De Dion tube

SydneyRoverP6B

SydneyRoverP6B

Well-Known Member
Staff member
The tube in my 1974 3500 is of the grease type. Recalling a phone conversation with a Rover mechanic here in Sydney during the late 1980s, I mentioned to him this fact, to which he replied,..there is no such thing! All tubes are oil filled he said. I said that a friend and fellow 1974 P6B owner's car also featured a grease type de dion. He replied,..oh so there are two of you! Needless to say, I did NOT take my Rover to that business.

I mention the above story as a lead in to my question. Are the majority of cars in the U.K fitted with the oil filled de dion? Was there a specific year in which the grease type were fitted?

The spare parts book lists only one de dion part number, altough it does list the various parts specific to each type. The work shop manuals make no mention of the grease type.

Ron.
 
If it helps I broke up a 1974 year p6 which had a greased tube, spent ages turning it over looking for the filler hole before it finally clicked!

Simon
 
hi on my 1969 v8 that is oil filled but i got a brand new spare one that i was looking to check for oil then i clicked it greased up but would that fit on my just in case anything thing happens
 
I'm pretty sure they were all grease filled 74 onwards but saying that with the age of the cars now they could have either type fitted now

Regards Colin
 
Upside down here in NZ we get our cars road worthy checked every six months
Since my P6b's last 6mth medical the De Dion gaitor/boot gas gone from good condition to absolute mush and oozing oil.
Ive done about 50km in between WOF checks
Any reason why?
 
The one on my car failed quite quickly too, within a few months of passing her MOT. I suspect that the seals go before the gaiter and the oil that is now held back by just the gaiter accelerates it's deterioration. And when it goes you have all that oil gushing out making it look worse than it is.

Here is how I did mine. :)

I popped the car up on ramps, I always jack a car up on them and face them in opposite directions. This gives good height and I feel a good safe platform to work on the car with. I always give the car a good shake before getting under it. After this picture was taken I also jacked the body up a bit and put on axle stands to give me some more room.




As you can see here its leaking, and from what I've been told, if it's leaking then the oil seals will need replacing.



So I ordered up the boot, and two oil seals + gaskets.



I put the jack under the tube and undid the bolts, slowly, was not sure what was going to happen. Turns out not much. With the bolts undone and the jack taking the weight I gave it a tap to split then dropped that end down. Before unbolting mark the two half's as these bolt up in one location and so marking them will make it easier to relocate and align the bolt holes.


Now with it off it's time to strip it down. When you remove these make sure you have an oil tray under when they bolt on as if it's leaking as bad as mine it will poor oil out.


The seal is a little awkward to get out because of this flange, it's pushed onto the end and looks hard to get off and if damaged even harder to replace. As it turns out using a flat nosed screw driver I managed to lever it out without damaging the flange. The other end just has a big washer holding it in that falls out when tour turn it upside down.



Before retracting the inner tube there is this odd clip, you need to remove it or you'll damage the lining that the inner tubes side on.


Of cause I painted it up before fitting the oil seals.


And with it all back together it's looking ready for fitting. :)


And here it is where it belongs. :) I'll paint the rest of the suspension soon, can't do it now as I need the car, the exhaust on my bike has crumbled away, just before the MOT, so that was cancelled. And to top it four of the exhaust studs snapped off. So this will be taking my time up over the next few weeks.
 
I see why a picture is worth a thousand words .
Very helpful -thanks .Will be ordering the seals and rolling up the sleaves
 
What if someone fills an early tube with grease?
I suppose that this will sort out any issues with oil leaks...
 
Thanks for posting those photos, Richard(UK). I just replaced the rubber boot and seals on my Rover 2000TC, that I have here in the US. I have had the parts for a few years. but all my manuals said you had to pretty much dismantle the rear suspension to fix install. Just taking the tube off worked really well. I think I could have even done it without the ramps I borrowed. I will have to do the same to my Rover 2000 automatic the next time I am in Australia. All the tools I needed were a 7/16th inch socket, a flat head screwdriver, some rag to clean, and a bit of gasket goo.
 
Yesterday i replaced the seals and gaiter in more or less the same way as described by Richard. It turned out that the gaiter was fine, but the inner seals were rather hard and useless. Probably they were the factory fitted originals, hense the gaiter was full of oil that was seeping through the right side.

All went well with the usual cleaning and painting that slowed down the whole procedure until it started to getting dark. This is probably why i did not see and forgot to fit the odd spring wire clip inside the inner tube. Needless to say i don't fancy dismantling the tube again to fit this, and i think it does not affect the way the tube functions, BUT can anyone confirm this?

Thanks,

Demetris
 
I "think" it only stops the tube from moving apart too much, but for that to happen something else has to be very broken. Maybe it was there to help during assembly in the factory.
 
I was thinking along the same lines Richard, when the tube is off the car the spring clip prevents it moving too much and stressing the gaiter. However, when on the car it's the halfshafts that dictate the tube's movement.
 
I recently received my gaiter and seals. When I ordered the required fittings, I was told I did not need the paper gaskets, and they were not sent. So... what do I do here? Just apply some RTV sealant or gasket goo to the junctions?
For those using RichardUK's technique, are the ramps just for increased clearance? I have put on some weight, but am able to access all bolts laying on my back. Plus I wouldn't have to worry about car rolling forward or slipping off ramps and jackstands. Comments guys?
Roy
 
Hello Roy,

You can if you wish make your own gaskets, or just apply some sealant of your choice to the de dion - elbow join at each end. It is not impossible that your existing gaskets will come away without falling apart.

On using ramps,..personally I would not do it this way as I don't believe in placing jacks beneath the de dion tube. I have always supported the rear of the car at the jacking points, using car stands supported by solid steel rods. With the rear wheels off the de dion tube can be removed, and refitment is not too difficult. Just make sure that you mark both ends of the de dion to elbow interface with a dash of liquid paper or similar as it expediates refitment....the bolts that secure the de dion are not uniform and from memory are not equidistant either.

I will add that when I have removed a de dion tube, the half shafts had been released from the differential, and this certainly adds to the ease of removal and refitment.

Ron.
 
SydneyRoverP6B said:
On using ramps,..personally I would not do it this way as I don't believe in placing jacks beneath the de dion tube. I have always supported the rear of the car at the jacking points, using car stands supported by solid steel rods. With the rear wheels off the de dion tube can be removed, and refitment is not too difficult. Just make sure that you mark both ends of the de dion to elbow interface with a dash of liquid paper or similar as it expediates refitment....the bolts that secure the de dion are not uniform and from memory are not equidistant either.

I will add that when I have removed a de dion tube, the half shafts had been released from the differential, and this certainly adds to the ease of removal and refitment.

Ron.
Click to expand...

Ron,

I think you'll find that the reason for the trolley jack beneath the tube is so that it won't fall down and damage it as it's being released, in much the same way that you support a gearbox or the diff when removing them. You can't exactly jack a car up on the tube.

The ramps are a nice way of gaining extra clearance, although I tend to drive the car onto them and then brace the front wheels. The SD1 actually came with a brace that slotted against the wheels for just this - and because they tended to slip down ramps quite easily sometimes ;)
 
Rather than start a new thread, I thought I'd bump this one as I have seen that someone else asked the same question that I have and I don't think it got answered

- do grease filled tubes require maintenance, as in a clean out and refill with new grease? I notice that there's no grease nipple so I'm wondering if it's something else I need to look into.
 
ewokracing said:
- do grease filled tubes require maintenance, as in a clean out and refill with new grease? I notice that there's no grease nipple so I'm wondering if it's something else I need to look into.
Click to expand...

No, not as a service item, it was supposedly a sealed for life unit. Probably done by BL for 2 reasons, firstly to reduce the service times by a few microseconds, and secondly to stop the recurring problem of the rubber boots leaking oil when they split. If it gets noisy (or seized) remove and overhaul it, but you would have had to do the same with the early ones.
 
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