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

[Turboalternator]

Just a quick post to let everyone know that you can have your trailing arm "bushes" redone at a very reasonable price.

This applies to members living in London or to the North/West/East of London.

Finding someone to do the job can be quite a big undertaking, as many of you will know.

You will need to acquire a repair kit which consists of the following:

1 No. long bolt
1 No. steel sleeve
1 No. plastic sleeve
1 No. lock nut
1 No. lock nut washer
2 No. bearings
2 No. steel end caps
2 No. oil/grease seals

Other than the kit you will also need:

Hydraulic seal for the brake pipe

Once you have got the kit and seal call Philip on 0208 997 6693. (RS Autotech Ltd). Situated in Perivale, (Ealing), North London.

He will do the job for you for £85. (Labour cost for each arm). However, for that price there are certain conditions that need to be met:

1. Everything must come out relatively easily. The two bolts holding down the clamp holding down the anti-roll bar are the worrying ones - although they are quite fat in diameter. (Philip will not take responsibility if these bolts shear off due to being rusted through).

2. Philip does not do any hydraulics. To do the re-bushing job, the rear brake pipe has to be removed from the rear brake caliper and you must ensure that it can be unscrewed without damage before you go to Philip. (Just unscrew it a few turns then tighten it back - do not remove or you will need a new seal). The same goes for the bleed nipple. Also, if your brake pipe is very old and liable to break with slight movement you will need to have the pipe replaced before you go to Philip. (These pipes are still available or at least were a couple of months ago).

Failure of this arm bush is a definite MOT failure, as I can personally testify. If you intend keeping your BX for any length of time I would recommend that you have the rear trailing arms rebushed, as soon as possible.

Furthermore, in my case the bearings had literally disintegrated! My rear tyre was rubbing against the bodywork.

It is possible to do the job yourself but it is difficult because you will need a good work bench with a good vice to do it. Removing the arm is not that bad but doing it "on the ground" will give you a lot of grief and you will need axle stands.

One final point: It is becoming increasingly difficult to find one garage that will carry out all the various jobs that need to be done on a BX. I think that members should post the name of a garage that has just done one particular job for them. That way a "specialist" register can be started and populated.

For the first entry: Philip of RS Autotech Ltd .. Specialist in: Rebushing rear trailing arms.

No "smart alec" comments or posts please .. yes one knows how "easy it is to do this job". (Actually, it is not that easy and is finicky as I witnessed the job being done). This post is meant for those of us who cannot do it for themselves or do not have the facilities to do the job.

Best regards to all,

[Kevin B]

Just a few points to bear in mind that you have not mentioned here.

The rear arm bearing repair kit that you usually get from GSF or Euro car parts does not come with the adjusment shims that are required to get the correct preload on the taper roller bearings.
These are available from Citroen, but like any other OEM part are not cheap.

You do not mention if new shims are being fitted, or the old one being reused?, does this garage do a dummy build on the swinging arm to check if bearing preload is correct (I doubt it), without this the bearing could have too litle or too much preload either of these conditions is severely life limiting for taper roller bearings.

[Turboalternator]

Hallo Kevin!

If by shims you mean a variable spacer washer to be located between one of the steel end caps and the bearing face, (thrust), then no -- none were fitted. But, as far as I could see, there weren't any shims in the original build either. And I have had my car since new and that offside arm was never rebuilt.

I very carefully examined what came out and there was a lot of dust and the bearings, (seats), had disintegrated. No sign of shims though.

Realistically, I don't think that any normal garage would have the facilities to carry out the test that you mentioned. I had a great deal of trouble just getting one to do the job without any elaboration.

Thinking about it, you may be right and the life of the bearing may be shorter --- but having said that --- the part that I bought was a SKF kit and it may well be that they have improved manufacturing tolerances to a great extent, (CNC manufacturing etc), and that fact, (improved manufacturing tolerances), coupled with the fact that the bearings are high quality thrust bearings may mean that very little damage will occur with the absence of shims. Could that be the case do you think?

By the way, I do realise that it is the variation of the length between indents, (bearing location), in the arm itself that may be the root of the problem, requiring shims to meet the demands of axial lateral forces. But what I mean is that the kit itself also contributes to the overall loss of accuracy, (especially a kit manufactured with poor tolerances).

So if a good "average" for the arm dimensions is assumed, (between indents), then that might mean that shims may not be necessary if a repair kit with very good tolerances equiped with good quality thrust bearings, (able to bear and endure a little play), is used.

As far as my car is concerned, the nearside arm was rebushed without shims in January 2004 and is still OK. About 30K miles now. So really if this refurb lasts 40 -50K miles then that is good enough for me. (given the total cost of having it done = £85 + £35 for the kit).

I'd be interest to hear your further comments and anyone else's.

Best regards,

[MULLEY]

I've never even heard of doing a dry run 1st by trying various pre-loading, that must take bleedin hours & isnt it virtually impossible to get it all apart again as everything is so damned tight???

All of the arms that have come off my cars have never had a washer on them, perhaps they were converted to dust? Mat did fit a middle sized washer to my tzd to hopefully be somewhere in the middle of either too little or too much pre-load which i guess is better than being even further out without?

Perhaps the more knowledgeable can expand on what they've tried or recommend?

[Vanny]

WOW, now thats expensive, and i dont think i would take my car to someone who doesn't understand the system. Disconnecting the brake line causes more hassle than is worth, and makes me wonder how skilled this guy is. Well precticed the job takes 1.5 to 2 hours (30 minutes per side plus 15 minutes changing the bearing, plus faffage), thats assuming you have the correct tools (as i do) and not bothering with the pre load washer. I used to charge around £60 a side. Oh and that was before i had a rattle gun.

The shiming process is lengthy and i have gone down that route before. It is impossible to complete the task without the correct tool (which i do have, but it is the only one i have ever seen), and having compared doing the job with and without the shims, there is little difference if the bolt is torqued up correctly.

Mulley, the 'dry run' only involves slipping the bolt back and adding a shim then torquing bak up, not pulling the bearings back out! I have also never seen a Mk2 with a shim, but then i doubt i have ever done the first bearing change during any BXs life.

The only real advise over the usual is a recent suggestion to use high quality hub greese as fitted to land rover defenders, much thicker, higher quality bearing greese. I've not done it myself but will do next time. Can be obtained from Paddocks, Cradocks or LR Super market.

[Kevin B]

The aftermarket rebuild kit for the swinging arm as far as I know has only ever being made by SKF, and they never come with shims.

Whilst it is true these components will be made to high degree of accuracy, there will still be a stack up of tolerance errors when the whole item is assembled, hence the use of a shim. I too have stripped these swing arms down for a rebuild and no shim was present. However I did need a shim when I put it back together.

I have done more of these than I care to remember, and brake pipe removal is not required, just remove the complete caliper assy complete with brake line and tie in a suitable temporary location until you put the swing arm back on the car.

I have not got any specialist tools either, although I have made a few bits and peices. Particuarly for removing the outer taper roller tracks from the arm, as this aspect of the job can turn out to be a real pain!

By carrying out a dummy build you are giving the swing arm bearings the best chance of a long life. I merely assemble the swing arm less the seals. Then using an old swingarm nut and bolt plus some really heavy duty washers (that I specially machined for this purpose), torque it all up together. By rotating the bolt by hand you can get a good feel for the bearing preload, admitted this process is very dependant upon the skill of person doing the job. If you just slap it together with the seals in situ the drag from the lip of the seals can often give you the impression of having the correct preload. The dummy build doesnt take that long, certainly a lot less time than stripping a swing arm out again in a few months time.

When your happy with the results of the dummy build dismantle the swing arm and refit, this time with the seals and loads of grease on the bearings and seals.

Plieades rebuild swingarms themselves and they use gearbox oil instead of grease, and they said the bearing life expectancy is much greater, I am going to try this myself on the next one I refurbish myself.

One final point, when removing the anti roll bar, I always give the 13mm bolt heads a good smack with a sizable drift before removal, and I also drive on a 1/2" socket onto the head of the bolt, as 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.

[RxBX]

Excellent write-up 'Kevin B'

One final point, when removing the anti roll bar, I always give the 13mm bolt heads a good smack with a sizable drift before removal, and I also drive on a 1/2" socket onto the head of the bolt, as 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 minimize the chance of a sheared bolt.

Also when tackling these Anti-Roll bar clamp bolts NEVER use a Bi-hex socket as this also tends to chew the corners off ALWAYS use a good tight hexagon form socket on these particular bolts

[mat_fenwick]

Interesting stuff…I've only done Mk2s, and not many, but all of them up to now have had a (usually mangled) shim in place. They had been untouched since the factory. What I have always done when replacing shim adjusted bearings of any type is simply reuse (or replace with an identical size) the existing shim, obviously checking for play or tightness on re-assembly.
Some years ago I asked the advice of a bearing design engineer, who told me that in an ideal world you would check the preload when replacing bearings, but that the tolerances in the bearing housing are likely to be many times greater than those of the bearings themselves, i.e. the shims compensate for housing variations rather than bearing variations.
When checking the preload I can't see any way of doing it without the metal tube, I take it you basically need everything bar the seals?
One last thing - on the ones I did for Mulley the O/S had been done recently and filled with a very runny grease. Admittedly the car had been stood for a couple of years, but the top of each bearing was pitted with heavy rust from lack of lubrication.

[DLM]

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).

[Vanny]

Dont confuse the washer that comes in the SKF kit with the shims that citroen supply. The washer is a nominal thickness to make up for the loss for the correct shims.

Gear oil is too thin and will likely just make its way into the arm or out through the bearing. Also, isn't gear oil corrosive to plastics? This the oil will just escape into the void. I would have thought a fully synthetic engine oil would be better? Still if simple oil was the solution then why does the kit come with greese and why do the LR off roading comunity swear by using the correct greese when trying to reduce water penetration?

I'm not sure i fully understand this dry run assembly thing, it just sounds like your tightening up the bearings into there races, which surely is what one would do when fitting the bearings in the vice?

The two reasons the bearings fail is a) water penetration b) lack of roller movement within the bearing (often caused by a). Its the lack of roller rotation that wears the bottom of the bearing out and eventually kills the bearing and the housing and causes the creaking. I can see a half turn of the bearing every year being very beneficial!

I personally have never had a problem with the ARB bolts, the 10mm deep head seem perfect for easy removal when a good quality socket is used?

[citronut]

it is the factory machineing of the arm/bearing seats and the acuracy of the pivot tube (steel centre tube) which creates a need for a shim,

the dealer sells these shims in an assorted packet, i buy a packet and re/fit as close to the original as possible,

i also run two short beads of mig at opposit sides of each bearing inner race, this firstly gives you something to droft the race out by, and secondly the heat sometimes allows the race to just drop out,

i also just leave the calliper attached to the pipe

i only charge 60 quid as long as nout is siezed, which in my experiance have only ever had one which every thing was stuck solid, so loads of fun had by all

regards malcolm

[cauchoiskev]

On the last pair of rear arms I did the shims were missing (as was one of the plastic tubes).

I find the the cost of the shims is ludicrous, so I put everything together then measured the height of the steel tube above the thrust bearing on one side, with the other side perfectly flush.

I then took it apart ground down the steel steel tube so that it would be flush on both sides when assembled (there was only about 0.3mm to come off). Works fine so far, cost nowt.

[citronut]

cauchoiskev wrote
"I then took it apart ground down the steel steel tube"

surely if you grind the tube down at all it will not be clamped tight between the arm mountting points on the sub frame, instead the arm will be directly against the inside face's of the mountting lugs

regards malcolm

[Brian]

Citronut Wrote:
surely if you grind the tube down at all it will not be clamped tight between the arm mountting points on the sub frame, instead the arm will be directly against the inside face's of the mountting lugs.


Interesting point, but I am sure there will be enough flex in the sub frame flanges to take up a few thou.

But those folk that have to use knife and fork techniques would not be able to grind the tube end square

I have replaced 3 car sets of bearings so far, and all had the thin spacer in tact, which was re used. Also in all cases I filled the void with gearbox oil and grease mix, and introduced a grease nipple to enable a top up of oil. All are still going after many thousands of miles.

[Vanny]

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.

I think i will alwasy be of the view that the correct method is the best method when it comes to extending bearing life! All the half thought idea's i've seen so far seem to be a waste of time.