spun rod bearing

[FullOfProblemsMKIII]

anyone else here spun a rod bearing? is it a bitch to change and do i have to take the motor out? cuz i remember on my honda i left the motor in n juss took the oil pan off n oil pickup n worked from there...is that the same concept?

[corewitz]

yeah same thing with me, my rod bearing spun because of a blown headgasket. Coolant leaked down and ate away the bearings. I took my motor out to fix it but you can leave it in if you take out the cross support and maby the steering rack.

[FullOfProblemsMKIII]

ohh damn....steering rack n shyt...all that is gonna be a bitch...shit i might as well take the motor out and put a new hg and seals n shyt....but its too cold to fukaround like that....wait, is there any clearence to slide the oil pan out?

[TONY!]

I keep hearing this being said on so many sites, “Sure, you can just fix it by taking the oil pan out and changing the bearings.”

My question is: When you get a spun bearing, I am willing to be that the connecting rod is also damaged and chewed up beyong specs, so won't the rod need to be changed?
Won' the crank need to be cut (if not too chewed and beyond fixable specs) and too?
I mic’d up a crank and a connecting rod that had a case of rod bearing both from the same engine and rod knock case.

The crank was worn .059” and the connecting rod was worn .080”.

Total excessive gap on those two parts if just replacing the bearing is going to be .139” and that is roughly 100 times the oil clearance required!

When people just drop the oil pan and “fix” the rod knock, do they actually measure the wear on the crank?

Do they actually look at the bearing tangs in the big end of the connecting rod to see if they are not worn?

Do people measure the wear on the connecting rod to see if it is still within specs?



You also can not take out the connecting rod big end from the bottom of the car; it can only come up one way: up the cylinder becaust it won’t fit the going down.



Just curious as to what I keep hearing about since it does not add up to me—because I hear it a lot…maybe I am missing something…

[FullOfProblemsMKIII]

well...i wasnt gonna be stupid n juss take the old bearings out n slap the new ones on....of course i would look at them and get them checked....but if theyre fine then i'll just replace the bearings n be fine...if they're bad then imma juiss rip the motor out n replace new rods, crank everything fresh....worth it or no? or should i juss find another motor for 400$???

[TONY!]

I can't see how it is possible to have a good connecting rod after it has had a bearing spin inside of it.
I know that the Toyota bearings (OEM) are made up of different layers of metal, but the outside of the bearings is iron, if I am not mistaken.
Some aftermarket bearings are all aluminum.

Back to the OEM type, if those ever spun, I would bet my money that they did do some damage to the rod, and a good chance that the crank may need to be cut also.

[corewitz]

my spun bearing ruined my rod and skuffed up the crank. the crank is regrindable but chances are youll have to get a new rod. Im also debating wether to rebuild mine or replace it with a jdm motor.

[FullOfProblemsMKIII]

yeah i kinda figured the crank n rod will be fucked so im gonna rip the motor out n juss replace it with a stock jdm motor from the junkyard wit less than 40,000 miles on it....prolly save more money in the long run since my motor has 191,xxx miles already....

[TONY!]

I took some pictures to help people see why I believe what I do.

Here are two rods: One in good shape and one that is not good.

Compare the difference:


More comparo pics:

[TONY!]

I have to make a part 2 post because I exceeded my limit...

& More comparo pics:



I would conclude that if one were to have rod knock, they need to get that whole motor out and fix it that way. I can't see how just changing bearings will fix the problem.

Hope that helps people do things the only way I see being fixed properly.