Toyota 1AR-FE 2.7L Balance Shaft - Remove & Replace Saga

[JZiggy]

Balance shaft assembly on the 1AR-FE 2.7L in the Sienna was getting noisy. Lots of rattling at idle, some googling led me to confirm that was the culprit since I'd already taken care of the cam phasor.

Also read some accounts that the balance shaft assembly can be completely removed, oil galley plugged, and there's only a small increase in engine vibes will freeing up a little power. So I thought I'd try it

Oil pan off, accessories unbolted, assembly removed, taken apart

Rather than drill and tap a hole in the block I opted to plug the entrance hole on the balance shaft housing. The housing can be put back on to retain engine block stiffness but remove the actual shafts and stuff. And then the process is reversible.

Housing all ready to go with hole plugged. I drilled three holes at the bottom too to allow oil to drain.

Bolted back up

Oil pickup thingy gets a new OEM gasket

Oil pan is all ready for some Toyota black FIPG

to be continued...

 

[JZiggy]

Results: no bueno

As soon as I cranked it up I knew that I'd need to put a proper balance shaft back in. There was no additional noise at idle but at 2000rpm there was a moderate vibe that through the whole structure of the van. At highway speeds the noise & vibe was only slightly noticeable worse. It was still very drivable but annoying.

All that being said, the van still ran great and had zero problems. We ended up driving almost 2000 miles before I was able to acquire a new OEM shaft assembly and find time to put it in.

So for posterity's sake: you CAN remove the balance shaft and will be OK (no long-term guarantees), but there will be a significant NVH price to pay.

 

[JZiggy]

After getting a replacement shaft assembly from Amayama I realized I had played a trick on myself. All of the video about replacing Toyota balance shafts instruct you to rotate the engine until the balance shafts are at a specific timing, remove and replace, and be on your way. But my balance shaft was already gone...

Kudos to The Car Care Nut on YT who provided the "key" info -- the crankshaft keyway has to be facing straight to the front of the car and then the shafts timed with the dots and lines lined up. Here's a screenshot

Pulled my crank bolt, marked the location of the key, retorqued the bolt, and turned it CCW to the right place

Balance shafts line up like this

And the back ends of the shafts have the flats facing each other

Bolted on, still lined up correctly as per the dots

With the pan back on and full of fresh oil, the van now runs beautifully. The original noise from the worn balance shafts is gone and the new ones are balancing as they should.

Thanks for reading!

 

[Nukeman7]

You can rebuild the balance shaft hardened/shunken rubber dampeners which cause the noise with these KLIFEX replacement parts for $50.

 

[D60]

You can rebuild the balance shaft hardened/shunken rubber dampeners which cause the noise with these KILFEX replacement parts for $50.

I was curious. Tip for others: jump to ~17:15 in the vid

 

[martinq]

That's a great repair story, thanks for sharing with good info and pics.

The feedback after removing is very helpful as I remember hearing stories of balance shaft removal back in the day. The "young punks" thought it was awesome but I was always curious how detrimental it would be to NVH and engine related attachments.

 

[slacktide_bitog]

Nice writeup

 

[Number_35]

Back in early 1998 I was doing a head gasket on my Mazda 2.6 SOHC 12-valve engine and considered removing the chain for the balance shaft.

I chickened out, but always wondered ...

 

[JZiggy]

Good info on rebuilding the rubber parts. I ran across that too late in my quest unfortunately. The original balance shaft started making noise between 150k-200k so I will hopefully not need to worry about it for a long time.

For what it's worth, when I took the old assembly apart to inspect it the little bearings all looked good. It probably could have been rebuilt and kept going for a long time.

 

[D60]

Good info on rebuilding the rubber parts. I ran across that too late in my quest unfortunately. The original balance shaft started making noise between 150k-200k so I will hopefully not need to worry about it for a long time.

For what it's worth, when I took the old assembly apart to inspect it the little bearings all looked good. It probably could have been rebuilt and kept going for a long time.

I feel like there may be some commentary on wet belts here. Hmmm, rubber submerged in oil breaking down in time?!? Say it isn't so!