I went down the coast yesterday and noticed at highway speeds a noise that I am quite concerned about.
At 120 full load no noise, no throttle no noise either, but as I just touch the throttle or just as my foot is about to come off the pedal it is making a grinding rumble sound felt and heard through the whole car. If you toy with the throttle you can gt it to do the noise for a while if you get the throttle right but it is only like 2% throttle
It does it in 4th or 5th gear. I have tried 2 tailshafts and its the same with both. I am finding it hard to tell if it is coming from the rear diff or the gearbox or transfer, but I am thinking it is the diff.
Driving round town here it seems fine. It seems to only happen at highway speeds over 100kmh and the faster you go the worse the noise.
Has anyone ever had this or have any ideas where to start looking or how to diagnose this?????????

Cheers
Dan

geeze mate you are having a crap run of luck with the truck, sorry I can not help any further

 

geeze mate you are having a crap run of luck with the truck, sorry I can not help any further

GOT A MATCH?????????????????????
I AM REALLY CONSIDERING JUST GETTING RID OF IT. I THINK THIS ALSO MAY HAVE SOMETHING TO DO WITH THE VIBRATION ISSUE, OR WAS CAUSED BY IT. ITS A PITA.

 

I once had a hilux with a similar noise to what you are describing (although the hilux would be absolutely flat biscuit at 120). It was the pinion support bearing which them stuffed the crown wheen and pinion gears in a short space of time. The noise travels up the tailshaft and sometimes sounds like it comes from the gearbox etc. If you haven't already check the play in the rear dif and check the pinion for play. If anything else you will be able to rule it out if it is OK.

 

Thanks for the reply red. How do I check for play? Is it up and down movement I am looking for or excessive play when rotating the tailshaft???
It does sometime sound like it is coming from the diff, but then it sounds like the gearbox, its hard to tell. Someone also sugested the clutch, but it only does it at high road speed, not high engine speed, so the clutch I think can be ruled out also?

 

Could it be the flywheel? I think I read somewhere that the 2.8 has a similar (dual mass) flywheel as the 3 litre jobbie and they can set-up those sorts of symptoms when they go wrong........

 

Mr Nismo.

Is it a whining noise or a vibration noise?

If it is a vibration noise then it is either the tailshaft universal joints or the slip yoke has excessive wear.

Vibration while underload (say from 85 to 110kph) is a general indicator when either the uinversal joints or slip yoke is worn or has insufficient grease.

Grease the slip yoke and universal joints (do not over grease the universal joints. Excessive grease will pop the seals and alow water & dirt into the universal joints) then do a test run at the above speeds. If the noise is gone then all is good.

Slip yoke wear can be identified by trying to rotate the tailshaft in a clockwise to counter clockwise direction or pushing up & down on the slipyoke. If you see movement in the slip yoke when turning the tail shaft then it is slip yoke wear causing the vibration noise. If the tailshaft has movement up & down in the slip yoke, then it will cause a vibration at the above suggested speeds.

If it is a whining noise then drop the oil from the diff & if there is metal shavings from either the hemisphere bearings or pinion bearings. Get the diff looked at sraight away as you could damage the gear set.

Effect of of incorrect pionion preload.
Incorrect pinion pre load causing noise. When you "accelerate" the pinion moves or pushes into the carrier but when you back off the throttle or "coasting" the pinion pushes out of the carrier, thus giving a "whining sound". This can be caused by incorrect pre load of the pinion bearings or "hard accelerating then backing off" (mainly with a heavily laiden vehicle).

Effect of incorrect backlash.
Incorrect backlash will give you a "clunking noise". This is evident when you are accelerating then "back off or coasting". Excessive backlash in the differential is also not good for the gearset due to the "incorrect contact position" when under load or when coasting (contact moving from "toe to heel positions" when under load.( Also if you have incorrect backlash within the gearset then it will quickly alter the pinion preload & cause failure to the gearset.

If it is not the above then it is either transfer or gearbox. If it is the gearbox then also drain the oil & check for metal shavings, this is a quick indicator of bearing failure or a damaged cluster gear & associated gears within the box.

Sorry for the long post, but hope this helps.

 

Sounds like pinion bearings albeit if youre gong to have the diff pulled apart you would have the carrier bearings done as well, this would then rule out the diff

 

Roachie, I have thrown the dual mass in the bin, and is now a solid unit.

Paul.helm the tailshaft has been fully checked and checked and checked again, new unis, balanced by a driveshaft specialist. I also have another spare shaft, and it does the same thing with both, so I have pretty much ruled this out.

Its isnt really a "whine" or a "clunk" more of a rumble, or grinding sound like a dog growling.
Its so hard to tell where it is coming from. And as I said before it is only when you feather the throttle, under load it is smooth and quiet and also when coasting it is also smooth and quiet.

 

Jack It Up And Put On Safty Stands And Run In Top Gear,listen With Screw Driver On Ear ,posible Wheel Bearing Or Diff Bearings...

 

Thanks for the reply red. How do I check for play? Is it up and down movement I am looking for or excessive play when rotating the tailshaft???
It does sometime sound like it is coming from the diff, but then it sounds like the gearbox, its hard to tell. Someone also sugested the clutch, but it only does it at high road speed, not high engine speed, so the clutch I think can be ruled out also?

Check for excessive rotation and also up/down movement. Also as suggested above you could put it up on stands but be VERY careful if it gets a vibration up and comes off the stands you could have a major incident.
Or pull out the axles first then run it up

 

Take a run past Snake racing see what they say.

 

Take a run past Snake racing see what they say.

He wouldnt know his arse from his finger. I am in the process of moving house at the moment, so all my tools are packed and in storage. I am going to try and get to a mates place this week to drop the diff oil and have a look. I think that is what it is. Also I will be taking it to a diff specialist on Monaday. It seems most people seem to think it is a diff bearing problem???

 

take the rear tailshaft out . slip it into 4x4H . u will be driving with front diff only.. soon will tell if its gearbox or rear diff.
vince

 

Sounds like Pinion bearings......

After you dump the oil and if there are no contaminents, pop the axles out & check the axle bearings for excessive movement (up & down, left & right, just like checking preload on the front wheel bearings). This was a problem on my old MWB cruiser, they were worn out and this generated the "grinding noise or growling noise" that you describe above.

If you decide to drive with just the front diff, be cautious as this will cause abnormal wear to your unis etc, especially when turning at speed.

Just some additional information also.
I am not certain if the front crown wheel & rear crown wheel are cut in the same direction. (I have not had the diff centres out of my Patrol so I don't know). The rear crown wheel should be a "righ hand spiral" (from the inside diameter of the gear to outside diameter of the gear) & the front should be a "left hand spiral" (from the inside diameter of the gear to outside diameter of the gear). If this is the case then you would not do any damage to the front gearset if driving on the front diff only.

If the Patrols have a Right hand spiral gear for both front & rear, I would certainly recommend that you don't drive with the front diff only. The reason for this is, this configuration is called a "flipper type differential" and it is not recommended due to the drive loads induced onto the "opposite side of the gear tooth flank".

I am sure that some on the forum members who have removed both diff centres would be able to clarify which direction the gearsets are.

Hope the above information is not too confusing but this is as simple as I can make it from my text books.

Good luck mate...PM or email me if necessary for further clarification on the above.

 

Now bear with me on this as the other half isn't here for me to check with him, but we had a similar noise that would happen at about 100km/h in fifth gear only. Thought it might be the diff as the noise was hard to pinpoint, but in the end it ended up being because we had put a spacer under the gearbox. The noise was travelling down towards the diff, but when we took the spacer out the noise stopped.
Don't know if this is your problem or not, but thought it was worth a mention as there's nothing worse than chasing noises and thinking of all the dollar signs.

 

Helmsy, I think you are right about the pinion bearings. I think I might just wait untill Monday so the diff spcialist can have a look. I dont want to dump the oil as this might hinder his diagnosis.
Ourtruck, thank you for your suggestion, but I have no spacer fitted. I have a mate with a GU with a 7" lift and he said he has the same noise, and described it to me exactly. Mine does it in 4th gear aswell as 5th. Your right about chasing noises, it sucks!!!!!!!!

 

what happened ......? any solution so far? me facing same problem.

 

That's 4 years ago. I'm guessing if he hasn't told us by now he isn't going to. You could try a PM...

 

Gay! I got same thing.

 

Me too

 

Annyone sorted out this noise?