New noise in MQ (maybe gb?)

[Heathx4]

Folks, hoping someone might be able to offer some advice on the latest noise to develop in my old MQ.

On the way back from a trip up Nelson Bay way, we noticed a metal rattle noise evident on some bumps along the 100k/hr sections. I figured I smacked something up a bit closer to something else (I was bellied out a few times during the day) and it was contacting. Also, on the last corner under power there was a brief terrible metalic scraping noise. I checked the underside later and couldn't see anything obviously wrong. Anyway, the noise disappeared and the next couple of short trips had no issues (maybe a slight metal rattling over decent bumps on the black top, nothing that stood out though).

But in the later half of my latest trip, and then very obviously on the way home, the noise returned. This time however, it was constant under any acceleration, mostly in 3rd, but also in 2nd and 4th, less obvious in 1st (standard 4sp+L28). It was an awful metallic rasping/scraping noise, seemingly from the drivetrain (gearbox/driveshaft area), constant at any rpm or speed, but only under acceleration or very briefly over bumps. Today it is just mildly less severe, but occurs in any gear now.

I tried putting the rear axle on stands, and driving the thing hard in 2wd, even with the hand or foot brake on, but couldn't reproduce the noise! I tried in FWD (rear shaft out) but unfortunately because my front shaft is shagged, I couldn't hear much over the noise of that! I'm pretty sure the noise was still there. Noise doesn't seem to change depending on high/low range. So I'm thinking gearbox at this stage. I checked oil at the fill point and it was over flowing but fairly clean. I don't have any spare gb oil at the mo', so I didn't try draining it yet and looking for metal shards. Any ideas what else I can check?

Oh, by the way, the rear shaft was a bitch to get out, and I managed to seperate the slip joint pulling it out, and am not completely sure how to put it back together! Firstly, there was a thin, flat metal ring that was left on the spline that is bent and I can't place, and secondly, at what angle do I rejoin the two halves?

[Patroler]

Sometimes the handbrake drum can rub which makes a scraping sound, but that would do it under no load.

constant at any rpm or speed

Does the sound stay constant even if the motor is revving hard in first or just idling along in fourth?, and are you sure vehicle speed doesn't affect the sound?
Normally gearbox noises will change with either engine revs or vehicle speed?
I'd be draining both gbox and tcase oils and looking at the magnetic plugs - found a tooth on one once!

[Heathx4]

Yeah I thought handbrake drum, cause when I first removed the rear tail shaft and drove it in 2wd, it started very similar scraping really bad. I jumped out of the car and realised that without the rear shaft on, the drum cover had slipped off and was really dragging on the cross member! Once bolted up though, it didn't seem to be the issue.

Yeah, speed/sound relationship is funny - nothing at all when coasting or slowing down. Under any load though (accelerating or up hills) it comes on. Then regardless of gear, speed or rpm (as long as still under load), it is the same sort of scraping.

Any have the proper breakdown of the rear shaft so I can at least put that back right?

Will definately check mag plugs, but I had a bit of budget mishap, and can't actually afford any gb oil for the time being!

[bazzle]

Fan or handbrake drum.

Tailshaft goes with each inner in line. O------}{---O

Bazzle

[Heathx4]

Ha, you guys are too good. Of course it was the handbrake drum! My melodramatic mind had run away again and convinced me it couldn't be. Of course, the noise developed not long after dropping the car fairly heavily on the cross member - and sure enough, after removing the cross member today, the noise disappeared!

There was a decent, but not massive scrape mark on the inside of cross member, so I think (and really hope!) that's solved it. Now, last time I pulled the member off (hmm, don't take that line out of context) I bashed and drove over and high lift compressed it trying to get it a bit further away from drum, but it hardly budged at all. I was thinking some light angle grinding might help, but hope I can make do with some attention from Mr Hammer. The issue at the moment though, is that last time I tried to put the member back on, the bolts wouldn't line up (they didn't come out real easy either), hence the compression efforts with the high lift. In the end I ended up forcing the bolts in, hoping never to have to remove them again! Well, I did manage to get them out this time, but their thread is well messed up. I guess it would be worthwhile replacing them now, if I can find something suitable, and work the new stuff into whatever is left in the chassis rail nuts. I'll probably drill the bolt holes in cross member a little wider too, so I don't have to force them back in. The problem I see with that is, a little extra girth freedom will make it easier for the member to squash up again. Would that be right - would the compression provided by the bolts in the chassis rail help to hold the downward arch shape of the cross member?

Tailshaft goes with each inner in line. O------}{---O

Ah, that would probably mean I got them 90 degrees out. I thought for some reason the unis had to be out of phase so they didn't resonate together or some such. I don't quite get your diagram though. You mean looking at the complete shaft, the two unis will look the same, right?

|{-}-------slip joint-----{-}|

Any suggestions on where this thin metal ring (more like a flat donut, but with the flat surface at an angle to the circle, so it could be a peel off a cone) might go? It doesn't really look right where I've left it, on the visible section of the spline, but doesn't look like it serves any great purpose either.

[Screwy]

Ha, you guys are too good. Of course it was the handbrake drum! My melodramatic mind had run away again and convinced me it couldn't be. Of course, the noise developed not long after dropping the car fairly heavily on the cross member - and sure enough, after removing the cross member today, the noise disappeared!

There was a decent, but not massive scrape mark on the inside of cross member, so I think (and really hope!) that's solved it. Now, last time I pulled the member off (hmm, don't take that line out of context) I bashed and drove over and high lift compressed it trying to get it a bit further away from drum, but it hardly budged at all. I was thinking some light angle grinding might help, but hope I can make do with some attention from Mr Hammer. The issue at the moment though, is that last time I tried to put the member back on, the bolts wouldn't line up (they didn't come out real easy either), hence the compression efforts with the high lift. In the end I ended up forcing the bolts in, hoping never to have to remove them again! Well, I did manage to get them out this time, but their thread is well messed up. I guess it would be worthwhile replacing them now, if I can find something suitable, and work the new stuff into whatever is left in the chassis rail nuts. I'll probably drill the bolt holes in cross member a little wider too, so I don't have to force them back in. The problem I see with that is, a little extra girth freedom will make it easier for the member to squash up again. Would that be right - would the compression provided by the bolts in the chassis rail help to hold the downward arch shape of the cross member?

Tailshaft goes with each inner in line. O------}{---O

Ah, that would probably mean I got them 90 degrees out. I thought for some reason the unis had to be out of phase so they didn't resonate together or some such. I don't quite get your diagram though. You mean looking at the complete shaft, the two unis will look the same, right?

|{-}-------slip joint-----{-}|

Any suggestions on where this thin metal ring (more like a flat donut, but with the flat surface at an angle to the circle, so it could be a peel off a cone) might go? It doesn't really look right where I've left it, on the visible section of the spline, but doesn't look like it serves any great purpose either.

Yes when putting the shadt together u have to have them in phase otherwise u will get vibs.
they have to look the same and be the same way with the flats hard on the ground on both sides while putting it together.

the ring goes on the outside ot the Slip joint grease seal to stop shit from getting in there and stuffing the shaft.
If its come off the sea, u will not be able to put it back on.
but as long as ur shaft is nice and full of grease u will not need it.

screwy