DIY: Replacing the Bearings in the Idler & Tensioner Pulleys

OK, so I just replaced the two No. 2 Idler pulleys with the

$36 Gates 36173 DriveAlign Belt Drive Idler/Tensioner Pulley

Gates 36173. The original pulleys had a washer on the front and the back. I looked it up and I guess these washers are actually referred to as Idler Pulley Cover Plates. I installed them back in the original positions over the new Gates pulleys. Was that correct?

There does seem to be quite a bit of real estate left on the front of the new pulleys. I noticed they were deeper than the originals.

 

@Jamers99 That does look like the pulley is pushed out too much. Are you able to see the inside of the pulley? As long as the belt makes full contact with the pulley, you'll be ok; otherwise, remove the inside washer - that'll bring the pulley an extra mm in. Or, leave the washer in the back and move the adapter to the frontside - I believe the aftermarket pulleys come with a 17mm to 15mm adapter to center the pulley, but the mounting spot on the timing cover is not very wide; so, you need the OEM washer or adapter back there to spread the clamping force when you torque the pulley bolt.

 

Well I did compare the old pulley to the new Gates pulley and the inside edge lined up exactly when using the inside washer. Without the inside washer the Gates pulley would then move the depth of the washer closer to the engine. The new Gates pulley just has more depth to it. When the belt is on, there is still ~1 mm of space between the inside edge of the pulley and the belt. This should have been the same amount as before.

 

Has anyone tried the labwork kit on Amazon? I mean, even if they are crappy bearings and only work for 5-6 years still a fraction of the cost at $45 for all three pullys.

$46 labwork Idler Pulley Kit Replacement for Toyota 4Runner Tacoma Tundra Hilux 4.0L V6 1GRFE 2003-15

https://www.amazon.com/labwork-Pull...a-818914468961&psc=1&ref=&adgrpid=85980998868

 

I just replaced both of mine as well.

I removed both sets of dust covers. I could not get a satisfactory fit with them on. Even with the gates spacer on the outside I didn’t like the clearance. The gates pulleys are fully sealed so it shouldn’t make a difference if they are covered or not. All the dust covers did on the original was collect water and dirt.

 

Posted this in a different thread, but has anyone tried this kit?

https://www.ebay.com/itm/254293157244

 

Looks like an amazing deal to me if the parts are genuine, which I doubt.

 

Tagging this for later.

 

hoped on

 

Thank you so much for the write up!
My problem was my top tension pulley. It was also the hardest to get the bearing out of. It was completely corroded with dry dust and grim. It took me about 45 minutes just to bang it out of the pulley with the socket and hammer trick.

I replaced my top pulley and tensioner going from underneath the engine. It really is a cake walk going from down below rather than from the top of the engine. I never went from the top once. I'll do the others a bit later the same way.
For the record, I used these: https://www.ebay.com/itm/163767475212 & they fit perfectly
for the tensioner pulley I used these:

FKG 6203-2RS 17x40x12mm Deep Groove Ball Bearing Double Rubber Seal Bearings Pre-Lubricated 4 Pcs

https://www.amazon.com/gp/product/B07SN338XL/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

My diesel mechanic neighbor said to spray PAM on the bearings to make them last a little longer. That completely screwed them up. I'd just leave them alone until you can replace the bearings.

 

I'm confused by the dimensions of the 6303 bearing. The OP says its 10x42x13. But the NSK catalog says 6303 is 17x47x14.

I'm pretty sure this is it: https://www.qualitybearingsonline.c...MIvrC5vty75wIVBeDICh2ZegYOEAQYAiABEgKpnfD_BwE

 

Did all three factory OEM pulleys (idler #1 and boths #2) have the pulley cover plates front and back? I’m ordering new OEM pulleys and going to order new cover plates but the diagram is only showing cover plates for the #2 pulleys. Thanks.

 

Anyone see a reason why I shouldn't put blue loctite on these just for good measure ?

 

I don't really see that you'd need to.

 

AC Delco part # 36173 is a direct replacement pulley and bearing for the tensioner. Just don’t use the provided reducer sleeve.

 

I have that same pulley and compared the offset to the Febest pulley, a known direct replacement, and the offset is a 5mm difference. Since 36173 is not listed as a replacement, it is best to get the Febest or, better yet imo, press out the old bearing and press in the Nachi bearing.

 

I can understand that. The pulley does seem to be slightly set back (lower left) but it’s working fine. I imagine I’ll replace the whole assembly when I have to do the alternator.

 

Looks like its riding on the outside edge which would put a bit extra load on the bearing. Similar to how wheel adapters change the load on a wheel bearing. But the forces here are not as high.

Edit: upon closer inspection, the bearing in the 36173 bearing is 11mm wide; the bearing in the tensuoner pulley is 17mm wide. Dont expect the bearing to last as long. But, it is a viable option as a backup.

 

I recently replaced my tensioner pulley using a 36173 but I pressed out the 11mm wide bearing it comes with and installing a 17x40x17.5 bearing off Amazon. Fit up well and using the provided aluminum sleeve was a breeze for install. The original tensioner pulley gave out and had nothing between the inner and outer races when I took it off. Surprised it was still on the tensioner arm with how torn up the washer was.

All of this just to say that a standard 40mm OD bearing will press into a 36173. I verified the dimensions of the 36173 pulley matched the original tensioner. The bolt fits nicely into the reducing sleeve.

 

I bought a Continental kit. The tensioner is OEM with the casting number milled off. The idler bearings are Koyo with the tensioner bearing a NSK. The number 1 idler with the wide bearing has a shield so I can't be certain of the bearing manufacture.

The old number one pulley the first pic in the upper left has two Koyo6302RMX bearings.