Your breakin me heart mate....salt mines have me for a few more hours...coldies and some cricket would nice on a warm West Coast SA arvo...just have to settle for the radio coverage of the cricket

Farwest, mines the early diesel like yours, last oil change I went for the 7 litre bottle as I am getting a collection of 10 litre bottles with a bit left in them sitting around, I usually buy whatever is on special at the time, mine took the 7 litres and a tad more got it bang on the full mark on the dipstick., I have overfilled it before while measuring out the 8 litres.

Ours also have a different sump plug to the later models, it's quite a bit larger. I couldn't buy one locally (bought 2 and they were both too small) had to measure it and grab a generic one online.

From memory it was 14.1 mm or thereabouts.

After much time the oil change was finally done.....7.8lts put the Oil Level smack on the MAX mark in mine.
Thats an Oil and Filter change...run engine...let oil settle for 10 minutes...dip...oil smack on MAX.
40Klm round trip to ensure oil was circulated and engine at operating temp...let oil settle for 10 mins...dip...oil smack on MAX
'13 Model 5 speed Diesel.


Dip method....remove dipstick and wipe off....leave dipstick in tube but with around 15-20cm hanging out the top...allow oil to settle(10-15min) then insert dipstick fully, leave inserted for 5ish seconds and withdraw....no 'wicking ' up tube using this method.

2012 GC Overland diesel in NZ ,always had eight litres put in it since I have owned it,never a problem.Been using Penrite 5w40 Enviro will change to the 10w40 Enviro when next change is due.Also put in half a bottle of Penrite zinc additive ! The independant Jeep guy in NZ I know has been putting it in his two GC diesels for three years ,no problems yet ..he has Rebuilt a couple of VMs,said the width of the main bearing shells was very narrow and the main bearing locating tabs were nearly non existant.He said very little difference in VM motors
from 2012 to 2018.He has fitted a early motor into 2018 with no problems.

Off topic a tad, but I 100% believe the problems with the bottom ends in the VM is the very small bearing width...imo. When designing this engine in conjunction with GM initially, one of the design criteria was to allow the engine to be mounted transverse in the front of any vehicle as well as longitudinally. The engine block was designed very compact.
Hence the importance too of regular oil changes to keep the oil condition tip top.
The bearings' surfaces were increased it appears by increasing the journal diameter...not the width....so given the torque available the bearings will take a hammering over a very small area, and often will break through the oil film and grab the bearing shell...bang goes you engine.

Sound enough theory Jeeper6.
On that basis an upgrade to a thicker viscosity oil and an additive really cant hurt, and, the factory went that way.(with the viscosity)
Bjm mentioned a Zinc additive....I use Moreys.
Oil used now is a 10w instead of a 5w.
No Moreys added at this oil change but a 'residual' amount remains on 'coated' surfaces. Only a miniscule amount, but, its there.
Bit like the old days of adding Slick 50 to the crank case, diffs, gearbox, transfer case.
Treatment was added once, not at every oil change.
I understand the thinking that all additives are 'snake oil'....however....there have been times when bits n pieces just lasted longer and showed zero signs of wear after long time frames of HARD use.
Maybe a placebo, maybe not.

Agree with both the above but also the often overlooked item is the filter, in many engines the oil is really okay but the filter is what has reached its limit... in the days of real 4x4's mods were done to fit larger oil filters when you look at lots of these modern donks the filter area has shrunk, the improvement in filter medium hasn't improved all that much and I suspect done to fit a certain area and budget...
When travelling if I hit the 10K km I will change the filter and let the oil run a bit longer.... With years of DiYing and hearing various vehicle dramas I have come to the conclusion that the servicing quality has a lot to do with things as well..... Looked around a Jeep workshop once and didn't see any oil grade that mine was supposed to have, the apprentice told me we just use that Castrol in it, wasn't the one for my OM612 engine at all.....