Main bearing shims (1 Viewer)
- Thread starter Timmytorq
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They usually all have shims. But the shims are there to adjust main bearing clearance, so maybe they were left out to tighten up a couple loose bearings.
Yes, the steel shim stock they are punched from is labeled with thickness.
Yes, the steel shim stock they are punched from is labeled with thickness.
- Thread starter
- #3
The shim set I purchased from specter does not add up to that thickness. I installed new bearings and the engine shop said they only needed to polish the crank. How do I determine proper thickness needed at this juncture? The Toyota service manual does not show any info on this.
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Install .2mm shims at all caps, measure bearing clearance and adjust shims as necessary to get correct clearance.
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- #5
Good to know... when I took my motor apart a few months ago, I did not find any shims on any of the bearing caps. I’ll be checking clearances upon reassembly.
Only thing I don’t understand is that it seems like adding a shim would not increase annular clearance between the bearing and the journal but would rather result in a an inconsistent clearance. I guess the only other option if clearances were tight would be to have the crank re-turned.....
@Timmytorq are you building an F or 2F (I’m building a 2F)?
Wondering if the F uses shims but the 2F does not. I have not been able to find any info on shims on a 2F (literature, posts or kits).
Just a thought.
Wondering if the F uses shims but the 2F does not. I have not been able to find any info on shims on a 2F (literature, posts or kits).
Just a thought.
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The shims are phased out in the early 1970s. Shim adjustable bearings are an artifact of the engine's 1937 design.
Living in the Past
SILVER Star
When did Toyota start stamping the blocks will the size bearing each main and rod bearing took? My 89 3FE block is stamped and the FSM has the code to tell you which bearing each main and rod had installed at the factory. They also have max/min measurements so you can check wear. Did any of the 2Fs have this? My newest 2F is from a 79 and never had to tear it down.
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All 2F blocks have cylinder and main bearing bore size class stamped on the bottom.
Dunno if any F engine have this? Seems unlikely, since the mains were variable...
Dunno if any F engine have this? Seems unlikely, since the mains were variable...
Last edited:
Living in the Past
SILVER Star
Guess I've lucky. Have a FJ25, FJ45 and FJ40 all with early 2Fs and have never had to tear into any of them.
Toyota ran production , the same on all blocks so therefore it was Cheaper to shim instead of tourquing with plates on each and every block to line boar . As far as your block goes the shop probably line bored to specs. of your crank after a deck plate was bolted on or a head and tightened down to distorted the cylinder and twist the block so when after the rebuild and head was on , the holes, (cylinder bores), would be perfectly round and your crank crank bearings would all be in line .Also the shop wouldn’t use plastic gage to check the clearance. They would use micrometers on the crank and inside micrometers on the journal bearings. They would tightened each bearing caps with bearings in to get a mesurent with inside micrometers to make shute they are to specs with other mesurent taken with outside micrometers on the crank.
Man I’m long winded. Ha
just ask the shop what those mesurents were and do the math there is also a proper way to tighten or loosen the clearances if you haven’t put it together yet . Because after tightenening no bearing is round you can use + or - bearings on 1/2 of all bearings to change the readings. All on top or all on bottom. The eggs shaped bearings were designed after tightening to promote oil Flo to the bearings. Hence if you mic. From side to side the reading will be larger that stright up and down. Some try to take this out , big mistake ! It will effect oil flow , temperature , and oil life. Happy trails yawl
