Hi

I'm 7 months / 34,000kms into my trip across Asia in a 1993 Toyota Hilux Pickup - 2.4D 4x4.

There's a backround noise when driving, which seems to come from the engine / front bulkhead. It's particularly noticeable through the clutch pedal, and is most apparent when revving the engine with the clutch down, or changing gear. The noise is then a light tapping, spinning-down noise. It sounds too light and external to be big end / main bearing noise. I would blame the clutch release bearing, or input bearing in the box, but wouldn't these be still when the engine is revved with the cluch pedal down? My suspect is a bearing in the PAS pump or alternator. The timing belt has done about 55,000 KM/S (not miles), and looks like new.

Theres a separate (I think) vibration, which is very apparent as you go into 4th at 45km/h through to about 50-55, then goes above this. It is worse when accelerating / going up hills. (This is in 2WD, I very rareley use 4WD). I have replaced the centre bearing, and had the UJs checked - there is a tiny amount of movement in them, but everyone says this is fine.

So I'm a bit stumped about this. It has been getting gradually worse over the last 20,000kms.

Any suggestions would be welcomed

Thanks

Daniel

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4.5 years around Eurasia in a Toyota Hilux|http://eurasiaoverland.wordpress.com/
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Hi Daniel, just some quick thoughts:-
check the props again and grease the uj's and the sliders if you have them, I'm not sure there should be any play. Stick everything in neutral and see if there is more play than last time.
check engine and gearbox mountings
sorry, can't be more help.
Good luck
Chris

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Chris
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"Never have a stupid argument with an idiot - he gets a lot more practice than you"
there I go again
not too hard really

Hi Daniel,
Your thrust bearing is turning when you press the clutch in, that is why it's a bearing or in some cases a carbon type pad. I can't remember if your Toyota is a cable operated clutch or hydraulic, if it is cable then you need to adjust it to put some free play in it, about 1/8 th inch at the clutch fork. The thrust bearing would then clear the pressure plate in the off position and if it is the bearing that is causing the noise it will stop until you press the clutch. Some hydraulic systems also have an adjuster at the slave cylinder end.
I trust you have checked the oil in the gearbox.
Have you used the listening stick method to trace a noise ?
A long screwdriver or long socket extension touched to a unit and the other end at your ear while the engine is running.
BE MOST CAREFUL IF YOU USE THIS METHOD OF DETECTION AND MAKE SURE YOU HAVE SOMEONE WITH YOU.
After saying that I have used this method many times without misshap.

Cheers
Ian

Hi. The vibration sounds like it could be a propshaft. It could simply be a weight that has come off the prop (they are tiny weights) or maybe a damaged or worn UJ. The other (main) problem sounds like the clutch release bearing. This is spinning with the clutch cover (that is bolted to the flywheel). Try sitting with the engine running and depress the clutch pedal and rev the engine on and off, up and down etc. If there is a problem with the release bearing you should be able to hear/feel it (maybe!).
It could also possibly be the input shaft bearing in the gearbox (like you say), I think this will make a humming sound under load or over run.
As a matter of course check the oil level in both gearboxes anyway.
Oh, and check the rear prop centre bearing again if you can.
To check the bearings in the PAS and alternator, place a big screwdriver (or similar thing) between your ear and the bearing area, press the flat screwdriver end on the casing near the bearing, then press your ear to the screw driver handle with the engine running. Be careful though, watch out for spinning fans, belts etc!! You can hear the noise of the bearings, they sound very noisy anyway, but if there is a worn one it sounds even more noisy! It's hard to explain, but play about with different sounds on the engine and you should be able to get a feel for what is normal. Or if you have a stethoscope, that's even better. You can actually buy proper stethoscopes for doing this very thing.

Right, that's a lot of writing for me, I'm off for a hot chocolate and a sit down...

Cheers,
Matt

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www.mattsavage.com
VIAIR - 12 & 24 volt compressors and systems. Tyre levers, Land Rover parts, Sand Tracks, Allisport Intercoolers, Overland Prep, and much more...

I had a similar rattlly noise (well actually dozens) in the Defender - turned out to be the alternator. Fixed that and then the belt tensioner started... Sorry not much help!

I am off for a glass or two of Nederberg with our staff before we close down and I pack up the troopy to head for Mali tomorrow a.m.

Lucky bugger enjoy

stuck here in the cold with sausage butty

__________________
Chris
-----------------
"Never have a stupid argument with an idiot - he gets a lot more practice than you"
there I go again
not too hard really

Many thanks Chris!
got delayed a couple of days... :-( but now packed and checkinh fellow Hubbers for the last time for a while.

Hope everyone 'here' has a great Christmas and New Year
Gil
(curently enjoying a nice glass of water due to too much festive cheer last night)