Fixing spun bearings or damaged thrust with engine in the car?

[AL92]

I have a knocking 7 bolt.Not sure whats up yet,crankwalk,balance shaft bearing,something makes a knocking when you rev it up.

So wondering can you fix a walking crank for the bottom without having to pull the entire motor ,can you change out spun rod bearings or main bearings without having to pull the entire engine out?

I thought I saw some guy fix his car for 18 bucks or something but putting in a modified thrust bearing.Again can you do this without pulling the engine just from below.

I will do a rebuild but if can get my car back on the road for now then that would be great.

I realize have to figure out what exactly is making my knocking noise when you rev up my engine.

I also simultaneously have got a bad coolant leak think from water pump and my engine is blowing blue when revved.Not sure these other two problems are related to the knocking.The oil pressure seems fine,engine temp is ok and engine vacuum is good and steady.Need to do some more investigatiing shortly.

But to my original question can you fix things like spun bearings with the engine in the car from the bottom?

 

[gixrman]

I remember reading about a fellow tuner who just replaced his thrust bearing every 20K to prevent CR. He did this by droping the Transfercase and oil pan and then the thrust main cap. Replaced the bearing and RTV'd oilpan. So yea it is possible

 

[gsxtacy]

I am voicing this opinion because my 98' GSX is doing the exact same thing, and I have been here with this situation before.

I removed my oil pan and found appox. 1 TBS. of copper shavings in my oil pan.

I inspected the Balance Shafts, and noticed "Heat Discoloration" around each of the bearings.

I instantly ordered the BS Elimination kit, HOPING that nothing else was damaged.

With the engine in the car, it was a SUPER PITA to get the front BS out so I just left it in and installed the stub shaft on the oil pump. I took my time and put it all back together to find out, it was a Rod Bearing and the Balance Shaft bearings.

Do I recommend changing Rod Bearings/Main Bearings with the engine in the car?

NO. I didn't say it couldn't be done, because IT CAN be done, But I don't condone it.

Few simple reasons.

When the engine turns a bearing, there is a good chance the Crankshaft will need to be turned, especially if the car ran very long after the bearing turned. Emery Cloth will smooth the surface but you cannot accurately remove the "proper" amount of material with it.

Also, Not all of the copper bearing material just falls out of the journal into the pan.
Some of it actually goes through the oil galley's and onto other engine components IE Cylinder head, Main Bearings, Oil Squirters, Oil Filter, TURBO !!!!

Places you really don't want copper to go.

When something such as this happens, it is BEST "IN MY OPINION" to remove the engine while its still in RUNNING condition, tear it down, find the actual problem, remove the piston squirters, Flush the ENTIRE oiling system, replace the damaged components and start all over again.

I highly recommend getting a JDM 7 Bolt engine and KEEPING your original engine for spare parts, Like cylinder head, manifold, intake, turbo, blah, blah.

And before installing the JDM engine remove the Balance Shafts via VFAQ.com, THEN install the engine.

Balance shafts rotate at 2:1 of the crank shaft, hmmm that 7400 rpm shift turns those BS's 14,800 rpm !! Imagine how long the viscosity of 30w oil will last when the oil is already over 200* f .

I'll keep you updated as to how my new JDM engine turns out but, when considering everything, I think its my best bet into getting the most from my new engine.

Here's the link to where I found my JDM 7 Bolt.

www.enginelandinc.com

Hope I helped,

Gsxtacy

 

[Defiant]

I remember reading about a fellow tuner who just replaced his thrust bearing every 20K to prevent CR. He did this by droping the Transfercase and oil pan and then the thrust main cap.

The main caps are all in one girdle.

 

[1fast97gsx]

The main caps are all in one girdle.

Yes they are. On top of that I don't see even with the girdle removed how you expect to drop down the crank with the rear main seal and the oil pump still in place? I don't know how easy it is to change the upper bearings with the crank still in the block, but it doesn't seem like the proper way to do it at all considering the crank will at least need a polish anyways. I would personally pull the motor and do it right if you expect it to last.

 

[gixrman]

The manual (offical Mitsu one that is) say it can be done in the car. And unless there is damage to the crank theres no need to polish it. But I do agree with you on yanking the motor, just giving alternatives.

Forgot about the one piece main cap, thinking of my SBC building days.

 

[Defiant]

The manual (offical Mitsu one that is) say it can be done in the car.

The upper half should be able to be spun out with the crank, so long as you turn away from the indexing tab.

Forgot about the one piece main cap, thinking of my SBC building days.

I still have a sneaking suspicion that tying down the thrust cap with that girdle may be a part of a cause for thrust bearing failure. Notice the 7-bolt doesn't have the thrust bearing cap locked down like that.

 

[gixrman]

Thats a good point. Maybe theres someway you "re-enforce" this by tying it into the block better.