Preventative Maintenance Suggestions

[NYC-TJU]

Hi all,

Wanted to know what type of special preventative maintenance is important for these old 4.0s. Mine currently is sitting at about 225K miles, runs great, and averages about 15 mpg. I have the normal exhaust leak under the hood that disappears once warmed up, and other than that all seems good.

I do regular oil changes, & plugs/wires/injectors have all been updated. Other that that, anything to consider with this high of mileage? I've heard these old 4.0s are (almost) indestructible, so want to make sure I'm treating mine right!

Appreciate any jeep-veteran insights!

 

[Ante_Up]

Unless you know exactly when they were changed, you could consider changing fluid in the differentials, transmission and transfer case. You could do a cooling system flush, brake fluid flush... Just your typical PM for any vehicle

 

[NYC-TJU]

Unless you know exactly when they were changed, you could consider changing fluid in the differentials, transmission and transfer case. You could do a cooling system flush, brake fluid flush... Just your typical PM for any vehicle

Good point - forgot to mention those. I just took it on a 400 mile trip, so beforehand i changed both difs, transfer case, and the transmission fluid (no idea when they were all done last). The cooling system should be done next, but I can smell a heater core leak so want to get to that first. Definitely not looking forward to that - seems like a major PITA to do.

 

[Ante_Up]

Good point - forgot to mention those. I just took it on a 400 mile trip, so beforehand i changed both difs, transfer case, and the transmission fluid (no idea when they were all done last). The cooling system should be done next, but I can smell a heater core leak so want to get to that first. Definitely not looking forward to that - seems like a major PITA to do.

Yep, that's word on the street. I haven't had to tackle a heater core yet!