In my XH today I noticed a slight knocking coming from the diff. It only happens when I'm coasting, with no braking and no acceleration. It does it in gear and in neutral. I brake, it stops, I apply throttle, it stops. I go faster, the knock is quicker. It is a 3.45 non-LSD diff and 5spd manual that is standard with the tradesman option.

I got home and drained the diff oil, which was replaced fairly recently and there was the correct quantity. Then I took the diff cover off and noticed there is play between the gears in the centre of the diff and the outer spline. I can move the wheels about 5cm (at the tyres) before the outer spline will engage and turn with the drive shaft. This seems to be the only area that has any play in it. Everything else I can see appears ok and nothing obvious is broken.

I don't do burnouts or hammer it, and the ute has 180,000kms on it. What is causing this noise and how do I fix it? Any help would be awesome.

spider gears i reckon. time for a rebuild. also it the pinion and crown have that much play it's due

That seems to make sense, but I don't have much experience with diffs and I'm not sure. Also, I lowered the ute recently, by about 45mm with Pedders front coils and reset standard rear leaves. I have done about 2,000kms since and have had no problems. I was reading about tailshaft angles but I didn't think this would be a problem with leaves and nothing is rubbing obviously. Could lowering it be an issue though?

Rebuilding this time of year is going to be a pain I think and I might try and get an LSD too if I can, but any other ideas as to what the probem might be would be cool.

Check your wheel nuts just to rule that out too.

My diff knocked once too. I nearly replaced the diff but it was wheel nuts.

my old diff did it, the single wheeler that was originally in it. it blew up a few months later when i was doing a innocent u-turn. no hard throttle or anything. just bang. it locked up like a mini spool though. chuffing tyres everywhere.

just source and xr ute lsd or something

Uni joints? The might be noisy when not under load, like you described.

Mike

I've had it up on stands and it is definately in the diff. When I turn the driveshaft or UJ by hand there is a lot of play and it feels quite uneven in the diff. The guys in town are going to have a quick look tomorrow morning but I think I will try to find an LSD for the new year. I hope it is as easy to find one as wildeb suggets, but somehow I don't think it will be.

Thanks for the help.

man wtf it was wheel nuts. i thought i'd check before taking it in and they were reasonably loose on one side. tighten, noise gone.

it's funny how you get these ideas that it's one thing and everything seems to point that way then it's something completely different.

What do I win?