3rz timing chain

hey all i just bought a 97 taco with the 3rz looking to do the timing chain cause the vehicle has 339,000 and no known history of timing chain being done im looking into getting the LCE timing chain kit and want to do the blance shaft delete any info into anything related to doing the timing chain would be helpful

 

why do you want to delete the balance shafts? I am curious.

 

As for the timing chain itself, it does take a little bit of work. You will need to lower the oil pan far enough to remove the 2 nuts securing the oil pickup to the timing cover, which is the hardest part. I can help you with whatever you need. I know this engine pretty well.

 

thanks well apparently u can pick up power ront removing them but im not sure how much more work i want to give myself and thanks

 

The main reason for deleting the balance shaft mecanism is because it has been know to be unreliable when the engine is used often at high rpm.

I expect to delete mine when I'm gonna rebuild my engine.

 

im thinking of either doing the timing chain or getting another 3rz to build

 

I am actually about to pull off my timing cover to find a noise behind it, that is why I was curious. Seen a lot of talk about this delete, and people have mixed comments. Haven't found anyone with more than 15k after doing this. My concern is the increased vibration and how it will affect longevity.

 

Can you cite some specific documentation supporting that? They have been using those balance shafts for near 15 years in the Tacoma. If they were "known to be unreliable" I think the engineers would have done something. Also many high performance race engines use them, so I would think they were reliable enough for them.

As for the HP gain, from the research I have done, the word is that the HP gain is only about 2hp, and you lose a tiny amount of torque. This is from another forum where people have actually DONE the deletes and drive them.

 

It's something that I red few times ago but I don't remember where. I guess it starts from the story of a guy who bought a Tacoma with a 3RZ that had failed. The trouble was caused by the balancing shaft system.

In all case, that modifications souldn't be done in a goal of getting more power... The gain will be marginal. Those who claimed 15-20hp are way out. Probably 1-2 hp is expectable...

Normally balance shafts are just a question of confort, they should not impact in internal relability. It has been reported on other forums the vibration is barely noticable after the removal.

For what I've red it's the balance shaft bearing that toast. It's important to remember they are turning twice the speed of the engine. So for race application when red line is often reached, they make the bearing heat and fail. I heard the balance shaft is also one of the reason why the 3RZ has a low red line number... Besides of the bucket shims.

 

Again I would think if they were so unreliable, then Toyota would have removed them a while back. Just a professional opinion of course. I am far from being smarter than the engineers, but I like to keep up with what I can. I also have read a lot about the deletes, and so far nobody has posted any information beyond 15k miles after doing this mod so there has been no evidence yet as to the longevity of doing this. I am still debating deleting mine when I pull my timing cover off.

As far as rotational speed, the #1 balance shaft rotates 1/2 crankshaft speed, and #2 balance shaft rotates at engine speed. Neither shaft rotates at twice engine speed.

 

Hi! I just found this ollld thread, im doing the timing and head gasked on my 3rz and having a hard time finding info on how to make sure the balance shaft weights are at bottom before reinstalling balance counter weight bolt and setting the timing etc. Any tips?