[klappers]

Check the rear tail shaft slip joint first. Grease it up and check if noise is still there

 

[klappers]

Cheers @klappers.

Bit of an update though. The transmission guy took it for a drive. says it is not the gearbox, and that the knock is frontend related.

So gonna replace radius bushes (ones got a split, but we kinda doubt a little split could make such a large knock). Reseat Springs (I'll add that if I take off slowly the knock sounds more like rubbing/loading up noise). And yeah we'll check that slip joint first.

Must say, the auto trans is getting a little slow so still don't think I'm out of the woods on this one. But it's going back soon for a service. let the saga continue.

The other thing that can make a big knock in the front is the "mushroom" bushes on the ends of the radius arms at the chassis end. Is this what you were checking or the differential end?

 

[klappers]

We're doing all of them.

Cool. Wouldn't surprise me if you find something loose

 

[klappers]

Bit of an update on this and it's really not good. Starting to loose a bit of love for the old girl.

We replaced radius bushes all 6. It may have settled the loading-up noise. But the significant knock is still there. My mechanics are at a bit of a loss. But his next steps are.

@klappers My guy ruled out slip joints.

The transfer case has been replaced at some point in its life. So we'll drop and inspect the oil on that.
Suss the diff oils.

The engine/trans mounts look pretty good but we're not ruling them out. (It does knock every now and then when its first turned over).

BUT... Here's where it gets interesting and it is probably worth starting another thread.

As soon as I pulled out of the mechanics she started missing and was absolutely gutless. Great, we got engine problems.

Mechaninc rekons coils are gone. But what are the odds, the engine has had zero problems on a recent trip to Melbourne and the past three months? Seems that the list of things going wrong keeps growing.

I don't know when to cut my losses. So if anyone has words of wisdom. I'd be bloody keen to hear it. I just want to get on a track.

You need a laptop and NDSII with an OBDII USB cable.
If you have any problems, you'll be able to find them with this.
What is the mechanic using to diagnose these issues? I feel like they are stabbing in the dark?

Also, how did they diagnose the slip joint?

 

[klappers]

So after I left the car at the shop. The Mechanic did a scan and got the ignition primary code. Which he wants to replace harnesses and coils at once. I took it home and the missing was intermittent, went for a drive in yesterday and it was fine. But the day before was missing every time I hit the accelerator.

Cause it's so intermittent, would it be better if we just did the harness first? MAFs been cleaned. Mechanics are telling me to stay away from after-market coils. Even online seems to say stay away. But all comes down to $$$.

As for the slip joint. We have only diagnosed that because noise is coming from between the trans and the engine. But I might chase it up again.

As for the knock. After replacing the radius arms it seems that half the knock is gone. (The loading up part) But the big clunk is still present. I think the next thing is engine mounts (as you can hear the knock when you start up the engine. just once..). Then trans mounts.

Cool. Well that's some good news about the knock. Sounds like bushings and mounts are a very good place to start.

Coils - I would recommend the Hitachi ones. About 30bucks cheaper then "genuine"... Which are Hitachi

Coil Pack Hitachi Japanese Made for Nissan Patrol GU Y61 TB48 4.8L

Coil Pack Hitachi Japanese Made for Nissan Patrol GU Y61 TB48 4.8L

patrolapart.com.au

Sub harness is 120 bucks.


Sub 1k to redo the ignition circuit isnt bad. I would change your spark plugs while you are there. Make sure you use iridiums

 

[klappers]

Does your 1k estimate take labor into account? Mechanics quoted 1500.

They're charging you 500 bucks to rip out the old coils, unplug the harness and reinstall?

Mate, you can do this all yourself! It's all bolt in and out.
Like I said, grab an inlet manifold gasket and change the spark plugs while you're there. Should be less than 3 hours go to whoa

 

[klappers]

Ahh, more of an update. Pretty sure I've found the culprit of the knock. Feel a bit silly if it is. I'm missing the nut for the left transmission mount and the cross member. Tragic that two mechanics have completely overlooked it.

Gonna replace the whole set. Does anyone have any resources to swap them out? If I jack the box up will they come out?

Should be ok. Still attached at engine

 

[klappers]

@klappers Can you do it without removing the cross member?

I would have thought so, just make sure everything is undone around the gearbox and you should be sweet