Diferences between trail arm kits

[yoseff]

I'm on the market for a trail arm bearing kit , and i've seen some distinct prices between brands, sometimes going twice the value.(In Citroen it was a "small fortune", and i dont know if they still have it )

https://www.mister-auto.pt/gv/jogo-de-r ... /c5/15930/
Locally, from Febi, i can get it for around 70€, if i well remember.

Could anyone put a bit more light on the subject? I know that some people just buy the bearings from SKF, but i cant find the references , and it may be better to have a full kit to change in case mere things are ruined.

I'm thinking to get a Metalcaucho https://www.mister-auto.pt/jogo-de-repa ... cho/05098/ , as in the past i got good results with their parts.

On the change of the bearings , i'm also thinking to add some lubrication points , so i can prevent this problem in the future. Did anyone tried this that want to share some tips on how to do the best way?
This is what i'm thinking to use:

Did mention this in my ongoing topic (https://www.frenchcarforum.co.uk/forum/ ... 0&start=45) , but i think it may be useful that this info is alone on this great forum for others to access in the future.

[aspire_helen]

I fully investigated this a couple of years ago and bought a couple of kits. I even bought an old arm from a scrappy to practice on. In the end, I was lucky enough to buy a pair of cheap old stock Citroen arms which come with bearings fitted. Dealers did not change bearings - it was quicker (and overall cheaper) for them to replace the arm even though a new hub was also required. The problem is that the taper roller bearings have to be pre-loaded on the bench using a shim behind one of the bearings (either one will do) #8 on the diagram. Part 514327 is a pack of possible shims to choose "Thickness Wedges Set"(30mm OD, 22mm ID). The aftermarket kits do NOT provide shims. Citroen use a special jig to precisely measure each arm and its bearings to determine the precise thickness of the shim. This is needed to accommodate machining tolerance on the mating parts ie bearing races, spacer tube, machined faces in the arms. If the shim is too thick, the bearings will be crushed when the pivot bolt is torqued down in the subframe. Too thin and the bearing will be loose. Without the correct jig, it becomes one hell of a trial and error task! However, recovering and re-using the original shim may be a near approximation. You wont know until you torque the the pivot bolt. By the way, the arm is heavy and a very awkward shape to manipulate back into the subframe. I had to grind some chamfers on the subframe to help guide the arm back in.
Regarding the grease nipples. I researched them as well, but because I replaced the arms, I devised a plan to install them to fitted arms. But I have not done so because the car has to be elevated for access - axle stands wont do. So, fit them into the bare arm before fitting the new parts. Give some thought to their orientation and accessibility when the arms are re-fitted. In addition, remember the grease will spread uniformly with the internal space and will only force its way through the rollers once it has filled all other spaces. It is likely that the plastic spacer tube will be filled with the grease. Position them wrong and you will fill the entire hollow arm with grease!

[yoseff]

I fully investigated this a couple of years ago and bought a couple of kits. I even bought an old arm from a scrappy to practice on. In the end, I was lucky enough to buy a pair of cheap old stock Citroen arms which come with bearings fitted. Dealers did not change bearings - it was quicker (and overall cheaper) for them to replace the arm even though a new hub was also required. The problem is that the taper roller bearings have to be pre-loaded on the bench using a shim behind one of the bearings (either one will do) #8 on the diagram. Part 514327 is a pack of possible shims to choose "Thickness Wedges Set"(30mm OD, 22mm ID). The aftermarket kits do NOT provide shims. Citroen use a special jig to precisely measure each arm and its bearings to determine the precise thickness of the shim. This is needed to accommodate machining tolerance on the mating parts ie bearing races, spacer tube, machined faces in the arms. If the shim is too thick, the bearings will be crushed when the pivot bolt is torqued down in the subframe. Too thin and the bearing will be loose. Without the correct jig, it becomes one hell of a trial and error task! However, recovering and re-using the original shim may be a near approximation. You wont know until you torque the the pivot bolt. By the way, the arm is heavy and a very awkward shape to manipulate back into the subframe. I had to grind some chamfers on the subframe to help guide the arm back in.
Regarding the grease nipples. I researched them as well, but because I replaced the arms, I devised a plan to install them to fitted arms. But I have not done so because the car has to be elevated for access - axle stands wont do. So, fit them into the bare arm before fitting the new parts. Give some thought to their orientation and accessibility when the arms are re-fitted. In addition, remember the grease will spread uniformly with the internal space and will only force its way through the rollers once it has filled all other spaces. It is likely that the plastic spacer tube will be filled with the grease. Position them wrong and you will fill the entire hollow arm with grease!

Thanks for your sharing about the diferences in these kits. It makes sense what you explained , and that can also explain why some bearings last more than others (also different materials & tolerances).
I'm not sure if i had the original ones in my 2.2, but they were in a disgrace condition. Fitted some aftermarket kit (Spanish manufacturer) and used a lot of good graphite grease. Hope they last quite a good time.
The grease niples , i also quit the idea, once seeing how it really works inside. It is definitely not easy to do it properly.

One thing i want to do now with more time is to find the references and suppliers for SKF bearings , as it may be one of the best choices for longevity on the arm bearings.

Any good quality kit you can recommend, @aspire_helen?

[aspire_helen]

Honestly, I dont believe bearing quality has much to do with it. Even quality bearings will wear quickly if not adjusted properly or inadequately sealed. It is the overall design which is poor. As the arm moves through only 5 to 10 degrees, up an down, it acts like a pump and slowly but surely pumps grease out. Taper roller bearings (TRB) are the worse than plain rollers or balls (eg wheel bearings), because the sloping faces of the rollers help direct the grease coaxially away from its own rollers. The arm pivots should have grease points, and there should be a service routine to pump grease through the bearings periodically.
For instance, on my BMW motorbike, the TRBs in the swinging arm pivot have a grease point. The wheels and steering head also employ TRBs - both of those are easily dismantled for periodic re-greasing.
The official Citroen arms (with bearings factory fitted) which I fitted showed grease leakage passed the outer seals within 10,000miles. Furthermore, if the taper roller bearings are slightly loose, the outer race of the bearing will distort the lips of the outer seal, slowly allowing grease out and water in.
If you need to replace the bearings again, you may wish to re-consider installing grease nipples, even if it takes lots of grease to fill the axle volume first. I wish I had. I can just picture the new grease oozing out of the seals!!