Re-bushing the Rear Trailing Suspension Arms-GET THEM DONE!

[Brian]

Vanny wrote:
Oh well, that was probably a waste of time, how exactly do you think the nipple will help? By filling the void with oil, or by lubing the bolt? If you left the plastic tube out then the oil/greese will simply run to the lowest part of the arm and escape, and when the suspension collapses the oil/greese will drag dirt out of the void and into the bearing, thus knackering it faster.

Hi,

I am not quite sure how to answer this, but will give it a shot.

Over 50years ago I purchased a side lever grease gun, and as you know these modern cars are not fitted with grease nipples, let alone imperial ones, and I do like the feeling of pumping the old side lever, gives me some pleasure.

Anyway, thought I would fit some to the rear swinging arms, and you are absolutely correct, it does not work too well. On the first grease injection attempt, it came up to pressure and I cound feel some resistance as the very thin plastic tube resisted, then POOF, it burst oh joy, but the oil grease mixture came out of a hole in the arm that is used to let the sand out after casting, but this was collected and put aside for future valve grinding, I am into recycling you see.

So removed dismantled and rebuilt again using white high pressure water pipe in lieu of the very thin black original type.
This now works a treat, I can get up the max pressure without the tube exploding.

I have also fitted grease nipples to the steering pinion valve bottom plate, this does work well, as you can observe the bellows each end of the rack, I blow these up to about 50% original size.

Oh, and I have recently fitted one to the volume control on the radio cassette player. I am not too happy with the result, as all I seem to receive now is smooth jazz, and I do miss the traditional mainstream type.

Hope this answer is helpful.

Regards

[Kitch]

I have had a situation in the past when a 13mm socket rounded the corners of the head off, then you really have some fun. This approach will minimise the chance of a sheared bolt.

I've done a few, and only once experienced an anti-rollbar bolt that couldn't be persuaded: I always use a 13mm hex-form socket in the first instance before trying any alternative approach, and take the "cracking" and wind-off process as steadily as possible.

Often the risks can be considerably lessened though careful pre-planning and preparation - which goes for the job as a whole. A repeated programme of applying loosener to the bolt area beforehand pays dividends, after wirebrushing the bolt and surround (though getting at the area isn't always easy).

Bash an old 1/2 onto it. Doesn't matter if you can't get it off again...who needs them now? It won't slip at least!

[citronut]

thinking about it it is probably the tolarance in the machineing of the spacers at each end and bearing seats which createor not the preload on the bearings,

the length of the tube will just act as a stop when tightenning the pivot nut and bolt, as the tube should be locked tight between the sub frame lugs, and the rest should be able to move/pivot freely between the sub frame lugs

regards malcolm

[Vanny]

Brian,

Where exactly do you insert the grease nipple? I understand the theory, but conceptually the system does not work. Looking at the Citroen provided cutaway/arrangement diagram;



The green shading represents the void, yellow where the bolt is, and grey is the casting its self.

With the tubing in place, there is no where in the casting where a nipple can be fitted and provide grease to the void between steel tube and plastic insert. Its not an issue of how much pressure is applied, but simply there is an impassable barrier blocking the grease getting to the back of the bearings. Perhaps i should have coloured int he area where the grease is required.

With many members having suggested the idea of fitting a grease nipple in the past, very few have take time to answer my questions about the method, so i appreciate the replies and maybe you might convince me that it is a worth while thing to do!

[cauchoiskev]

With many members having suggested the idea of fitting a grease nipple in the past, very few have take time to answer my questions about the method, so i appreciate the replies and maybe you might convince me that it is a worth while thing to do!

This may be another of my "half thought ideas" , but I can see at least three places where you could put a grease nipple :



I put mine at point 2 (you just drill through the plastic tube) because the other two are not easily accessible for the grease gun, and n° 1 will tend to grease only one side.

[Vanny]

a nipple at 1 will simply burst the end seal and not lube the bearing what so ever so that is right out.

2 and 3 are pretty much the same thing, but how long is the thread on the nipple, how do you ensure the pipe doesnt move? The schematic is just that, it doesn't really show that there is slack between the casting and the plastic pipe, so a seal need to be made between pipe and nipple. If there is no seal then the lube will simply run back into the void.

I guess the pipe doesnt move much if at all being compressed by the bearings (and thus sealing on the races), and the grease wont run too much if the correct grease is used, but i'm still not convinced that giving the grease the potential to not be in the correct place (ie running into void) is better than simply doing the job correctly as the Citroen engineers designed.

And before anyone says it, no i'm not of the age where every tool or machine i started out on had a dozen nipples that had to be topped up, so perhaps i don't appreciate them as well as i could. But my experience of these machines that where built for many lifetimes, is that they where designed with greasing in mind and so have channels and lubing ways built in under the nipple.

[Brian]

Vanny,

Well, I use position No.2 as shown by Cauchoiskev, and only one nipple on the outside of each arm.

If the bearings are in good codition, the nipples can be fitted isitu all as indicated by the late Alan Smith. "Can't find the article, was on Andyspares forum."

If the arms are removed and new bearings, seals, spacers etc are fitted, then fill the void on the inside of the plastic tube "white area on your diagram" with the thickest oil you can get SAE 300 +.

Distance of nipple 30 to 45mm from edge of arm.

Be carefull when locating the nipple postion, to ensure the grease / oil gun will fit onto the nipple, when arms are back on the car.

And to top up slight leakage using the nipple as the oil is required to be in contact with the top of the rollers, and slight pressure using the gun will exit past the dust seals and lubricate these.

I am sure this is the weak part of this design, as it's the most likely area where water ingress will occur, with subsequent bearing distruction.




I have indeed used plastic water pipe in lieu of the thin black original, the size I used just required 1 or 2 turns of plastic tape on the outside ends of the tube to achieve a good seal.

Found Alan's the thread, but not the pictures..

Regards



I've just fitted grease nipples in-situ into the rear swing arms of the suspension on the BX.
Although they show the fitting to a BX, they would also apply to CX and GS as well as possibly other hydraulic type Cits and possibly Pugs.
Can't speak for sure about Pugs as I don't know for sure the type of rear suspension they have fitted but possibly it could incorporate something similar.
Cits with this type of system on them require the bearings and spacers to be fitted as a kit every few years particularly in a wet or snowy climate.
This almost eliminates the job provided that the owner gives thewm a bit of a pump of grease every year or so.
The dimension for fitting the grease nipples is approx 30 - 35mm from the outer edge of the arm and central in the area using the bolt which passes
through as the "target" in determining the central location.

Alan S.


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