de dion failure

[arthuy]

Hi All,

I had a bit of a fright today, when I suffered the old shearing off at the trailling arm at the De Dion.

I had been on the motorway and was heading back towards it to go home when it happened. I thought a wheel had came off and expected to see it roll by the window.

I can get a second had item but am interested to hear other views.

Jr wadhams do recon items are these any better than good secondhand?

Also is it always the drivers side that goes or can it happen to both.

Cheers
Arthuy

 

[Rubythursday]

Mine went at 70 on the motorway, managed to get it to the hard sholder in a series of sparks whick wore away most of the end of the trailing arm!

It was the passenger side, didn't look particularly rusty, looked more like metal fatigue.

 

[ianp6man]

hi,
i generally find it is the driver's side that goes. ( that is what i get asked for more than the passenger side ) but they do go on both sides. J.R. WADHAMS re-conditioned ones are from cars in australia and places like that, so don't see much rust on them if any.

ian

 

[arthuy]

Thanks Ian,

Is there anything that especially causes the trailing arm mount to shear off or is it just old age? would want to avoid this happening again.

Arthuy

 

[webmaster]

If possible could somebody post a photo of a failed joint.

It might be possible to add some additional metal into the affected area to prevent them ever failing.

i.e. if its just a slightly weak design ( we are talking a good 30 years of service after all ) Then maybe a simple fillet, or additional plate welded in would make them strong enough, or prevent any flexing which might cause failure.

Richard

 

[Rubythursday]

I reinforced mine, there is a strengthening washer about the size of a 2p spot welded on in three places, I removed the washer and fabricated a larger plate and welded it back on. I'll crawl under the car sometime and take a pic.

 

[arthuy]

Hi All,

I will post a picture of the failed mounting as soon as my new card reader arrives.

I fancy the ideal of adding strength, I have heard these tubes can rot and collapse but for the mountings to shear off with out warning is a bit of a fright.

When I get my new one I would like to strengthen it up. Has anyone else done somthing like this.

Arthuy

 

[young_simon]

I've had all my suspension arms and both elbows shotblasted and powder coated by a local company for about a tenner per part. Before I had them done I gave everything a good wire brust to check it over, and it all looked okay. The car was on the road for only 8 years from new so it hasn't had the full 30 years of abuse that most would have had. I'll be using my car on the motorway everyday so I'll be taking no chances.

I can see the most likely reason for the fatigue cracks to come from the pitting of the steel as it rusts, so if you can do anything to slow the rust or stop it entirely, its better than nothing. If rust does start coming out from behind the reinforcing washer on my elbows I'll cut them off and weld on something bigger and more suitable as soon as possible. Has anyone ever considered galvanising the elbows?

As far as I am concerned, a small patch of rust will grow, and once it is between two bits of sealed metal, you've had it. One of the planes I work on was resprayed about this time last year, and within six months the corrosion was bubbling out from the seams in the same places as before, the only cure was to ruin the paint and split the seams to clean it up properly.

 

[eliseman]

many years ago I had the lower ball joint drop out from the bottom of the o/s swivel pillar on my Dads 2200TC. I was turning around in a golf club car park at the time.

As a result the pillar pushed back onto the bulkhead locking the road wheel. The frightening thing was just 2 minutes earlier I was doing 80 mph down the local dual carriageway.
Lucky escape or what.

Returning to the subject in hand I am very sorry to learn of this frightening failure. Unfortunately as time drags on these cars are likely to suffer more and more obscure failures which Rover, at the time of designing the car, could not have possible considered.

Remember, the youngest P6 is now 28 years old, God that is unreal !!!!

 

[arthuy]

Hi Eliseman,

Quite right about the old age thing.

My Car has had a hard life towing and mine is a spring chicken at 27 years old. failure can happen at any time.

Arthuy

 

[BBLongman]

I've just stripped my de-dion tube and elbows for painting and thought you might be interested in my observations. The elbows on the car were re-conditioned items which had been blasted and powder coated.

A lot of the powder coating had been lifted by rust which I suppose is to be expected after 5 years but it was the inside of the elbows that you can see after unbolting from the tube that was the most shocking. It was absolutly thick with rust inside and I mean the kind of rust you might find on a bit of steel kicking round of a beach. The grit blasting had only cleaned the first two inches of the tube and the rusty section had never been touched.

I've re-stripped my elbows in caustic and de-rusted in a phosphoric tank. It took about 2 days to get the rust out of the elbow and I had to chip stubborn bits off with a chisel!

If you fit a re-con elbow take a look inside first. If it's not up to scratch get them to change it. P6 spares suppliers charge a decent enough price and so should carry out more than just a cosmetic restoration. Blasting and powder coating the elbows will be costing the no more than £20 each and probably a lot less if they're done in bulk.

 

[BBLongman]

Just spoke to Jeff at R.Weekley spares about the elbows and he said that they were actually chemically de-rusting their elbows before painting. He also says he has some elbows coming over from cyprus in the near future which will be like new due to the climate. Could be worth getting hold of some while they are available and giving them a thorough rust proofing.

 

[arthuy]

Hi All,

Just to update this thread.

After a long hard think I bought a second hand elbow and had a friend gas weld some strengthening plates in to both my elbow.

I order to preserve and protect them I had both on the the De Dion elbows Galvanised. Yes dipping in molten Zinc and boy do they look good and they will probably out live the car.

I can highly recommend this process and now any fears I had of a the De Dion giving way are long gone.

I have a few picture which I have also sent to the editor so they may end up in the p6 news if the Met police car is out of action over the next few months. LOL

A few pictures below. I am not sure how long they are available for.

Colin

Edited By arthuy on 1197825455

 

[Phil Robson]

Hi There,

Same thing happened to me (driver's side) & I recounted the tale in the magazine 3 or so years back.

I replaced both elbows & noticed an arc of nothingness (ie: a hole) above the nearside washer/stiffener after I had cleaned it up, so how long that would have lasted is anyone's guess.

From examination, I would suspect rust is the main culprit rather than fatigue (most of the broken edge was thin & dark as opposed to thick bright metal).

What you've got to bear in mind is that a P6's rear suspension works in reverse! The weight of the back end is supported only by the bottom link/de-dion elbow joint & the car is pushing this apart all the time, as opposed to sitting 'on top' of the wheels.

I do check my car regularly since it collapsed & would advise all owners to do the same. If it's any consolation, I was told that this sort of problem usually occurs where there are undulations, rather than smooth roads where the vertical forces are not so acute. Just try to avoid it happening anywhere!

Finally, I do remember at least 3 cars in the 70's losing front wheels due to front bottom links giving way - but nothing since, fortunately!

Phil (East Yorks RO)