3 different styles of bearings acrossed 4 primary sized available for the 22RX series engines...and out of the 12 styles you have to have the right set or it ainta gonna work.
~Darin <img src="/forums/images/graemlins/baby.gif" alt="" /> [/quote]
__________________________________________________________
>>>*Uhhh....???....Lost me there, my friend...*Time to take you fishing so I can lecture you again, I see..... (Sorry, I know the manual says this from Toyota...*LOL**...) But I am going to disagree....There is only one reason to shuffle around numbered bearing shells, it means the machine work was sloppy. So if the shaft is standard size, order standard size.
Toyota's suppliers were NOT sloppy with machine work, they wanted the account!
I will wager that if I were to measure 1000 sets of say, King bearings with an electron mic, I would find variations of less than .00001" in wall thickness and elipse. Yes, Modern techniques are that good, the process is all digital. The only real confusion here is with the thrust bearing. Many of these engines have literally hundreds of thousands of miles on them before they are torn down. Yes, the thrust face on the crankshaft WILL show a small amount of wear, so nearly all suppliers deliver a thrust bearing that is a couple thousandths thicker. Yes, designed to be fitted, easy to do with emory cloth and a flat sanding block. Usually a dropin fit, but that should always be checked and corrected as needed.
Toyota shows numbers and codes. I will say this bluntly, that is a bluff and a marketing technique, the machine work on ROD ID & Crankshaft pin OD's were excellent.
Now should anyone think that the Japanese would not go to great lengths to create a protectable market, simply note the engine codes with tiny variations in head gaskets etc. This has one intended function: To make it nearly impossible for the aftermarket to fill by mass production, they know exactly what the expected rate of replacement will be. One look at any Honda/Mitsubishi/Mazda catalog will explain this, it works very well.
Toyota was the one Japanese company that began to NOT do this circa 1985, and standardize, part of the reason for their success. Let's just say that relocating just one head bolt every 50,000 engine production runs, requiring a different head gasket worked for retaining market share, but was rough on the bottom line. Still, no company could manufacture, so all purchased from OEM and put that in their sets.
Is this hitting anyone yet?...It hit me many years ago in some board meetings...
Standard is standard, here is why: The shaft diameter has a plus-minus specification. Anything within that swing is acceptable. The normal variation at maximum is .0009" across the diameter. Note here that size variations given are from normal (maximum) to maximum allowable wear.
Several years ago when I was still building engines, we purchased and installed 10 new 22R crankshafts in a run of shortblocks, ALL measured 3.3622" EXACTLY, with runout of less than .0001" end to end.
Same with the rods crankpin diameter, here the spec is 11 ten thousandths of an inch..yes, enough to show a problem in the event of a stackup of sizing dimensions, but this is very rare.
There are also allowable variations in the block mainline, measured in 10 thousandths of an inch, same with the connecting rods. When we resize the connecting rod big ends, we set them at mid, a normal practice, this means we shoot for exactly smack in the middle of a plus/minus swing of less that one half thousandth of an inch.
*Sounds difficult, it is easy...
K...Sorry, complicated if one doesn't do this all day every day, truth is good equipment and tooling makes it easy.
Plastigage is a nice tool, it lets the installer know they have the correct size bearing for the indicated measurements, no builder that is a professional will rely on that for exact.
Yet, even after measurements, once in awhile one comes out on the loose side, or snug.
*Here is why: In operation, the rod big end is held together by two bolts. Good bolts. Still, over time, loading and unloading causes the rod large end to elongate. If it elongates enough, the new bearing will "feel" tight, because the sides at the parting line can rub. This is a NONO, failure is assured.
More common is the installer that "taps" the cap into place, a bit too firmly and the rod large end can distort, with a resulting rub that "feels" tight...Yep...a NONO!
Note that guys like me use a Plastic tapping tool, this distributes loading, never use a metal tool to tap the cap on.
Back to the math intended to make folks roll their eyes...*LOL**...
IF the rod cap big end is within the plus/minus swing, and IF the crankshaft, and IF something silly like rod caps mixed up or reversed has not happened, then the bearing WILL
fit 100% of the time and give clearence that will operate.
I will say this, and I could be wrong, but I doubt it. No bearing supplier on Earth will make and stock a couple of dozen bearing shells in one ten thousandth on an inch variation, which would require the varation to be on either the ID or the OD (crush) side, when it is so incredibly easy to just machine the shaft and housing for the bearing to the correct specs in the first place! I happen to know this because in curiousity, I obtained several different "coded" bearings shells...(Oh, all right, for a Honda) same principle...
Yep, different numbers, identical in every respect except for some marked .001" undersize they used to correct screwups and save money...
*So: When a no-fit situation happens, it is one of a few possibilities: The rod caps were mixed up. A rod cap was reversed. The rod large end needs resized. The crankshaft is off-size.
It isn't the bearing, unless there is a misbox/mismark,..yep, that does happen, when it does, it is obvious.
I would NEVER advise sanding the back side of a bearing for clearence, the only thing that locks it in place is friction....*EB
