Crankshaft Bearings

[apardal]

Hi!
I've just realised that I've assembled the wrong crankshaft bearings in my rebuilt 4A-GE. I've ran 300 miles or so, and I thought that I should order the crankshaft bearings from toyota the same way as I ordered the connecting rod ones (from the numbers printed in the block).

But the manual also says that one should check for the numbers printed on the crankshaft and then choose the right crankshaft bearings.

The difference between each bearing (mark 1, mark 2, mark 3, etc) is 0.003 milimeters plus tolerance.

Mine are 11211 (reading the block). The numbers in the crankshaft I don't know but I'm sure they aren't all 0 (zero) so I should have assembled some thicker bearings.

The engine doesn't appear to have any problems so far but I have a vibration around 3000 rpm that I think comes from the clutch release bearing... because I don't think the difference between the crankshaft bearing would cause such vibrations.

What do you think I should do?

Replace the bearings? Leave them be?

Thanks in advance

[S.K.]

When I was working in local TOYOTA-dealers repair shop, we put always a MARK2 -bearings, if didn't know right size. We ordered all parts ready before car came to repair (on same time when customer orded a repairing time). So I think that you can let them be there.

[oldeskewltoy]

F/A (TRD... and I assume others) used clearances as much as 2.8 times stock... (minimum of 2 times...)


The key... is not to go to tight.... it APPEARS since the engine is running that you didn't go too tight...
BUT... under extreme heating/running conditions.... you may get a failure... what will likely happen is the engine will seem to lose throttle response... and you'll swear it isn't as rev happy as it once was...

The other extreme will also show itself when it is hot(oil thinning)... the oil pressure will be extremely low since the crank shaft gets oil first in the lubrication system, and loose tolerance mean lower oil pressure

[apardal]

Dan, from your post I get the idea that if it was you, you would keep the same crank bearings since they are a little on the loose side, but not too much (0.003mm). Is that right ?

Best regards

[oldeskewltoy]

apardal Wrote:Dan, from your post I get the idea that if it was you, you would keep the same crank bearings since they are a little on the loose side, but not too much (0.003mm). Is that right ?

Best regards

If it was me... I'd inspect the crank at the very least.... but thats me... I'm an anal retentive SOB since.....

I "F"ed up my first head swap... "forgot" the headbolt washers.... gasket went and I was cursing the whole night as I had to get it fixed for work the next day.... ever since then I check... re-check... and then triple check...EVERYTHING I do... one of the problems of growing old is CRS (Can't Remember Shit) disease.... I've got it in spades....


in essence... what I was saying is, if oil pressure is good... and you don't notice it being flat... you can likely leave it alone.....

[ZDoman]

In my opinion after 200.000km or more the original marks doesn't matter so much. If you have an opportunity to measure the crankshaft with a 0,001 micrometer than you can be 100% right, otherways you can't say anything for sure.

On the last engine I did (engine of SutteR ) I bought the thickest bearings everywhere and I measured the clearance with plastigauge and it was within tolerances of the 4AGE manual.

[apardal]

Trying to find plastigauge here in portugal this week. If I fail, I'll order some abroad.

Thank you for your tips!

Best regards

[apardal]

I again, I'm about to receive plastigauge, as some of you advised.
But I have 1 question. The manual states that one should look for an oil clearance of 0.015-0.033mm between bearings and crank. It also states that the maximum oil clearance is 0.1mm. If I get an oil clearance between 0.033 and 0.1mm, what should I do?

I was said that although the manual and EPC have 5 different size bearings, Toyota only sell 3. At stock trim, I should be using 22322 to get the recommended oil clearance. But what if even with all #3 bearings the oil clearance isn't as it is supposed to be?

Best regards

[ZDoman]

I think first you should wait for the plastigauge and the results
There are 5 different size for the main bearings. The part numbers are:
11701-11050-01 -> 11701-11050-05
or
11701-16010-01 -> 11701-16010-05

What do you use your car for? Because some engine builders says that if you use your engine on high rpms you can have a bigger clearance. And in the TRD bible I read around 0,050 clearance also...

apardal Wrote:I again, I'm about to receive plastigauge, as some of you advised.
But I have 1 question. The manual states that one should look for an oil clearance of 0.015-0.033mm between bearings and crank. It also states that the maximum oil clearance is 0.1mm. If I get an oil clearance between 0.033 and 0.1mm, what should I do?

I was said that although the manual and EPC have 5 different size bearings, Toyota only sell 3. At stock trim, I should be using 22322 to get the recommended oil clearance. But what if even with all #3 bearings the oil clearance isn't as it is supposed to be?

Best regards

[apardal]

ZDoman, my car is mainly for track day use. I'm aware of the recommendations from the TRD Bible, but those oil clearances are for different types of bearings, I think.

I think I'll aim for a clearance between stock recommendation and TRD's.

Best regards