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Valve adjusting shims, ? about identification numbers
I need to buy some valve adjusting shims. The shims have numbers on the side of them (very hard to see, need good glasses and a flashlight or 18 year old eyes) I will reference two shims with 238 and 239 on them. I believe that to be 2.38mm and 2.39mm but my measurements show that they are slightly different than that. For example, 2.38 mm translates to 0.0937". But my measuring works out to 0.097" for the 238 shim. 239 measures out to 0.098. Any help here is appreciated.
Thanks Roger |
The part numbers don't seem to correspond to dimensions.
https://parts.subaru.com/a/Subaru_20...10-012-01.html |
Here is some more info from a little while back.. According to @celek they're sold in .02mm increments which wouldn't jive with your assumption/measurements.
https://www.ft86club.com/forums/showthread.php?t=114499 This is what my manual shows for adjustments.. kind of surprised at the lack of information regarding thicknesses and part numbers.. I feel like most manuals (Toyota at least) will list out different part numbers to be ordered.. https://lh3.googleusercontent.com/bH...=w1613-h523-no |
https://parts.subaru.com/p/Subaru_20...3218AL230.html
Just an educated guess (my background is aircraft technical writing). The parent-Part Number: 13218AL230 sounds like it may have children-part numbers ending in L231 thru L239 (since the parent-P/N's increase by 10's, so L230, L240, etc). I'd guess there are parts with 231 thru 239 based on 9 of the 10 illustrated pictures (the color picture doesn't do any justice though). It's possible that L231 thru L239 could be sourced from multiple businesses (not a controlled source), so potentially any combination could work. So whatever is printed on the shim valves (238 and 239 in your case) may just confirm they can be used together. Or, 238 and 239 could just be improved revisions to 230, like cheaper for the manufacturer to produce, stronger material, etc. Your measurements of 0.097 inch (2.4638 mm) and 0.098 inch (2.4892 mm) may allow for a tolerance of ±0.001 inch (0.0254 mm). To my semi-trained eye, those are realistic measurements of the "same parts." Tighter tolerances are more common on space and flight hardware. Just my two-cents, feel free to to correct me where needed. |
Shims are ground to closer tolerance than .001. A shim measuring. 001 bigger or smaller will have a different part number
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What does the T value stand for? For example:
P/N 13218AL280 shows T = 2.38, and P/N 13218AL290 shows T = 2.39 |
Quote:
[ame]https://www.youtube.com/watch?v=-KGUKji-1A8[/ame] |
T might be thickness
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Ok, so I have it figured out. I knew the shims came in .02mm increments. They start around .070" or 1.80mm. Then go up from there. There are a few shims that come in .01mm increments. But most all are .02mm increments
So, the 239 number on the shim I mentioned in my first post represents 2.39mm shim thickness. That translates to .09409" thick or rounded up to .095" thickness. 2.39mm/25.4=.09409" or rounded up to .095" (95 thousands of an inch) A shim with 219 on it is a 2.19mm thick shim or .086" thick (86 thousands of an inch) shim 2.19mm/25.4=.0862" or rounded down to .086" The shims start at a number of 180 and go up by 02 each time 180 shim=1.80mm 182 shim=1.82mm 184 shim=1.84mm 186 shim=1.86mm and so on So where I was confused (mentioned in the first post) by the 239 on one of my shims and the overall length of that shim (lash cap) of .238" had no relation one to the other at all. Let me explain as best I can. If you measure the total length of the shim, it comes in around .238". That's the part that was throwing me off. The shim thickness which is the top portion of the lash cap is determined by the number etched on the side of the lash cap (shim). In this case 239, which translates to 2.39mm or .095" thick represents the shim thickness. The portion of the lash cap that slips down over the outside of the valve stem has a depth of .143" or 3.632mm. Add this to the top of the lash cap thickness 0f 2.39mm or .095") the total length comes to 6.02mm or .238 rounded up. So I was trying to correlate the etched shim number of 239 that represented 2.39 mm to the .238"number that the overall lash cap length measured. So there is the shim thickness and there is the overall length of the entire lash cap. The etched number only represents the shim portion of the lash cap. I hope this helps. |
Quote:
a 239 shim will have a thickness of 2.39mm |
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