Balance Shaft Installation
 

Hello,
Can anyone provide any details on re-installing the balance shaft and new bearings. Taking everything out and flipping the bearings was pretty easy, but putting them back in logically will require more care.

Can anyone that has complete this provide any guidance, and in particular what tool is needed. I have heard mention of a specific tool, but I am not finding anything online. Just generic bearing tools. I don't want to waste and money on the wrong tool.

Thanks!

Like a delete kit?

You can smack them in with a large socket and extension.

I already have them deleted. I am re-installing them based on growing feedback on the topic. Also my rear main seal is leaking, and I suspect this was a primary contributor to it based on what I have researched.

Getting them out with a socket was easy, but getting new bearings in will be trickier, becuase you can't damage the bearing edge on the way in, like you could do on the way out. If you are not using the bearing anymore you can beat on it, and its edge. who cares. But if you are planning on using the bearing as a bearing then you can't damage the lip edge.

Just trying to make sure I get the correct tool, or sizes, or process to not damage the parts. Taking the motor out is not small task in my home garage with no hoist, no lift, just jacks......

Stock pistons and rods?

Yup, completely stock.

Why?

I have been toying with the idea of a 2.3 bulld, but I don't likely have the money or knowledge to pull that off. So, for now stock. Looking to add some daily drivability back to the car. Just doesn't have any torque for normal off the line push since BS removal and 272 cams. I am kind of all over the place admittedly.

Stock bottom end can use balance shafts since its a factory designed engine if its not going to be spun over 8000ish regularly. Mitsubishi engineers designed everything to work together .

Whenever you go with aftermarket pistons and rods, or a crank that will change the harmonics of the engine and the shafts will need to go. You would also need a good dampner with that route as well. Going to a stroker engine will increase harmonics and good balancing/ dampner are a must.

I noticed absolutely nothing when I removed mine.

I would put the "butt dyno" blame on the cams.

I've found using an old oil seal to cushion the blow works for installing bearings. Then just tap them in.

OK, I was wondering how I would not damage the new bearings when installing them. Getting them out is pretty easy with the shaft, but getting new ones in without creating a lip on them is tough.

Besides avoiding the damage on the edge, what about getting the oil holes lined up perfectly. What is the appropriate method to make sure you hammer them in correctly?

When you push them out it doesn't matter, but going back in you have to start at just the right position.

You don't "need" an after market dampener. Have the machine shop balance the full rotating assembly with the factory harmonic balancer. If the balancer is out of balance with the rotating assembly then if too can be balanced out.

Balance Shaft Bearings
 

Guys OP is asking about reinstalling the 4g63 balance shaft bearings in order to reinstall the balance shafts back to stock form.

OP, I hope you have the engine out, tore down and on an engine stand for this. Reinstalling those balance shaft bearings to OEM spec is really not easy with the engine in the vehicle. You can rent a bearing race and seal drive kit from Autozone. This will have the an adequate diameter bearing drive that is made out of aluminum (soft metal) and designed to not damage the outer lip of the balance shaft bearing when "carefully" driving them in with a mallet. This however does not help with aligning the oil supply feed holes on the bearing.

Mitsubishi does have a special tool for this that essentially is a soft material bearing driver with a spring loaded ball insert that will click into place when the bearing oil supply hole aligns with the one in the block (see pic below).

Mitsubishi special tool part #MD998705: http://repairguide.autozone.com/znet...3f80208461.gif

However this special tool is hard to come by and I was able to realign the oil supply oil with the bearing hole by simply using a sharpie mark along the bearing outer face and where the engine oil supply port is along the entrance of the bearing bore. This will take patience and you want to make sure the bearing is pressed in perpendicular to the bearing bore or else it will get damaged. I suggest buying an extra bearing set in case you have to redo the bearing installation.

Good Luck

Put your bearings in the freezer overnight...it will shrink them minutely and make them easier to install. If you have to tap them, use an aluminum or bronze tool to make contact, as they are softer and less likely to distort the bearing. I agree, if you can’t get the proper tool, purchase yourself an extra set of bearings as peace of Mind.

As for the vibration damper, when changing the rotating assembly, an aftermarket damper is a MUST. The stock damper is made with a rubber center section, witch creates a specific harmonic, to cancel out the stock assembly harmonics. It cannot change its harmonics when new different weighted parts are installed. The end result is accelerated bearing wear as the harmonics “hammer” the bearings. Also, a somewhat heavy flywheel can help dissipate the harmonic frequencies by acting as a momentum capacitor. Be sure to use strengthened damper pulley bolts on aftermarket dampers, as at higher rpm’s the stock bolts can shear as the aftermarket dampers tend to have thicker center sections which gives them less thread contact in the crankshaft/crank gear.

Thanks for the input.

I did purchase this

https://www.summitracing.com/parts/w...SABEgKglvD_BwE

The sleeves that it comes with work well. One of the bearings is a tight fit between two of the sleeves, but a little essembly grease made that work.

So, I did purchase a set of ACL bearings, and installed them, and then the BS would only go in half way into the bearing. Assuming I damaged the bearing I bought a set of OEM bearings. tapped the front on in with much softer taps and many more of them. That was better.

I have not replaced the inner bearing. Yet. The BS went in and with essembly lube turns with my fingers grabbing the end of the shaft, but it does seem tight. Not obstructed, but just tighter than I would have expected. Should it spin freely in there now, or should it be snug requiring decent finger power to turn without a tool?

So, currently I have one ACL bearing in the rear and one OEM for the front of that shaft. So, this is the belt driven shaft in case folks don't remember. Oh and yes, the motor is stripped down and sitting on my bench. The only thing not removed is the crank.

Thanks for any comments and inputs!

"Balance shafts are most commonly utilized in inline four-cylinder engines, which due to their design asymmetry, have an inherent second order vibration (vibrating at twice the engine RPM) that cannot be eliminated no matter how well the internal components are balanced. This vibration is generated because the movement of the connecting rods in an even-firing four-cylinder inline engine is not symmetrical throughout the crankshaft rotation; thus during a given period of crankshaft rotation, the descending and ascending pistons are not always completely opposed in their acceleration, giving rise to a net vertical inertial force twice in each revolution whose intensity increases quadratically with RPM, no matter how closely the components are matched for weight." - Wikipedia

Any comments on how freely or easily the BS should spin once in place? Both are in and turn smoothly, but I am wondering if they should turn more easily. I don't have a reference for how this should be.

Are the shafts installed dry? With oil, they should turn with relatively light resistance. They are roughly the same diameter as conrod big ends, so oil clearance should be comparable.
I don’t suppose you measured oil clearance after installation?