Routine maintenance for Jeep with unknown history

[sa1126]

I changed my oil and air filter but am wondering what other fluids need changing.

Which of the following do you think are crucial? I do not have any service history whatsoever.

1. Differentials
2. Transfer case
3. Radiator
4. Transmission fluid
5. Brake bleed
6. Clutch fluid
7. Power steering fluid

Anything else I am missing? I am thinking of doing the diffs and coolant for sure since my rear diff cover is oily.

 

[06lj]

Brakes are always number one. It's not life threatening if your Jeep won't start or overheats. No or poor brake performance can end badly.
After that all new fluids is a good idea. Also check bushings and bearings for wear.

 

[sa1126]

Brakes are definitely on my to do list. They work well but I have not inspected them closely to see how much life is left on the pads or wear on the rotor. I vaguely remember my mechanic friend saying cars don't really need to be bled very often but I used to do it on my motorcycle every year or so.

I am guessing they have never been bled so the fluid is about 17 years old :/

 

[Chris]

Change all of it, especially if you have no knowledge of when it was last done. That way you know everything needs to be done again in X amount of miles.

Also change the O2 sensors, spark plugs, and doing a cooling system overhaul.

These threads will come in handy:

Jeep Wrangler TJ Cooling System Overhaul FAQ
The Official Jeep Wrangler TJ Oxygen (O2) Sensor Thread
What are the best spark plugs for my Jeep Wrangler TJ 4.0?

 

[toximus]

I agree with Chris, change everything. For bonus points, take samples and send them off for analysis to a place like Blackstone Labs.

 

[Gollywomper]

Agree as well. I changed all my fluids, except coolant and brake fluid when I bought my TJ. The coolant was bright green and looked good when I checked it when buying. Within 6 months it turned dark and rusty. Flushed the system and had been perfect for over a year, so don’t over look coolant.
I just recently flushed my brake fluid, that did make a bit of difference in pedal firmness. Could have been some air build up it regardless it is a bit better after changing.
Next would be tune up and O2 sensors.
Also check and torque all suspension mounting hardware. It never really ends.

 

[Flivver250]

The satisfaction of good maintenance is half the fun of owning a Jeep. Do it all. +2 on the brakes. I enjoyed a significant improvement in braking when I replaced the entire system. I'm a big fan of stopping on a dime with 9¢ change. Preventive maintenance is significantly less expensive than reactive repairs.

 

[KCsTJ]

Keep a chronological maintenance and repair log. Comes in handy so u don't have to remember everything

 

[AndyG]

Keep a chronological maintenance and repair log. Comes in handy so u don't have to remember everything

Kc , of whom my lights are named after I think, always has some solid common sense advice .

Of all fluids , brake fluid goes bad even if not used ..,absorbs moisture .


Looks like a nice Sahara in the avatar.

 

[Kiwi TJ]

'Do it once and do it right' as my Dad says...change all the fluids, plugs and filters. Then you start with a clean slate.
Plus you can spot any current or up and coming issues in virtually every area of you Jeep.
Cooling system is where I started with mine as they seem to go fairly early on....replaced the Radiator, Pump, Thermostat and hoses.

 

[Flivver250]

'Do it once and do it right' as my Dad says...change all the fluids, plugs and filters. Then you start with a clean slate.
Plus you can spot any current or up and coming issues in virtually every area of you Jeep.
Cooling system is where I started with mine as they seem to go fairly early on....replaced the Radiator, Pump, Thermostat and hoses.

Replace the fan clutch, idler pulley and belt tensioner as well. The one part you omit will always always always be the single point of immediate failure. Aw hell, replace the temperature sending unit as well and flush the system repeatedly. When I flushed mine I found Jimmy Hoffa in there.

 

[sa1126]

Thanks all. Heading to walmart on lunch break with a hefty list. Need to find my old mityvac but I will probably start on the differentials this weekend once I can get to harbor freight to grab some plastic scrapers.

My factory build sheet mentioned "Command-Trac Part Time 4WD System". Does that mean I need to grab the limited slip additive? Will I need it for both rear and front?