parts as preventative maintenance.

X2. Change all fluids including brake and power steering. Other than that, if it ain't broke, don't break it. The part you take off might be better quality than the one you put on.

the term "high mileage" is subjective. please give actuals. I consider 400K sort of high, and 200K about average , not high.

All fluids. all of them.
consider the CPS, TPS, and carry your current "working" ones as spares.
plugs, cap, rotor, o2 sensor, plug wires, clean grounds, change all fluids.

take a good look at the harmonic balancer.
trackbar mount and trackbar tighten down.
brakes and flush/bleed brakes.
ball joints/hubs

check compression

radiator, upper and lower hose, thermostat, spring in lower hose
water pump


high pressure power steering line

alternator

motor mounts

exhaust manifold(if cracked)

Skwirl said:

What are your opinions on parts to change out for preventative maintenance on high mileage Cherokees? I am looking to get ahead of things that might be normal failures for Xj's.

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Year?
Present Mileage?

Excellent start, thx......

Just getting familiarized with Xj's. Didn't know if they had any common problems that I should be worried about.

Already done the ignition (plugs,wires,rotor & cap), fluids and filters etc.

I will move on to TPS,CPS, O2 sensors,hoses & belts now.

Jeep is a 99 with 145k....not really high mileage for a 4.0 but its got some years

Got an extensive build sheet planned for this one in the near future.

Skwirl said:

Jeep is a 99 with 145k...

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Pfft..... You gotta fresh one there. Might be due for a wash, maybe a wax by now

Skwirl said:

Excellent start, thx......

Just getting familiarized with Xj's. Didn't know if they had any common problems that I should be worried about.

Already done the ignition (plugs,wires,rotor & cap), fluids and filters etc.

I will move on to TPS,CPS, O2 sensors,hoses & belts now.

Jeep is a 99 with 145k....not really high mileage for a 4.0 but its got some years

Got an extensive build sheet planned for this one in the near future.

Click to expand...

PM is called PM for a reason. Look at the Owners manual, does it say "Replace alternator, starter...", nope. It says "Check and and replace". There is a list of items in the manual. Look at those. OEM Items are pretty serviceable for quite a few miles, and replacing them does not insure against breakdowns.

Look for cracks in the back of the belt. If it's cracked, replace it.
Examine all hoses. Bulges, wear marks, replace. Get good quality clamps or re-use OEM.

Unless you bought a high quality Cap and Rotor, put the old ones back in and carry the new stuff as spares. Nope, not kidding. A Cheap Cap and Rotor will leave you by the side of the road within 10K. Keep a spare cap and rotor in a bag under the rear seat. Plugs should have been Champion or NGK.

Since you replaced the fluids (Good quality 10W30 Engine Oil, Quality Filter, Air Filter, and a refill with Dextron/Mercon for the auto ( Only up to the "Add" mark when cold btw ); If the Jeep is running normally with out throwing codes, take a rag sprayed with carb cleaner and wipe out the throat of the TB, and walk away from the engine/trans. Don't replace anything else unless it is actually bad.

Cooling System: Is the condenser clogged with dirt/debris? What does the radiator look like? Does the clutch fan spin too easy when cold? Does the electric fan run smoothly? If not clean/replace items as needed. These are items which cause cooling problems, one of the most often complained about issues with the XJ, so check them.

Go next to the normal wear items in the suspension. Check the ball joints, Tie Rod Ends, and U-Joints. Check the wheel joints and front wheel bearings.

Remove the rear drive shaft and grease the slip joint at the transfer case.
This is also a good time to examine the u-joints in the rear shaft.
The front shaft often has a problem with the ball seal in the CV joint cracking. You need to tear the CV joint apart in order to re-grease the ball and replace it, so you might just as well wait until it makes angry bird sounds or you decide to replace all the joints in the shaft.

Check the brakes, look for divots in the front caliper brackets on the knuckle. Build up divots with a welder and file back flat, then replace the shoes.
Check the rear shoes and hardware. Self adjusting cables break. Hardware rusts. Often times the rear adjuster doesn't do a very good job of self adjusting, so after checking/replacing rear shoes & hardware, put the rear together, and with the rear on stands and adjust them by hand. It will make a difference.

-Ron

I just wanted to x100 on the crankshaft position sensor. My best friend gave me some excellent advice that I took to heart. Always have a CPS in the glove box and the long extension+socket wrench underneath the seat. If anything will leave you stuck, it is that. It has saved me three times now. In fact, I always keep the known good one in reserve.