so i have this knocking in the front end. it is louder in 4wd but sometimes noticeable in 2wd with the hubs locked. my best guess is a u joint but i couldnt notice any problems while under the truck. if any one has experienced this and can help let me know oh yeah. it is driveline related not an engine noise

 

Just for the hell of it:

Check your body mounts. I had a similar problem, to check rock truck when parked if it creeks or knocks it's your mounts.

good luck diagnosing your problem!

 

May be the wheel bearings if you can hear it in 4wd and 2wd. I'm assuming by your name it's an 88 Runner? Manual hubs, so the drive-line isn't in motion until you lock in the hubs and/or put the transfer case in 4wd. Sence you can here it in 2wd too, sounds like the bearings IMO. Possibly the ball joints, but I'd do a quick inspection. Jack the front end up and see if there's any play in the wheels.

Edit: Just re-read it and I think I misinterpreted it... Can you here it without the hubs locked and the transfer case in 4wd? If so, you assumption about the U-joints may be right. They often make the most noise just before they go, but can still feel solid.

 

so im pretty sure its a u joint. how do i tell which one(transfer side, diff side)
thanks
marc

 

Replace them all. It's cheap insurance.

 

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