Diagnosis of noises needed

[GEK064]

You’d expect noises from a 12 year old car, but I now have three that I need help to find and fix.

1. Coming from outside the car around the A pillar or similar, a noise as if the wind is rushing through a hole or gap (no the window is not open). I first heard it about 2 years ago, (I think shortly after the TJM bullbar) and it was solved (actually masked) by the road noise of the Bighorns. Bighorns are now gone and the noise is there at about 50km and upwards.? Any ideas?
2. Whenever I switch the car off and get out it appears the compressor or something is making a noise like growling? SLS does not sag.
3. Just heard this a couple of days ago. Whenever I accelerate or remove acceleration a metical ping or tick comes from under the car. Not really heard when the windows are up. Happens on both LPG and petrol.

While ignorance is bliss and I could increase the volume of the radio I’d rather find and fix the gremlins.

Any ideas?

As a thought can I paste noises into this message box.

[AussieAub]

I have, and had, 2 of those noises.

No 1: Pretty sure my "wind noise" is coming from ill fitting, or worn, rubber seals around the doors. At some point my drivers side front and rear doors have been extensively repaired (and not that well either!), so mis-alignment of hinges could be the issue on mine too. But my Hankook muddies and radio help supress that!

No 2: Can't help, sorry!

No 3: Slight ticking is common when the exhaust flange gasket bolts come loose (where the down pipes attach to the rest of the system - 3 bolt connection). Usually just a quick nip-up should suffice, or you can add a spring washer to stop the nut from slipping. That's what I did with mine and seems to be good for some time now.

Cheers again,

[Blknight.aus]

the tick/ping...

CHECK YOUR DOUBLE CARDEN JOINT NOW.

yes, its in capitals for a reason, I also normally do it in RED and under line it...

like this..

CHECK YOUR DOUBLE CARDEN JOINT NOW.

the wind noise is probably a vortex on the door seal at the back of the door, try closing the door on a length of packing box cardboard and take it for a drive, it can also be the trim on the top of the windshield

no idea on the growling, that one I'd have to hear.

[Scouse]

1. Loose exterior A pillar trim?

2. Td5 ? It's not the centrifugal filter winding down, is it?

[biggin]

1. If it's like mine, you will be able to slide a piece of paper between the door window frame and the seal. If so, you can place a length of say 5mm flex behind the seal to raise it slightly for a quick fix. Or for a permanent fix, pull the door trim off, loosen the window frame, and re-tighten with the frame angled a little more toward the seal.
Worked for me anyway.
2. Not sure, but doesn't the ABS modulator normally have a fit every now and again.
3. Well, Blknight has that one covered.

Cheers,

[alien]

1. As the others have said

2. Posibly the SLS compresor, mounted on the chassis under the front passenger seat area.

3. As said but check the Cardin Joint($$$ if it "lets go") first then head to the exhaust.

[AussieAub]

Whilst I certainly don't disagree with Blknight's comments, just check those flanges first.
Those carden joints are a HUGE issue. But when I noticed my ticking and posted up here a while back now, I went into panic mode over the carden joint issue due to the amount of people telling me it was the CJ's. What I hadn't mentioned on that post was that that particular issue had been "fixed" less than 2 weeks prior.

Another forumite pointed me in the direction of the flange bolts. Got under and had a look with a socket set, and they were loose. Tightened up and hey presto no more ticking, for a while anyway. They came loose again and thats when the spring washers were installed. Prob over a year ago now, and no ticking since. :)

Like I say, I am in NO WAY bagging Blknight's comments, he has offered me many useful and correct diagnosees(?) in the past, but I'd just check those bolts before having a coronary!! :cool:

Cheers,

[justinc]

As regards the wind noise, check that the bailey channel in the rear doors that the window slides up and down in hasn't slid down with the window, I have had 3 D2's do this all of them rear doors, 1 RH side 2 LH side. all had dropped by up to 25mm in the top corner where it meets the top seal. This creates a whistle like non existent roof racks at times. I just pull it up with thin nose pliers, it'll stay there for quite some time before needing it done again usually.
I agree check exhaust flanges if V8, and DOUBLE CARDAN JOINT is a priority to inspect carefully AS THE NOISE APPEARS ON AND OFF THE THROTTLE.
The SLS compressor will growl 3 or 4 times occasionally after switch off if parked on slopes as it will try and level the vehicle slightly.

JC

[Blknight.aus]

it goes without saying that you're checking the whole shaft, not just the DC itself.

any disjointery on that particular bit of spinny steel is going to be at best un-nerving and at worst will leave you with you with that, "why does my wallet hurt so badly and where did all my fun money go?" feeling along with the sudden realization that your car is now an insurance write off.

[GEK064]

Brilliant - thanks to all of you! Working in product development I know the process of trial and error all to well and given the experience of ownership behind these answers, you've probably saved me a couple years worth of trial and error! I mean I would have that time just looking at the front seals never mind the rear ones...and how do you determine the noise mainly occurs on a slope? Again thanks.

As to the exhaust/Cardens joint I'll check both tomorrow as I'm getting the exhaust looked at to understand what can be done about improving power and fuel consumption (heard a lot of stories and a mate of a mate volunteered to talk it through with me.

Just so I get the right terminology - is a Cardens double joint the same as double universal joint which is the same as hookes joint?

About two years ago I broke the front one - after ignoring all the typically signs -won't be making mistake again!

[justinc]

Brilliant - thanks to all of you! Working in product development I know the process of trial and error all to well and given the experience of ownership behind these answers, you've probably saved me a couple years worth of trial and error! I mean I would have that time just looking at the front seals never mind the rear ones...and how do you determine the noise mainly occurs on a slope? Again thanks.

As to the exhaust/Cardens joint I'll check both tomorrow as I'm getting the exhaust looked at to understand what can be done about improving power and fuel consumption (heard a lot of stories and a mate of a mate volunteered to talk it through with me.

Just so I get the right terminology - is a Cardens double joint the same as double universal joint which is the same as hookes joint?

About two years ago I broke the front one - after ignoring all the typically signs -won't be making mistake again!

See here GEKO64,

Constant-velocity joint - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Constant-velocity_joint#Double_Cardan)

They will be pretty easy to check, look for any rusty type powder and excessive play etc.

V8's are pretty hard on them as the Cats are close to it drying out the grease etc from heat.

JC

[GEK064]

I feel like a Hypochondriac*- would a new 4.6 motor increase the load substantially? Do they have serviceable nipples?

[Blknight.aus]

they can be rebuilt with greaseable UJ's

the best ones have fittings for nipples but dont have the nipples fitted they have a hex socket screw fitted in them that when its time to grease them you remove the hex screw, install the nipple, grease it, remove the nipple and re-install the hex screw.

leaving the nipple in place can wind up leading to a damaged nipple that then lets corruption into the joint or that requires dissasembly of the joint to get the old nipple out so you can put a new one in and grease it up.

[clubagreenie]

I've tried to work out, apart from what I know, what the difference betwen a DC and a back to back uni is. I had a new front shaft made for my RRC years back and it had two unis at onw end and the centre was just more or less two flanges weled together (but a machined part). Yet the DC's from the threads seem to have a centre ball which is the expensive, hard to replace part.

Thoughts and opinions?

[biggin]

I've tried to work out, apart from what I know, what the difference betwen a DC and a back to back uni is. I had a new front shaft made for my RRC years back and it had two unis at onw end and the centre was just more or less two flanges weled together (but a machined part). Yet the DC's from the threads seem to have a centre ball which is the expensive, hard to replace part.

Thoughts and opinions?

I think you've nailed it.
As usual UP has it covered:
www.discovery2.co.uk / Workshop :- front and Rear propshaft (http://www.discovery2.co.uk/propshafts.html)

[Blknight.aus]

correct.

a double uni is usually done on a short lenght to correct misalignment on machines. typically its just as you described it 2 UJ flanges welded together, occasionally they might be bolted. they get their slip alignment from having one side running on a sliding spline like the rear output from a rear wheel drive auto and can run at nearly the angle limit for normal UJ's

A Double Carden shaft has an alignment mechanism built into it and forces the 2 universal joints to move through the same range to achive the "angle" they need to achieve (half each so a 30 degree bend is achieve by both UJ's in the joint moving 15 degrees). The Centralising mechanism usually runs out of travel before the UJ's do and most stressed part is the centering mechanism, Once its worn it begins to "wander" and when that happens the UJ's get ever so slightly out of alignment and the process begins to compound.

I've had a quick look at the geometry and you might be able to get a shaft custom made that runs 2 CV joints as opposed to the DC but thats likely to increase the loading on the Tcase font out put.

[clubagreenie]

DO NOT use a CV on it, trust me my RRC front replacement double uni shaft was replacing the original one that had a CV (fitted from "factory" when they did the borg warner 35 auto conversion). On overrun it rattled and clanked something chronic, new CV lasted about 7-8 months, a month or 2 longer than the boot.

Actually I see the difference now. The DC with self centring the TC flange and shaft end are "circular" where as the diff flange is only a U shape and is what is used in the double uni shaft. Mark from All spares made it for me and pretty sure the flange/joint/spline was from a county or similar vintage. Worked a treat and was much easier to overhaul and cheaper too.

[awabbit6]

it goes without saying that you're checking the whole shaft, not just the DC itself.

I had a similar metallic 'tick' as I pulled away from a standing start. As Blknight has suggested, it was caused by the front uni in the front propshaft.

The joint itself was fine but it was moving in the front flange. Prior to me purchasing the vehicle, the DC joint has let go (evidenced by the dents in the chassis rail and gearbox from it flapping around). This had caused the front flange to spread open so the front uni wasn't being located properly. New flange and uni solved the problem.

[Blknight.aus]

you have to CV both sides a CV + UJ on a single shaft will always cause problems...

dunno why it does though, in theory it should work.

[clubagreenie]

Perhaps the CV's because of the angle of the grooves hold the shaft central where with the uni at one end allows it to oscillate slightly at the CV end.

[GEK064]

Well I went under and checked all the joints and it seems to be OK. There is about 10mm play on the front shaft and zero on the rear. In that 10mm play a tick clunck noise does appear on both back and forward movements - bearing maybe? Did some reading on replacement of the bearing on a D1 - is it the same process on d2?