Clunk from under my Prado 90 - With Videos

[Hamish Lurker Find all posts View Profile Close Hamish]

I urgently need some help with a clunk. We are driving overland from Scotland to the Himalayas. We are in Kazakhstan and about to cross some pretty warm inhospitable places and I don’t fancy a breakdown.

I have a loud clunk noise which sounds very metallic. It usually happen with steering input as the sideways load builds up, or when I’m steering over uneven ground at low speed. It sounds like tension builds up and then releases itself with a clunk. It only clunks once and is not a repetitive sound.

I have uploaded a video onto youtube with the clunk. You can see the camera shake, so it’s a decent clunk. The camera is mounted on the 1st cross member back from the anti-roll bar.

Clunks are clearly audible on these 2 videos https://www.youtube.com/watch?v=lptQENwT_ns & https://www.youtube.com/watch?v=uIGBQcGZNRI

I then parked the car up and did lock to lock with the engine on and some steering back and forth with the engine off. There is a clearly audible nocking on the video when the engine is off and I’m steering. Is that normal? https://www.youtube.com/watch?v=SehrgvTNtWY

(full video, https://www.youtube.com/watch?v=1XxNX4ZMrOU , clunks at 3:50 & 4:43. Steering at 9:50. There may be something else you see which isn’t in the short ones)

I have taken it to the Toyota main dealer in Azerbaijan and they were certain that the steering rack was the problem. Hellishly expensive to change out from Toyota and hence I’d like your advice. They suggested part number 44200 60012 which I believe is a RHD steering rack.

What I changed before we started the trip  The spring, dampers (inc top mounts), anti-roll bar links all round, anti-roll bar bushes all round, front upper & lower arm bushes, back upper & lower arm bushes, track rod ends, reconditioned calipers all round, brake pads & discs all round. So it is unlikely to be any of these parts worn.

If you have read all this and watched the videos, I thank you for your time and would appreciate any input.

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

Hi Hamish,

I've watched all of the videos but unfortunately I can't come to any conclusion from them.

The main items I would have suspected are the diffs and the transfer case. Especially the transfer given the camera moves during the sound, and it's under strain during direction changes. However, the transfer, transmission and diffs are all more likely to create repetitive sounds.

Steering on the other hand, would be infrequent, so without performing more troubleshooting I'd have to assume that the Toyota dealership is correct.

There is a couple thing I suggest you try though. First off, when setting the transfer to high range locked - does it act as expected? Ie, the steering should feel very heavy as the drive line is wound up under tension.

Secondly, remove the front prop shaft and test drive in high locked mode. This would test two possibilities - the transfer's planetary gearset (which distributes load) and the transfers chain (which drives the front). If these are a problem the sound may still occur, but with much less strength.

Good luck!

[gphcald Member Find all posts View Profile Close gphcald]

Hamish
It may be the mounting rubbers for the steering rack,i had a knocking sound come from mine and it was this, I got it early, if it was borderline before you left and the rough roads have made it worse then it could be it. its a simple but fiddly job

my 2c worth

Rgds

Gerry

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

Learning from my own experience just because you have replaced with a new one dont rule out that part for failure. ...
Also have you greased up the slip joints on the prop shafts? If you have you may have too much grease. .. causing an airlock.... once it releases under pressure it probly wont do it again till driveline foward and backward tension is released

[chainsnore Lurker Find all posts View Profile Close chainsnore]

I had something similar, turned out the needle bearing in the bottom of the pinion had got water in and rusted, then collapsed. Is it notchy to steer? I end up replacing the pinion valve body with another rack i had lying around.

[brissy Member Find all posts View Profile Close brissy]

sounds like the rack, clunk when changing direction , have you slid off the rack end boots to check play in the rack ends, or as suggested above pinion needle bearing calapse would also make the clunk with steering pressure change left to right ,
let us know the outcome, best of luck with your trip

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

Hamish
It may be the mounting rubbers for the steering rack,i had a knocking sound come from mine and it was this, I got it early, if it was borderline before you left and the rough roads have made it worse then it could be it. its a simple but fiddly job

my 2c worth

Rgds

Gerry

+1 You can see the steering rack moving in the stationery vid.

[Hamish Lurker Find all posts View Profile Close Hamish]

Hello Everyone,

Sorry for the late reply but we've just completed some 2500 Km travelling through only a small part of Kazakhstan on some of the worst roads/tracks I've ever seen. We are now in the Northern capital city. For all the technical junkies I'll cut to the chase and describe the problem (now fixed) and then tell a wonderful story about a Toyota Main Dealer (I know they are few and far between).

I went into the dealer armed with all your suggestions and the information from Toyota in Baku (Azerbaijan). Kazakhstan is the land of bodge jobs and making do, they were shocked at the idea of a complete rack replacement as suggested by Toyota Baku. After explaining my (your) ideas, we went for a test drive with their senior mechanic whom knew what the problem was right away, especially after a poke around on the ramp. We replaced

1) The steering rack end (+associated clips and oil)
2) 2 circular bushes on the steering rack
3) 1 large U bush/grommet on the steering rack

All of you who thought it might be the rack end or bushes were correct. Thank you.

All of you who said 'just cos you've replaced it, doesn't mean it isn't the problem' are correct. Thank you. I replaced the steering rack bushes before I left (20,000 km) ago, they were made by Whiteline. Not good, especially since all of the other bushes (upper/lower arm front and back, panhard, etc.) are all Whiteline replaced 20, 000 Km ago.

The clunk is gone and the steering slop (which I wasn't that aware of) is now gone.

Now onto the lovely story about the Toyota Main Steeler. We turned up and none of them spoke a word of English and my Russian is terrible, Kazak even worse. They soon got one of their friends on the phone who acted as translator for the next 10 hours ! A very kind lady indeed. They diagnosed the problem for 20 USD but said they couldn't get spare parts for 2 weeks. Bummer, we are screwed. No we are not, the guy who hooked us up with the translator is now arguing with his boss about something, later I would find out why. Bare in mind that this dealer is every bit as professional and slick as a western one, all the comfort, tools and toys.

He beckons me into his car and off we go. We end up in a Kazakhstan bazaar, specifically for counter-fit Toyota parts. The guy made sure his Toyota credentials were well hidden in his pocket before heading in. We later returned to the dealership with the bag of contraband and the mechanics got to work. Fake Toyota parts, proudly fitted by Toyota mechanics, warranty and all :-)

For the parts, labor and alignment it cost 180 USD, 240 AUD or 116 GBP ! Pretty cheap. Lets see how long they last. We also got fed twice and endless cups of tea while waiting comfortably in an AC showroom. Lovely and genuine people, a great experience.

Many thanks... Hamish

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

Great result.