Drive Line Noise

[HadtobuyaPajero]

Hi All,

Looking for some expert opinion. Hope I can explain the problem well enough...

I own a NW GLX Manual.

I am hearing/feeling a bit of a thud when applying throttle after coasting, particularly on the highway in 4th or 5th. If I am real gentle coming back on the throttle it doesn't happen.

Engine mount maybe?

No other drivetrain noise to speak of. Idle ain't the smoothest but I haven't owned a diesel before so not sure what is normal. Also a little bit of shuddering when changing down at clutch pick up point going into corner etc.

[DAVELOSE]

If the same thing happens to me when I change gears from how many to fifth, the transmission hits me like a bump, but if I let go slowly the clutch does not hit that, what could it be?

[erad]

For what it is worth, I have a NW manual, and occasionally get the thud. I notice it most when I am towing my caravan. I had the engine mounts replaced under warranty because the gear lever thrashed around wildly when shutting the engine down. That cured the shaking but it is coming back again now.

The thud was mentioned to the local dealer and I suggested that it was the rear diff mounts. They supposedly checked them and said that the thud was the towbar tongue loose in its socket. I doubt it, especially when the ball load of the van is far more than I can lift by myself. Whatever, the thud is still there and I think there is a general increase in road noise, but the beast still goes. I will replace the diff mounts some time in the future, but no urgency.

[ozdoogie]

Hi folks, Experiening the same sort of thing with my 2010 NT Manual. 203K on the clock.

Clicking noise from drivetrain , took it to mechanic and they thought rear diff bushes. Diff bushes a ok. Mechanics diagnosed tailshaft is problem - "intenal collapse". $2750 for a new tailshaft from MM.

Got a second opinion from driveshaft/tailshaft specialist. The problem is the tailshafts on the Pajeros have a CV joint arrangement on each end instead of the old unversal joints. these joints "flog (wear) out".

Quoted $550 for each joint replaced and fitted, so $1100 for the job. (Qld- March 2020) The guy was really good and said that my rubber boots on the joints are intact, and most people just "turn the stereo up a bit" to cover the noise.

My experience is almost exactly the same as this OP's experience in the Gen 3 NM-NP group https://www2.pajeroclub.com.au/forum/showthread.php?t=23038

Hope this helps.

Guy

[DibbyDibbyDJ]

Sounds like loose rear driveshaft nuts to me. Remove rear wheels, and centre grease cap. Loosen nut, Spray the hell out of the splines with wd 40, move the shaft in and out as far as you can9only a few mm) and keep spraying. When it moves freely refit nut and tighten (sorry, cant recall torque figure). Refit grease cap and wheel

[PhilipK5]

Check your wheel HUB NUTS. They use a 36mm socket. The local dealer replaced my drive shaft under warranty (thanks) but clunk still present. Another mechanic said diff mount bushes needed replacement (dealer said they were OK) I asked dealer to check hub nuts. Yes we have checked. I then purchased a socket and checked myself. Both sides were almost a 1/4 turn loose. Did up very tight with a torque wrench and guess what CLUNK is now GONE! Yippee

[HadtobuyaPajero]

Thanks for all the replies.

I've tightened the driveshaft nuts and I think it's better[emoji106]. Yet to try on the Freeway but fingers crossed!

[Hatto]

The 36mm drive shaft nut tightening torque is +-240nM if my memory serves me well. So if you dont have a torque wrench, that's BLOODY TIGHT!

[SpanishForWhat?]

The 36mm drive shaft nut tightening torque is +-240nM if my memory serves me well. So if you dont have a torque wrench, that's BLOODY TIGHT!

+-240Nm? That's a massive tolerance!

220Nm +/-10Nm as per service manual.

Not that the damn things seem to stay tight for more than 1000km. I've tried tightening to 300Nm and still no good.

I'm fairly convinced at this stage the nuts are made of too hard a grade of steel meaning they don't deform once torqued and thus hold tight.
If they deformed once torqued, it would explain why the service manual says they're a single use item.
I've tried replacing with new ones, no change. They still come loose fairly quickly.
Bloody annoying that I can't just put my foot down without shuddering every time it clunks.

[old Jack]

This problem has had me wondering for a while so I thought I would compare the Gen 3 to the Gen 4 procedure in the service manuals to see if there was a difference, sure enough there is a difference! Why? I do not know?

Gen 3, there is a spring disc washer between the nut and the hub, the hub torque is 255+/-29NM and if the split pin hole does not line up then you can tighten the nut to 284Nm.

http://www.pajero4x4.ru/piii/GR00001400-27.pdf#page18

Gen 4, there is no spring disc washer between the nut and the hub, the hub torque is 220+/-10Nm and you can either tighten or loosen the nut by up to a 3rd of the split pin hole diameter to align the nut with the split pin hole.

http://www.pajero4x4.ru/piii/GR00001400-27.pdf#page18

Neither of the manuals stipulate whether the torque is a dry torque or a wet torque, usually when a fastners is torque to a high level, both faces of the washer and the threads are lightly lubricated. I am not saying this should be done but the surface friction between the nut and hub on a Gen 4 could be higher than that on a Gen 3 between the hub, washer and nut combination yet the torque figure is 14% lower!
Is there a difference between the hubs, bearings, axles and nuts between the Gen 3 and Gen 4?

OJ.

[Miner]

Good insight. [emoji41][emoji482]


Sent from my iPhone using Tapatalk