What is this Bearing For?
#16
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I have a new one around here, but can't seem to locate it. However, I am certain that the holes are the same size. Also, the holes in the ones I repaired, and Ed's, were/are not just oversized, but elongated in an odd direction.
And, No, Ed. The pins or studs that the roller body mounts on were not worn at all. I think that is because they are hardened steel and the roller body is cast iron, which is much softer. No, I didn't see any evidence of significant metal shavings, or even iron dust, but I don't think that means much. I cleaned the areas that I was working on before I started.
And, No, Ed. The pins or studs that the roller body mounts on were not worn at all. I think that is because they are hardened steel and the roller body is cast iron, which is much softer. No, I didn't see any evidence of significant metal shavings, or even iron dust, but I don't think that means much. I cleaned the areas that I was working on before I started.
#17
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The elongated hole is a design feature, not wear.
#18
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Jerry, did you inspect the pins for wear? I don't remember for sure if I did (it was 3½ years ago). But I'm almost sure I would have noticed filings or other signs of extreme wear (aside from the elongated hole) if there were any.
I was under the impression that these rollers are rarely if ever touched by the belt. Given the condition of the bearings on mine before I replaced them (IIRC, one of them was either frozen or nearly frozen, yet I didn't see evidence of the roller surface being polished by the belt), I suspect they weren't even touched. That's not to say that the whole assembly might not shake around anyway.![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
I believe some people who installed PKsn'r tensioners just remove these rollers. I didn't know that at the time.
I was under the impression that these rollers are rarely if ever touched by the belt. Given the condition of the bearings on mine before I replaced them (IIRC, one of them was either frozen or nearly frozen, yet I didn't see evidence of the roller surface being polished by the belt), I suspect they weren't even touched. That's not to say that the whole assembly might not shake around anyway.
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
I believe some people who installed PKsn'r tensioners just remove these rollers. I didn't know that at the time.
Furthermore all the rollers were rusty - clearly the belt had never touched them. Despite the apparent redundancy of these rollers I fitted new bearings and refitted them.
#19
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New roller:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20928%20105%20067%2001%203-2-14.jpg)
Mounting pins on the girdle are 7.95 mm OD:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20mounting%20post%20in%20girdle%207-95%20mm%20diameter%203-2-14.jpg)
Driver's side hole in roller is oblong, 8 x 9 mm:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20mounting%20holes%203-2-14.jpg)
Width:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20DS%20hole%20width%20point%20357%20in%203-2-14.jpg)
Height:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20928%20105%20067%2001%203-2-14.jpg)
Mounting pins on the girdle are 7.95 mm OD:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20mounting%20post%20in%20girdle%207-95%20mm%20diameter%203-2-14.jpg)
Driver's side hole in roller is oblong, 8 x 9 mm:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20mounting%20holes%203-2-14.jpg)
Width:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20DS%20hole%20width%20point%20357%20in%203-2-14.jpg)
Height:
![](https://webfiles.uci.edu/redwards/public/Timing%20belt%20lower%20idler%20assembly%20DS%20hole%20height%20point%20308%20in%203-2-14.jpg)
#21
Chronic Tool Dropper
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For those playiong along at home, bearings have some standards among the industry. In Nicole's example, the root "6201" number definnes the OD, ID and width of the bearing. The letters and numbers after that define the seals, shields, and the type of lubrication used. There are other designators that define the precision and finish of the ***** and races, special speed ratings, etc.