I recently noticed a few things on my 2009 Fit Sport that pointed towards a bad auto-tensioner pulley bearing. First, there was sometimes a squeal at startup and a quiet ringing sound could be heard from the passenger side. Next, looking at the serpentine belt, a slight side-to-side wobble was visible on the auto-tensioner pulley. After removing the auto-tensioner assembly, the bearing felt gritty and spun too freely.

Even though the tensioner itself turned out to be OK, I doubt a service department would go through the trouble of testing it. The tensioner assembly is ~$175 OEM, ~$90 at RockAuto. Just the pulley with the bearing is $80 OEM, ~$12 at RockAuto. Just the bearing was $7.

Were I to do this again, I would avoid the trouble of pressing the bearing and buy the pulley with bearing from RockAuto and check/hope that a good bearing was used.

I won't repeat everything that's already in the service manual - refer to the Charging - Drive Belt Inspection section, page 4-29 in my book. My notes here are additional information.

The hex casting on my OEM auto-tensioner is 19mm but I used 3/4". No luck accessing it from the top at all, and on the bottom, I couldn't fit a regular breaker bar and socket. I had to use a combination wrench and put a second one on the end of the first to get more leverage.

The service manual has instructions on testing the tensioner spring. You'll need to use spare bolts, 2-3" long and ~8mm diameter. I suggest using wood to not damage the bolts. Make sure your torque wrench is OK going CCW (loosening) direction.

The bolt retaining the bearing has an internal hex drive. You can use 5/16" or 8mm. If you want to follow the torque spec you'll need to be able to connect it to your torque wrench.

The OEM bearing was an NTN 6203LH. NTN describes this as "Single Sealed (Light Contact Rubber)". It looks like it has a maximum speed of 18k RPM. https://bearingfinder.ntnamericas.co...earings/6203lh

I replaced the bearing with a FAG 6203-2RSR-LO38-C3, which is the 6203-2RS from McMaster for $7. The replacement bearing has a maximum speed of 11k RPM.

What speed will the bearing get to? The crankshaft pulley is about 6" in diameter, and the tensioner pulley is about 3" diameter, and redline is 6800 RPM. So the tensioner bearing will experience 13600 RPM at redline. I never redline so I think 11k should be fine, but 18k would make me feel warm and fuzzy inside.

Because of a lip on the pulley, it's not possible to press the bearing out using the outer race. You will most likely damage the old bearing pressing it out.

Cheers!

 

Thanks for posting this up! My tensioner is starting to sing and dance just a little and I've been meaning to address it.
An aftermarket tensioner would normally sit with me just fine, but the price on this one is high for what it is, and I'm freshly disenchanted with aftermarket parts having sheared off a replacement PCV from Intermotor only yesterday.

I really appreciate all the information you dug up for this job. Thanks to you I found a matching Timken bearing on that is a little closer to OE specs, and I intend to try it out.
How did you manage to ID the bearing type? (assuming you didn't pop it out and measure before getting a replacement)

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This is awesome information. I hope to never need it but with 135k plus, I might. When I do need to know this, you got me covered. Thank you.

 

Someone else on this forum mentioned the size. :-)

 

I was hoping you had some secret reference material, but in a way, we all do! Thanks again!

 

UPDATE: Jerks sent me a 6205 instead of the 6203 😂 way too big. Being in the moment I didnt check *before* removing the old bearing from the pulley.. Now It's reinstalled. Used a 15mm deep well socket with the drive end against the inner ring to pound the old bearing out. Needed something sturdy with a bearing sized hole in it to set the pulley wheel on so that the bearing could come all the way out of the pulley (if just setting on wood the bearing would become flush with the pulley against the wood during removal before dislodging completely). To that end I used the remains of an old wheel bearing from a ford escape. Will take pics to aid in clarification.

Added note, need a hex key socket to torque the pulley wheel. 5/16 or 8mm. For me the 5/16 fit slightly better, but I've asked a lot of my husky allen keys over the years, moreso the metric set.

 

Took some pics. Note: I found it easier to remove the belt from the top with a regular 19mm combo wrench and a flathead to scooch the belt off the alternator pulley. For the tensioner, the front bolt's easier to access from the hood, back bolt from under the car. Tensioner comes out under the car easiest. Clearance for a torque wrench is best from under the car for both bolts, even though visibility is impaired for the front one.

Pulley bolt torque: 33ftlbs.
Tensioner bolts torque: 17-18ftlbs, I forget. Firm without breaking anything would suffice for the tensioner.


Starting to knock out old bearing

Got flush with the pulley as mentioned in above post

Finished knocking it out on this old inner race from a ford wheel bearing.


Started the new bearing by placing the old one on top of it and going around with a standard 2lb claw hammer knocking it a little at a time, checking each time to see it go in evenly. Finished using 1-1/16 socket and a 49oz dead blow rubber mallet. If I kept using the old bearing it might've gotten stuck in the pulley with the new one. Though the image shows the drive side of the socket being up, i flipped it for hammering, placing the drive side against the bearing. Seemed flatter/safer

Here's a side-by side with the new bearing installed, verifying fitment. Numbers are visible. Timken 6203-2RS fits and operates within the desired RPM range, nod to OP for figuring out what that is.