DIY: Replacing the Bearings in the Idler & Tensioner Pulleys

Thanks for the reply Chuy. The seller show 116 kits were sold. 99.5% positive feedback. Guess I'll be the guinea pig. I will post the results.

 

Most beneficial bearing study from a cost saving and quality perspective, thanks. I too am concerned about the knockoff koyo's, interestingly, it is the same seller selling the the "new" toprol as the koyo's on Amazon. I wonder if they changed closure and name in response to questions arising from this thread? haha.

Trying to jump back and fourth to track stuff you are recommending down right now, need nice consolidated list next time...because I am dumb. What is the ideal OD size of washers you are putting on the back of these things? The SKF 6302-2RS X2 for #1 idler I found on amazon are reportedly made in India, if that matters to anyone, going to give them a shot. I also have concerns about the NSL on #2 pullys because in the nachi catalog they describe nsl as: Exellent at low speed · The grease may leak from the bearing at high speeds and high temperature. · The grease may leak in case of outer ring rotation.

But i dont know anything about bearings and didn't see a heat or rpm spec, assume they will be ok, figure 150 degrees and 10k rpm. However, wild 10k rpm estimate would be at OD of pully, bearing may be higher, a more ambitious person could figure it out. Attached gene.pdf...Page 4 table 2. But maybe still BETTER than the other options, maybe you can shed some light on this. Anywho, thanks again, alot of fun learning about bearings!

 

Added bearing info for the TRD supercharger. Info collected from post #50.
https://www.tacomaworld.com/threads...s-gates-reference.516475/page-3#post-19456605
@monte1985

 

@lachozaloverboulder
Good observation on the same vendor.
The washers I used are 10mm ID; 22mm OD; and 1mm thick. Stainless steel.
The SKF bearing I received form 123bearing was made in Italy. SKF has manufacturing plants around the world. Presumably, QC should be the same at all the plants.
The "low speed rating" in the Nachi catalog is in reference to the grease sealing qualities of the rubber seal for NSL and NSE bearings. The bearing I used is 2NSE. There is no graph in the catalog for 2NSE but in the previous page you will notice the 2NSE bearing has an extra seal compared to the NSE bearings. From personal experience, I haven't heard any noises on any of the bearings I installed, but I only have about 15K on them. I emailed Nachi if they can define, by RPM's, what is low and high speed and if the 2NSE bearing would be high speed rated. They do list a temp rating of -25 to 100 C, or -13 to 212 F.

Edit note, the 2NSE bearing appears rated up to 13K RPM on the Nachi North America website.
http://nachitech.stage.thomasnet-na...-ball-bearings---two-contact-seals/6302-2nse9

 

The tensioner bearing mentioned in the original post, and elsewhere on this site, is the Nachi 5203-2NS. However, what I'm finding on Amazon and other places is the Nachi 5203-2NSL. Is this an updated part number, or a different application? I've googled myself out trying to find the answer, so I thought I'd ask.

 

@Fullboogie
One Nachi catalog has the 2NSL; another has 2NS. These suffix' refer to the bearing's seals; 2NS normally means the bearing has 2 rubber seals, which is what you want in an automobile application as it provides the best protection against dust and water, and keeps grease from coming out. In one Nachi catalog that has pictures of a 2NSL, it appears the seals don't make contact with the inner ring. However, the pic of the 2NSL in Amazon shows the rubber seal is stamped NS - go figure. Maybe shoot Nachi an email for clarification.

 

I bought this one and pressed it in to the pulley as a backup. Went well. Currently running the Febest and so far so good. Saw your review on the

$36 Pulley Idler Febest 0187-GRJ200 OEM 16620-31012

Febest pulley on Amazon and said, hey I know that guy!

 

Thanks for the input. And I didn't even notice the marking on the Amazon unit. I'll reach out and see if I can get any clarification.

EDIT - OK, Nachi's site doesn't even show an "NSL" suffix for the 5203 or any other bearing of this type. See link below and click on the catalog. Weird.

http://www.nachiamerica.com/p-113/B...row-Angular-Contact-Ball-Bearings#tab_208-tab

 

can anyone shine a light on the 2.7l 4 cylinder replacement of just the tensioner pulley it seems to be a concensus that all the tensioner pulleys are a LH thread, but ive come across this thread https://www.tacomaworld.com/threads/tensioner-pulley.283605/ where the OP used a GATES pulley and confirms that he had a generic RH thread lefty loosey bolt when he removed it, any 4 banger guys can confirm that the 2.7l tensioner bolt isn't a RH thread?

 

This link is gold! Thanks OP for sharing.

 

Received my ebay kit a few weeks ago. Just need to fine time to read the how to and replace.

 

One suggestion:
While you have it at hand print the diagram with the belt routing now and tape it to the inside of the hood with package tape..

It so helps when changing the belt.

 

@Chuy
Tensioner Bearing
Nachi 5203-2NS or 5203-2NSL? Whats the diff?

If you are searching for one of these two Nachi bearings search for the Nachi 5203-2NS bearing. Here is the back story.

Those who are looking for one of these Nachi bearings for the tensioner may discover that as of today Ebay has only a single listing for the Nachi 5203-2NSL and none for the Nachi 5203-2NS. And Amazon lists the Nachi 5203-2NS for an outrageous $236 and the 5203-2NSL for around $40.

It gets more confusing as all these bearings are listed by the same vendor VXB. So I ordered a Nachi 5203-2NSL from them and what showed up was a Nachi 5203-2NS. I then attempted to communicate with the vendor about the reason for the substitution. I received some email from them quizzing me as to why I wanted a particular suffix and whether there was a size issue, etc. Really.

So I fired off an email to Nachi America and here is what I received:

"In response to your inquiry, the “NSL” is an older seal design that we no longer use. We now use the “NS” seal design exclusively in double row ball bearings. Both of these suffixes designate a nitrile rubber seal. “2NS” means a bearing with two seals, one on each side.
Thanks."

Jim Stinnett
National Distribution Manager
Bearings Division
Cell: 312-371-8015
jstinnett@nachiamerica.com
www.NachiAmerica.com

 

@Taco'09

Interesting.
In their current catalog, it shows 2NSL as being the current suffix designation.
In link below, click the first catalog, than Technical Information. It's also listed in the 4th catalog, titled Deep Groove Ball Bearings.
http://www.nachiamerica.com/4-21/Bearings/Catalogs/General/

VXB is a distributor, from their website, https://www.vxb.com/
..."We import, export, wholesale and distribute bearings under our VXB brand name. We are pleased to have our online store up and running 24/7. And now we are official distributors of three top quality Japanese manufactures: Nachi, NB, and FYH..."

 

@Chuy
... all I can say is I appeared to get the info today from the horses mouth as quoted from Nachi above but now ....
FWIW, if someone has a Nachi 5203-2NSL and would like to post some pics for comparison, I have a 5203-2NS is hand I could also post pics.

 

I used the 5203-2NSL for my tensioner pulley bearing. Fit and functions perfect. Paid $39.95 on Amazon.

 

I just replaced my serpentine belt today on my 2012 Tacoma 4.0L with 135k miles. I checked all the pulleys. None made noise and all spun like tops except for Idler No. 1 between the crankshaft and the A/C compressor. That one only spun like 1-2 rotations and then stopped. No wobble or sound however. Does this mean it needs to be replaced?

 

Thanks OP for this information, will be doing mine soon.

 

#1 may be the best one! Sealed bearings should not spin that easily, if they do, they are starting to build excessive clearance. They may still take you some miles. Did you hold each one firmly and shake side to side? Similar to checking wheel bearing looseness. If no play, you're good for now. As for #1 bearing, it's hard to judge from out here. It is somewhat a subjective judgment to spin and feel for resistance. Some bearings come packed that way if the sealed covers are pressed in too tight. It is twice the width of the other idler bearings; so, naturally, it will have more resistance than the other idler bearings. Even though it potentially sees the most abuse sitting the lowest of the idler bearings, it sounds like it's ok if it doesn't have play or feel gritty when you spin it.

 

All the new pulleys I put on mine spun much less freely than the old pulleys I took off. When the bearings are shot the pulleys can spin forever.