Spun rod bearing

[Mitsubishi]

what goes into fixing a spun rod bearing on a 99 gsx

[Perkul8r]

I know on mine i had to tear the motor completely down and have the machine shop fix it. Its not a quick fix.

[scheides]

Yup, pull motor and full rebuild; you get to pay for a new crank, oil cooler and mebbe oil pump to boot.

[notsostockgalant]

if your rod end isnt out of round and the crank measures within spec with a micrometer and with plasti gauge then its as easy as replacing the bearing.

That route would involve removing the cylinder head, oil pan, rod and piston that has the spun bearing, if everything were to check out though you could put all new rod and main bearings in with the engine in the car. id replace the oil pump as well and make sure to flush the oil cooler and turbo of debris before reassembly.

If the rod is out of round or the crank is marred up pretty bad then you will have to replace or have the crank turned and the rod resized to factory spec, or replace both the crank and rod.

It all comes down to how much damage was caused, or how much you wanna spend.

[C3L1CA]

Just so I don't have to start a new thread, I'll piggy back on this one.

I pulled the pan on my '98 eclipse to find this. Any chance that I can just replace the rod bearing as I'm cheap. I bought it with "rod knock" but when taking the car apart, 2 of the flex plate bolts fell off when taking off the converter and the rest were either had tight or starting to back out.

I found no chunks, oil just looked sparkly. Also, I could wiggle the big end of the rod a little bit on the crank on 1, 2 and 3 but 4 did not wiggle at all. It doesn't move very much at all, but enough to see the movement with my eyes.

Are the rods supposed to move at all?
Also, should the bearings stick to the crank when pulling off the end of the rod? I had to use a magnet to pull the bearing off because it stuck to the crank when I pulled the end of the rod off.




Cyl 3. Pulled this one as it seemd to have the most "movement"





Cyl 4. This is the one that didn't budge




Am I fuxzord?

[1999Gst]

Bump for celica I wanna know same thing

[mondale]

C3L1CA- I don't think that it would be a wise choice to just throw a new set of rod bearings in that engine by the looks of it. Without machining the crankshaft, the bearings will likely start fail shortly after installation. Take your fingernail and run it across the crankshaft bearing surface, if it catches anything at all or even if you think you can feel a variance, get the crank machined. As far as the rod bearings sticking to the crank, I have had that happen to me on 3 different engines that didn't have spun bearings, yet they decided to stay on the crank so that isn't out of the norm in my experience. If you really don't want to spend the money, just throw a new set in, make sure you get your clearances right, and hope for the best! Worst case is you have to pull it apart again if it fails. Hope this helps!
Wade

[Goat Blower]

You guys are hitting a three month old thread, I don't think he's got that car anymore. He's got a 3G now, better know as an Evo.

[C3L1CA]

^Speaks the truth. I currently have an evo and junked that motor besides selling the head.

Every single rod bearing spun and 2 main bearings spun too. I have no idea what the kid did putting that motor together before I bought it but he screwed things up pretty good. It wasn't worth the risk of me just throwing new bearings in it and hoping it didn't fail 2k miles down the road. That car was going to be my ne daily car and I was too cheap to put all that money into rebuilding a 7 bolt so said fuck it and sold all my cars and got me a slow little evo.

[niterydr]

To salvage this tech thread the answer would be: No you cannot just pop in bearings. If the crank has any grooves in it, especially if you can feel them with a fingernail, it is time to tear it down and at a minimum have the crank polished, most likely cut.

[twack]

ive heard a lot of people that refuse to use a turned crank, once it has any form of damage you just find another one. any thoughts

[niterydr]

Originally Posted by twack

ive heard a lot of people that refuse to use a turned crank, once it has any form of damage you just find another one. any thoughts

It really depends upon the extent of the damage. I've reused them in low hp applications, and put in new ones in higher horsepower applications. The stock crank isn't that bad and a micropolish or putting a small cut on the journals and using the proper bearings will be fine.

[C3L1CA]

Wouldn't one want to figure out why a motor spun bearings in the first place?

I thought it was too risky to just get the crank polished/cut and throw in the proper bearings. Maybe it was just improper install which caused the damage or something else? I'm sure it would have been fine with getting the crank polished but it would have been too much money to fix it for what a 7 bolt was worth to me.

[mondale]

Originally Posted by Goat Blower

You guys are hitting a three month old thread, I don't think he's got that car anymore. He's got a 3G now, better know as an Evo.

Gah fail on my part sorry. That's what i get for not looking at the op's last post date. May this thread rest in piece lol.

[niterydr]

Originally Posted by C3L1CA

Wouldn't one want to figure out why a motor spun bearings in the first place?

I thought it was too risky to just get the crank polished/cut and throw in the proper bearings. Maybe it was just improper install which caused the damage or something else? I'm sure it would have been fine with getting the crank polished but it would have been too much money to fix it for what a 7 bolt was worth to me.

Well the discovery behind the failure is always step one. Was it contamination? Stretched rod bolts? Installation error? something else? From there you would make appropriate decisions as what can and cannot be reused.