here are the 2 different kind of stub shafts

left is the factory mirage shaft / right is the cheap one in some kits

 

not to beat a dead horse....

but I'm about to rebuild the motor and eliminate the balance shafts. Coming from straight six's, this is new to me and I've never owned a DSM. You hammer a freeze plug into the back balance shaft hole that is created by totally removing that shaft? Hammer that freeze plug nto the oil pump housing that has a lip seal? Or at least that's what it looks like in a previously posted picture. I would have thought you hammer it into the block, no?



Seems like it might want to pop right out if the crankcase goes under any pressure, as that lip seal isn't going to provide enough resistance to hold it in place like it would if it was installed directly into the block. What am I missing?

 

The freeeze plug is only for the rear shaft that is removed. Put a little JB weld on there and you are good to go. No hammer. It is aluminum and the lip will break if you do that. The front shaft is not removed, but replaced with either a stubby shaft or a tunred down OEM shaft (better solution btw). There is nothing to plug on this one as the stock gear remains in place and the timing belt goes around it. The shaft still spins.

 

yes, the rear shaft is where my question lies. In the pic, it looks like there is still a lip seal installed around the freeze plug. JB weld isn't going to adhere to the lip seal. So you're saying the freeze plug mates directly to the oil pump housing and the seal there is completely removed? So that it's metal to metal? Then JB weld might work, but I'd hope there was a better solution than that. Still confused, any additional information would be greatly appreciated.

 

After all of this is done what trick do you use to get the oil pump sproket bolt tight? You can't hold it with the shaft any longer so just wondering.

 

I used a wrench made for holding small gears. I am sure Snap On or Matco make something for this as well.

 

All this talk of supporting the oil pump gear which connects to the balance shaft....

Strangely I had the oil pump gear which connects to the oil pump sprocket fail.

 

Ouch

 

Any comments on this type of failure guys?

I'm assuming this 'turned down shaft' method would not help the failure above. Correct?

One possibly important point... after only about 50 miles on this brand new engine, we found a leak which was coming from the oil pump sprocket. My mechanic noticed the oil pump sprocket was not even hand tight. He tightened it and the leak stopped. In retrospect, I realize now that how tight the oil pump sprocket is should not effect whether you have a leak or not. So I should have looked into this better. Unfortunately about a 100 miles later the leak came back and REAL bad. And thus the pictures above.

Any ideas on the above would be appreciated.

 

Where you using the short shaft?

 

LOL, that looks familiar I did the same exact thing while removing the balance shafts for my DSM. Anyway, I went to a local store called King Bolt and bought a replacement. Same countersunk type screw, but with an allen instead of that stupid phillips head. I'm pretty sure you can find the same thing at another store.

 

Yes. But in looking at the mechnics of the pump, it's hard for me to really say that not using the short shaft would have helped that situation as the short shaft oil gear was fine in this failure.

 

The gear does look fine but also from just a glance because it is harder to see in pics and analyze the problem but the excessive wear being on the inside pull of the hole. The longer shaft may of helped with the inside wear as it would of kept the gear from being pulled into that direction maybe as the timing belt was too tight and added to the wear maybe along with improper oiling. This is just a thought from my end. Where you using a kevlar timing belt? I don't think anyone really knows why a longer shaft seems to be more reliable on the EVO but it does seem to be a true characteristic.

 

Was using a stock mitsu belt. I'm not sure what happened. I'd agree improper oiling seems likely.. from the very beginning of running the car in it was leaking. So it makes me think perhaps on first start up it wasn't lubed at all, and it just began to grind from that moment.

 

Review After 1000K miles With removed rear shaft and turned down front shaft

Ok I have officially broken in the engine (hard) and I am now reving to 8K. I must say that I am very happy with the decision to remove the shafts. I can not notice any difference whatsoever in vibration. I have poly engine mounts too. Car seems to rev a little quicker and has great oil pressure. No phantom knock, no problems at all. Great mod. Just don't try to do it in the car like I did. It is a PITA.