Oil pan removal/install on 4.0 questions

[BigClay]

So how hard is it to remove an oil pan on a 98 4.0 and replace it? Got any tips or tricks? I smashed my OE one and now the drain plug is pointing upwards, so what would be the harm in drilling a hole in the damaged pan to drain the oil? Any comments or suggestions welcome!

 

[grapehead]

bunch of bolts, easy. electric impact makes it go quicker. drilling the hole sounds like a good way to not get covered in oil when you drop it! how many miles on the motor? might wanna do the rear main seal while you have it off, and/or timing chain...

 

[flatblackzj]

i'm not for sure on a tj, on the zj's, wj's, & xj's i've done, jack it up & support it on jackstands to allow the front end to fully droop for clearance to drop the pan. i'd recommend changing the timing chain while you're there, possibly the oil pump as well. melling makes a good high volume replacement pump with a cast iron body-i'm not a big fan of the factory aluminum body pumps.

 

[BigClay]

Thanks guys. It has over 200k on the motor so a rear main seal is probably a good idea.

 

[shawn]

Mine is not stock, so I can't comment on track bar clearance or anything like that. But mine is lifted 2.5 inches, and it pretty much fell off. Bunch of bolts, then a little prying because the pan got hung up on the dust shield at the front of the bell housing. I didn't even change the gasket. Did the pan and the motor mounts in the dark in about an hour's time, talking on the phone for part of that.

 

[shawn]

Don't bother with the timing chain. Whole front of the motor has to come off, but the oil pan does not.

 

[flatblackzj]

definitely check timing chain stretch while you're in there, the later 4.0's i've been into lately(especially w/high mileage) have had a bad habit of showing excessive stretch (over 1/2" slack), this can give erratic cam sensor phasing faults & check engine lights

 

[Jody Treadway]

Did the pan and the motor mounts in the dark in about an hour's time, talking on the phone to Jody debating on replacing the gasket or not for part of that.

Fixed it for ya!

@BigClay : The pan will come right off without any issues on a lifted TJ. As long as the oil pan gasket sticks to the block (like 99% of them do) then just swap pans. Put a small bead of engine RTV in the corners of the pan to aid in sealing.

If you do replace the rear main, it is important to run a small bead of the proper RVT along the sealing surface of the rear bearing cap. Go ahead and install a new oil pump while you're in there too. You're only 2 bolts away from doing so.

 

[shawn]

Nah, I think I called to ask if you'd bother with RTV at the corners of the pan where it turns down over the main caps. I put a thin film on both. No leaks.

In unrelated news, I put too little RTV on the SUA SYE tailhousing swap, and a post-installation extra layer didn't stem the tide. I'll probably have to pull that one back off. It's leaking around the shift rail.