Borgli

I am really strugling with reading my trannys dipstick.
I checked it when cold - over the full mark, almost at the top hole
I checked it when hot - not even close to full.

I added enough fluid to bring the hot level up to right under the full mark, thinking the full level is more important than cold

Hamster

The AW4 fluid level should be checked with the engine at full operating temperature, running and the gear selector in either park or neutral.

cruiser54

What's the fluid condition if I may ask?

BotakBeng

^this.

Borgli

Fluid is good. I am planing to drop the pan and replacing the filter this summer. I just want to be sure im reading the thing right and prioriticing the hot level.

cruiser54

It's not really a filter but a screen. I've never changed one on an AW4. I was gonna suggest you drain the pan, replace the drain plug washer and add 3.75 quarts of Dexron and you'd know you're fine.

Borgli

Yeah, i know. But I'm dropping the oil pan to replace rear main seal and oil pump, so I thought I might as well change it. I am going to paint both pans red while I'm at it. I was going to do a flush, but atf is so expensive in Norway. Just a drain and fill costs almost 200$!!!

cruiser54

Gotcha. 100% sure it's the rear main or are you just doing it because of the oil pump replacement?

Delta

Changing the filter is nothing but a 35 min job taking it slow once you drop the pan it's one bolt(or two its been a while) and its cheap enough to be worth it

Borgli

I've had a lot of oil coming from somewhere so I am changing the rear main seal, distributor gasket, oil filter adapter gasket, valve cover gasket and oil pan gasket. Hope that fixes it. As far as I know none of them have ever been changed and the engine is from 1990. I was thinking about doing the head gasket, but I read somewhere that if that gasket fails oil leaks into the cylinder and not onto the block? Is that correct?

Radi

Head gaskets might seep a little oil externally, but it would be unusual for one to leak oil into the cylinder without also finding coolant in the cylinder. Or oil in the coolant and vice-versa. 4.0 is not hard on head gaskets like certain other engines are. I'm iffy on changing them unless you need to.

Cherokee89

Borgli, my brothers -88 MJ had an bad oil leak, about one liter in 200 kms. All the experts said it was the rear main seal that needed to be replaced. I told him to come to my place and I fix it for him.
I replaced the valve cover gasket with a new one.
After 2 months and about 4000 kms no oil leak and use no oil at all.
By the way it have gone over 330000 kms now with years of no service before my brother bought it. So always check for other oil leaks first, like valve cover gasket, oil filter adapter o-rings or oil pressure sender.

Radi

Everything in a 4.0 looks like a leaky rear main, lol. Seriously. Oil flows down and towards the back. Often as not it's something else.

cruiser54

I agree with Radi. My standard answer to possible RMS leaks:

I'd be looking up above first, and VERIFYING the source of the oil leak yourself. Many mechanics and friends love to tell you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it? A simple leak at the back of the valve cover could produce the same symptoms. Don't jump on the RMS/oil pan gasket bandwagon just yet.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.
First off, the engine sits nose-up and oil will run back to that area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.
Revised 5-19-2012

Borgli

I have changed the valve cover gasket, didn't help.. I have decided to to "all" the gaskets just because it has almost 300 000km on it.