Severe clunking noise

[tonkatuff Lurker Find all posts View Profile Close tonkatuff]

99 model Prado v6 3.4l, problem loud clunking noise when under load, i.e letting clutch out in first and second gear. first changed front tail shaft(not problem, still existant) then persisted to change front diff(prob still there) changed front left cv and wheel hub. to my dissappointment problem still there.. in the initial stages I removed the transfer case and opened up and looked like new no where. but now I am bak to thinking it is the transfer case. as the problem is non existant when front tail shaft removed and is ten times worse when just the rear tail shaft is disconnected, as is the problem worse when is in low range gearing.... has anyone experienced this. as there is not much else left to replace...?????? :? :? :? :? :? :?

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

Re: Severe clunking noise

Transfer/transmission mounts?
I've spent many recent evenings trying to locate a clunking noise in my vehicle, and finally found it tonight - a mildly loose panhard bar. I only found this by getting underneath and shaking the crap out of anything I could hold onto. And I dont mean a little shake with one hand - I had to use my full body weight and strength to create the sound. Have you tried this?

[Beast2h Member Find all posts View Profile Close Beast2h]

Re: Severe clunking noise

is it worse when turning?

[williade Avid PP Poster! Find all posts View Profile Close williade]

Re: Severe clunking noise

Front drive chain and or sprocket? Main bearings on the front pinion flange? Its starting to sound expensive what ever it is

Is there any oil leaking from the front drive oil seal in the T-case?

[Derb Senior Member Find all posts View Profile Close Derb]

Re: Severe clunking noise

Holy smoke Boss - stop replacing parts and get a decent mechanic to take a look. Could end up being a cheap fix yet. Been up this road before today with bad vibration and replaced all the driveshaft u-joints and balanced the shafts. Luckily didn't get to the cv stage. Ended up being the rear wheels out of balance. Felt a right plonker. Good luck.

[dhula Member Find all posts View Profile Close dhula]

Re: Severe clunking noise

When it comes to clunk on takeoff/gearchange IMO it's best to start at the easy stuff such as
*Make sure there isn't something rolling around the back of the car causing the noise
*Check to ensure wheel nuts are tight and wheel nut holes are not oval
*Check tightness of all suspension nuts and bolts including the front end
*check tightness of front and rear drive shaft nuts/bolts
*Put a squirt of grease in the UJ's

after that you could likly check
*Freeplay between left/right drive shaft and front hub assy where the shaft goes thru the hub.
*Tightness of the nut that holds the shaft into the hub assy
*backlash in front/rear diff
*back lash in the CV's themselves (long shot)
*backlash in t'case

That should cover the most likely culprits I recon

[Leethal Advanced Member Find all posts View Profile Close Leethal]

Re: Severe clunking noise

Hi Tonkatuff,

What you describe sounds like a transfer case issue to me, you said you have removed, opened and checked the transfer case though.
Did you fully strip the transfer box ? That is did you remove the front yoke and check the internal splines and the output shaft splines ?
2 of the failed transfer cases I have seen both had stripped splines in the front output yoke & shaft.

Don't just jack the front up and try to turn the shafts by hand as you won't be able to put enough load on the shafts to get it to "slip" over the damaged splines.
Of course if the splines are completely gone you will.

A Prado on the Cape York trip with us in 2009 had a clunking noise from the front begin near Chilli Beach, they managed to get home to Brisbane with it where on pull down it was the front transfer case shaft & yoke splines at fault. I had a good look when it first started, I was fairly certain at the time it was the transfer box but until it was stripped down couldn't confirm it.

Lee

[tonkatuff Lurker Find all posts View Profile Close tonkatuff]

Re: Severe clunking noise

Yeah Lee I think it may be the yoke in the transfer. I am currently driving it with only the rear tail shaft connected and has no problems. I have replaced everything else front Tail shaft front diff front cv's, axles and hubs. To my dissapointment to still have the problem. 6 different mechanics cant work it out and just want to do exploratary surgery to find it, but I think I have done enough of that myself. So i will replace the transfer next in a week or so, and hopefully then I will be hearing nothing but quiet..
To answer all the other questions all the mounts are ok(as new) wheel nuts are tight all the simple things were checked first and replaced first if suspect, hence my list of parts replaced.

I do have another problem that I have been learning to live with, that happened after driving through some large swamps. That is that when using the sub tank it now pumps all the fuel into the main tank and I mean with in a matter of half an hour when the car is running it will completely empty the sub tank and the main tank takes on the fuel. You can actually sit there and watch the sub gauge go down and the main go up. And this only happens on use of the sub tank.. Any suggestions here. Toyota never got bak to me with this one..

[lugueto Junior Member Find all posts View Profile Close lugueto]

Re: Severe clunking noise

I currently have the same problem. Mine is an auto, when I start going uphill applying too much gas, or when I step on it and overdrive kicks in, it makes the severe clunk youre referring to. Most mechanics conclude that its the Transfer case's belt, which drives the front pinion for the front driveshaft. They say these tend to stretch, causing them to have a loose fit and skip the pinion's teeth when under load (mine carries 300kg over the regular stock prado, so its constantly under load..) Replacing it is pricey, at least in my country. Hope this helps, its harder to explain when writing in english lol.

Cheers!

[tonkatuff Lurker Find all posts View Profile Close tonkatuff]

Ok thanks everyone for their help with this and sorry I did not get bak sooner, but lost all my login detail. Anyway the issue ended up being the transfer case.I replaced this with one from the wreckers that had about 100k on it at a cost of $700. After 5 different mechanics different opinions if I had of got a mechanic to fix the problem it would of cost me a fortune, as they all wanted to go on a fishing expedition and not one of them suggested the transfer. I think I always new it was going to be the transfer but cost wise kept drifting away from it and also since I had previously opened up the transfer and it looked like new in there kept concluding it wasnt. Anyway now I have a spare front diff center which may just end up with a locker in it in the near future. and a spare transfer case for parts.. Thanks again for all your help and suggestions, I am now bak online here so feel free to add me and check out some new photos..

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Sounds like backlash to me, most likely in the front diff, there is a crush tube that the pinion gear goes through, it is there to soften the shock load to the diff. If it cops too much shock, the tube crushes slightly, this then affects the diff backlash, so you now have too much backlash, the only way you can rectify it is to overhaul the front diff

[Jake sum Lurker Find all posts View Profile Close Jake sum]

I have clunking also can't figure out and oil from front output on t case

[Brett1979 Avid PP Poster! Find all posts View Profile Close Brett1979]

For anyone else with the fuel issue mentioned, i had the exact same fuel transfer issue in mine a couple of years back, but that was due to tearing off a fuel line going into the fuel solenoid on a 4wd track. A good sized stick did it. My mechanic twice replaced it with the wrong part meant for a Landcruiser which did what you're describing. 3rd attempt and they fitted the correct part which stopped the issue. Both solenoids shared the same part number or something I was told.
If you replace your fuel solenoid it should fix the issue.

[Leethal Advanced Member Find all posts View Profile Close Leethal]

If the front output seal is leaking ensure you keep the transfer case topped up otherwise you will damage all the internals.

Try removing the front driveshaft, engage the centre diff lock and go for a drive.
If the noise is gone you have confirmed the source is either transfer case or front diff.

Lee

[Jake sum Lurker Find all posts View Profile Close Jake sum]

If the front output seal is leaking ensure you keep the transfer case topped up otherwise you will damage all the internals.

Try removing the front driveshaft, engage the centre diff lock and go for a drive.
If the noise is gone you have confirmed the source is either transfer case or front diff.

Lee

thanks pulled transfer apart all seems good clean fluid every thing is doing what spose to thinking it's front diff very toothy sounding and fluid was creamed but no metal in it feels a lot like it from feel in drivers seat