Groaning 405

mrbump · Post by **mrbump** » 29 Oct 2004, 17:32

Hey,
There is a strange groaning sound coming from the front of our 405. Initailly I thought it was a wheel bearing, but after several attempts at feeling for any roughess in the juacked up wheels, I am sure that it isnt. The wheels both spin freely for ages, and there is no lateral play whatsoever.
Whilst looking for the cause, I have changed a driveshaft (because the cv was knocking anyway) and the noise remained, changed the other (long) driveshaft in case it was the little intermediate bearing that had failed, and the noise remained, checked and changed the gearbox oil molre than once.
The noise got gradually worse over a couple of weeks, and now has been the same for about a fortnight. The only influencing factor to the noise seems to be road speed. Power on, off; in gear, not; cold, hot; cornering etc does not have an effect, just how fast you are going.
I suspect the differential next, but dont really want to do it if I dont have to. How difficult a job is it? Is it just a case of removing the drveshafts and unbolting the diff casing under the car? Surely not!!
Or has anyone had a wheel bearing problem like this that does not affect the dynamics of the car at all and does not show up in any play at all? Is there a better test then this? Loosen off the hub nut a bit maybe?
Any ideas at all would be appreciated
cheers
greg

bxbodger · Post by **bxbodger** » 29 Oct 2004, 17:47

If you can't find anything, then driving it until whatever it is breaks usually identifies the problem!
It sounds like something's rubbing to me-mudflaps, loose cables, wonky wheeltrims rubbing on the tyre, etc?- which may only make contact when the cars on its wheels and not jacked up.
I spent ages trying to track down a speed variable clicking noise which sounded mechanical and terminal, but which turned out to be a bit of loose wheel-trim rattling around- it only went away when I drove it without the trim on!

beezer · Post by **beezer** » 29 Oct 2004, 18:55

Have you tried jacking up the whole front end and running it in gear? If it is a differential problem you should be able to track it down.

meexi · Post by **meexi** » 30 Oct 2004, 03:47

I would try the bottom engine mount the one where the driveshaft goes through to see if the rubber has failed this happened on my old bx

mrbump · Post by **mrbump** » 01 Nov 2004, 20:48

Thanks guys,
I have tried running it in gear with it jacked up and the sound is not there!! It also definitely sounds more fundamental than trim etc, it is actually stating to cause vibrations that can be felt in the cabin.
I did change the bearing that is housed in the same alloy mount as the rubber engine mount, but it didnt change. I dont think that the rubber mounty itself would cause this noise.
Driving it till it breaks is definitely the cheapest method of diagnosing the problem, but not neccesarily the safest!! [:p] This seems to be the only way at the moment though as I have had a second opinion from our local peogeot dealer, who said that it was two front wheel bearings and the timing belt???[}:)] Nedless to say we told them we'd think about it (£780).
I have a spare diff if it that that goes, so I'll keep an eye on the wheel bearings and see what happens i think.
Cheers

oilyspanner · Post by **oilyspanner** » 01 Nov 2004, 21:13

Could be the wheel bearings, I had a similar one, couldnt decide which side it was, turned out to be both of em;) noise became so loud that pedestrians were looking and pointing! no play whatsoever and sounded quiet enough when jacked up and spun due to no weight on them, both sides had transverse cracks across the inner races.
Stewart

jeremy · Post by **jeremy** » 01 Nov 2004, 21:43

I think I agree with Stewart. If your front tyres are equal size then the differential itself if stationary when going straight ahead and so cannot make any noise. If the tyres are not equal then it will reduce and stop on corners of a certain radius when again the differential would stop moving. The final drive or gearbox itself could be at fault but I'm certain that any noise would be load dependant and would be present on drive nad not on overrun etc.
Another thing worth looking at is the mounting on the top of the gearbox (bottom of the battery tray?)
jeremy

beezer · Post by **beezer** » 01 Nov 2004, 22:23

Meezi's idea about lower engine mount sounds a distinct possibility. It could explain the vibration coming through into the cab Wheel bearings would likely change as you steered and there would be a certain amount of play albeit very slight at first. Timing belt? Well they can be noisy if badly tensioned but sounds unlikely. Belt on a 405 is a doddle. Only difficult bits are getting a rod behind the starter to lock up flywheel (I made a cranked affair) and undoing crankshaft pulley bolt (I can get a belt on my 205 without removing pulley). Belt should cost under 20 quid.

beezer · Post by **beezer** » 01 Nov 2004, 22:26

Meant Meexi!

rg · Post by rg » 02 Nov 2004, 03:04

A suspected diff bearing (known to be weak on the BE3 box) finally prompted me to take my 405 for it's final drive at 251K.
What's the gearbox oil look like? Gravy? If so, then suspect a diff. bearing.
rg

ItDontGo · Post by **ItDontGo** » 02 Nov 2004, 17:50

When did Citroen make a 405?

Kowalski · Post by **Kowalski** » 02 Nov 2004, 17:59

Peugeot and Citroen are both owned by PSA, and they share a great deal of their components.

tfurness · Post by **tfurness** » 02 Nov 2004, 20:26

I had a problem like this a few years ago.
The noise turned out to be wheel bearings (both) although there was no play. The car drove straight and true but the problem was caused by the tracking being out. So I suggest you get it tracked, most places check it for free. The load on the bearings made them noisy and it was only out a few millimetres, not much. The car remained quite for 20k after that until sold.
Hope this helps -Tom

ItDontGo · Post by **ItDontGo** » 02 Nov 2004, 20:38

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by ItDontGo</i>

When did Citroen make a 405?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
What a rude young man [:(!]

mrbump · Post by **mrbump** » 03 Nov 2004, 00:24

Guys,
Thanks again for the replies!
rg, we could have the same problem here as the gearbox in this car has 200,000 plus miles as well! Gravy WAS the best word to describe the oil, but it has been changed!!
tfurness, what you said rings alot of bells. The engine and gearbox were changed on the car about 10,000 miles ago. Then about 2000 miles ago I noticed the inside edge of the front nearside wheel was badly worn and it turned out to be 3deg negative!!! I thought this had just been because I didnt touch the rack at all when changing the engine, and assumed it would be OK![:(] Maybe this has caused that wheel bearing to fail? I will change the n/s wheelbearing this weekend I think. Gotta be easier than the diff- hasnt it? I was told that you may also need a new 'hub flange' when changing the bearings, anyone know what this is?
thanks again!