With reference to the rear arm bearings on the BX and CX (same part numbers) I recently replaced one set and have another ready to go. In the process, some differences were noted which needed explaining but the explanations didn't seem to make sense; however, I've been talking to an engineer/Cit enthusiast today and found some interesting facts I thought I'd share.
Firstly, the SKF part number shown on the original ones and the part number on the ones I got were different. Not only were they different, but they were also different to the ones I had previously been quoted as they had been "updated" but why????????
It seems that PSA gave SKF the flick about 7 years ago as their main supplier and in the process, came to some arrangement that stopped them from selling bearings (over the counter) that had been made for a specific purpose for Pugs or Cits, thereby giving dealers the exclusive rights to those parts and thereby a monopoly on supply & therefore price.
We are "reading between the lines" here, but it would appear that in an endeavour to supply a market that existed, they then set about producing "similar" bearings under different numbers.
I do know that the box mine came in had the word "citroen" in very small print a' la "citroen" so it was not obvious, but again as the time frame was 7 years, it could be a Statute of Limitations thing which is normally 7 years, hence it could be that whatever restriction was placed on them expired at the end of a 7 year period.
The other piece of info, on the same subject was also interesting; I was of the opinion that as my original bearings were contained in a steel cage and the new in plastic, that there was a difference in quality. Not so apparently.
Tapered roller bearings are more often used in a situation where higher speeds are required than those found in rear arm bearings and this explains the difference in manufacture.
Citroen in the past used bearings like my originals of all steel. They then went into ones using brass cages.
The problems when used in higher speed situations and to a lesser extent in these, is that the bearings can & often do get grit into the operating region and this when jammed between the roller and the cage as an abrasive creates havoc by grinding into both the cone and the rollers. In the case of the brass cages, it often caused the cage to collapse which in turn caused the rollers to eventually touch each other and grind the entire thing into a munched up mess.
Modern technology and modern plastice mean that as the cage plays no other role than locating the rollers, that if a spec of grit or a sliver of metal is to get onto a roller, it embeds itself into the plastic and there it stays; so rather than plastic cages being a cheaper option, they are actually designed that way to give the arm bearings greater life.
As an aside, my engineer friend also had a set of "Timken" bearings that also are compatable for CX & BX rear arms but come as two separate identities; the outer cone and the actual race. I'll get the numbers off him when I next contact him so we also have another option in case the supply from Mr SKF dries up.
Hope this can be kept for future reference by anyone into maintaining their BXs and CXs to avoid unwarranted expense in this job.
I'll drop this post into the archives so I can attch more info to it as regards the job in general.
Alan S
__________________
Firstly, the SKF part number shown on the original ones and the part number on the ones I got were different. Not only were they different, but they were also different to the ones I had previously been quoted as they had been "updated" but why????????
It seems that PSA gave SKF the flick about 7 years ago as their main supplier and in the process, came to some arrangement that stopped them from selling bearings (over the counter) that had been made for a specific purpose for Pugs or Cits, thereby giving dealers the exclusive rights to those parts and thereby a monopoly on supply & therefore price.
We are "reading between the lines" here, but it would appear that in an endeavour to supply a market that existed, they then set about producing "similar" bearings under different numbers.
I do know that the box mine came in had the word "citroen" in very small print a' la "citroen" so it was not obvious, but again as the time frame was 7 years, it could be a Statute of Limitations thing which is normally 7 years, hence it could be that whatever restriction was placed on them expired at the end of a 7 year period.
The other piece of info, on the same subject was also interesting; I was of the opinion that as my original bearings were contained in a steel cage and the new in plastic, that there was a difference in quality. Not so apparently.
Tapered roller bearings are more often used in a situation where higher speeds are required than those found in rear arm bearings and this explains the difference in manufacture.
Citroen in the past used bearings like my originals of all steel. They then went into ones using brass cages.
The problems when used in higher speed situations and to a lesser extent in these, is that the bearings can & often do get grit into the operating region and this when jammed between the roller and the cage as an abrasive creates havoc by grinding into both the cone and the rollers. In the case of the brass cages, it often caused the cage to collapse which in turn caused the rollers to eventually touch each other and grind the entire thing into a munched up mess.
Modern technology and modern plastice mean that as the cage plays no other role than locating the rollers, that if a spec of grit or a sliver of metal is to get onto a roller, it embeds itself into the plastic and there it stays; so rather than plastic cages being a cheaper option, they are actually designed that way to give the arm bearings greater life.
As an aside, my engineer friend also had a set of "Timken" bearings that also are compatable for CX & BX rear arms but come as two separate identities; the outer cone and the actual race. I'll get the numbers off him when I next contact him so we also have another option in case the supply from Mr SKF dries up.
Hope this can be kept for future reference by anyone into maintaining their BXs and CXs to avoid unwarranted expense in this job.
I'll drop this post into the archives so I can attch more info to it as regards the job in general.
Alan S
__________________