Strange noise.

[Harry]

The Bighorn I sold a while ago [remember the handbrake saga]has come back to haunt me.No problems with responsibility but the woman I sold it to seems to think I'm some sort of Isuzu expert.The truck has started making a rumbling grinding noise.Sort of a cross between a chattering hole saw and trying to change gear without the clutch.It's intermittant and seems to be coming from the front.I've fixed the exhaust {she backed into something and bent the pipe].The wheel bearings are ok.It never made the noise before I sold it and the only changes I made to it were to fit her motor [better than any of mine] and replace the auto hubs with her manual ones.The needle rollers in the steering knuckles are a possibility but one of mine was stuffed for years and never made that noise.Does anyone have any ideas.Thanx in advance,
Harry.

[geeves]

Im sure you would of checked the brake pads but will mention it anyway?? Could also be the spigot bearing in the clutch.
The big one is check the bolt in the crankshaft pully If this is loose the pulley rubs on the plastic cam belt cover. Also check for rub marks on the radiator

[mudgrip4]

Once had a prolonged grinding noise - several minutes and intermittent - from the front and it turned out to be the little needle roller bearings on inside of front hubs. There was nothing left of them - just the outer shell. Extracted them, changed them both sides and end of problem. A pair cost about $30 or so from a bearing outfit. Lot of noise from a little bearing. Be worth checking I think

Mike

[Graham]

Mine occasioinally makes a noise similar to missing a gear shift in a manual.
Its normally from the front hubs after disenaging 4WD but leaving the hubs locked (manual hubs). Goes away after driving about 10m so I'm not too worried. (should I be?)

Graham.

[Harry]

Checked the pully and the brake pads.Spigot bearing is a bit difficult.Forgot to mention her garage has had a look but couldn't find anything.But the truck didn't make the noise for them.The noise is almost enough to require an undie change when it happens.Apparently the truck was left stuck in a swamp overnight so if the 1/2 shaft seals were a bit tired I'd say the needle rollers are stuffed.Will pull the knuckles out tomorrow and have a look.
Regards,Harry.

[geeves]

Does it make the noise in 2wd? If so look elsewhere unles the free wheels are stuck on. If the half shafts aint turning how can they make a noise

[Harry]

Hi Alan.I've just come to that conclusion myself.I've only heard it in 2wd and the front axles shouldn't be turning.The rh f/w hub was empty [her garage reckoned the spring was missing].The lhs was intact but quite warm as though it had been spinning.Thinking back when I had the truck it had auto hubs and occasionally seemed to "slip" in 4wd on the gravel part of my driveway when shifting the boat or trailer around .I put it down to the auto hubs and fitted her manual hubs after which it seemed ok.Just wondering now if there's a problem in the transfer case or it's selectors.It looks like I can open the transfer case without removing the gearbox.I have 2 spare gearboxes which I can use for parts.
REgards,Harry.

[geeves]

A free wheel works by engaging 2 slines. If it was slipping there would be obvious damage inside but it wouldnt cause a lot of heat. I would be looking at the brakes or wheel bearings again. Also look at the tyres for any unusual rub marks

[Harry]

Not sure of the reason but I cleaned the auto hubs that were originally on the truck,fitted them and did a 60km test drive and the noise didn't happen.So its going back to it's owner tomorrow and she can let me know if the noise comes back.I don't know how one possibly stuffed manual hub could make so much noise.
Fingers crossed and thanx for the input .
Regards,Harry.