DIY: Replacing the Bearings in the Idler & Tensioner Pulleys

CHEAT SHEET V6 (use bearing size and type to purchase the correct bearings):
-One Tensioner bearing: size 17X40X17.5; bearing types 5203-2NS, 5203-2NSL, 5203-2RS. Or, Febest pulley/bearing # 0187-GRJ200.
-Four bearings for the #1 & #2 idlers: size 10X42X13; bearing type 6302RMX. You can also use the more common size bearing, 15X42X13 but you need a reducer; see below for details.

For I4 engines:
https://www.tacomaworld.com/threads/2tr-fe-2-7-idler-pulleys.760102/

Cheat sheet updated 3/24/22

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Replacing the bearings in the idler pulleys and tensioner pulley will save you a little $$ and is environment friendly. Unfortunately, Toyota does not sell replacement bearings; you have to buy the pulley with an installed bearing, or for the tensioner, you are forced to purchase the entire assembly. On top of that Toyota uses proprietary sized bearings in the idler pulleys. But, the bearings can be replaced ...

Before replacing the bearings, inspect the OEM pulleys and tensioner for damage as they may indeed require a whole unit replacement. If OK, be sure to clean the backside where dirt/grime may have accumulated. The pulleys appear to be sprayed with a rust inhibitor as they are ferrous and none of mine had any rust. So, be careful using a wire brush. You can always spray paint them.

Pic provided by @Sandman614 on this thread:
https://www.tacomaworld.com/threads/diy-tensioner-arm-pulley.459336/

Best pulley install how-to site I could find (will post a TW site if someone finds it):
http://www.fjcruiserforums.com/foru...154-idler-pulley-bearing-failure-what-do.html

Tensioner Pulley Bearing - This bearing is readily available - the size is 17X40X17.5 (ID X OD X Width). The OEM bearing was an NSK; I replaced it with a Nachi 5203-2NS (this is an obsolete suffix but there are still bearings out there as such; the new suffix is 2NSL). Toyota does not give bolt torque specs; I used 30 ft/lbs, and remember, the bolt is reverse-threaded. @blazze2005 offered 39 ft/lbs as the torque setting based on estimates provided by other TW members.

Some have used the pulley listed for the #1 idler (i.e. Gates 36174) to replace the tensioner pulley. They have found the #1 idler bearing is wider than the tensioner bearing and, hence, the OEM bolt threads in less. There is a risk of stripped threads when torquing the OEM bolt to spec when it has less threads to engage. I found it a challenge locating a longer reverse-threaded bolt. Belmetric.com sells some; I've forgotten length of bolt, and pitch.

Note 4/2/18: Febest offers a pulley/bearing replacement - part # 0187-GRJ200. It is made in China and the bearing has no brand markings - an indication of a low quality bearing, but a viable option as a backup pulley.

Note 2/16/21: @wade9986 reported that Gates/ACDelco 36173 pulley/bearing works as a replacement. It does but the bearing width is 11mm; whereas, the OEM bearing width is 17mm. The 36173 will not last as long but could make a viable backup.

Note 2/7/22: RodaVictoriaUSA bearings carries several 5203 brand bearings, including NSK, Nachi, SKF and Koyo.

I4 engine - Per @kidthatsirish # 16603-75010 (pulley and bearing) replaces the tensioner pulley/bearing on the I4 engine. This part # crosses into 0888-B14 for the Febest part #.

Tensioner pulley on the V6 with OEM bearing pressed out, and pressed in.
... ...


Idler Pulley #2 Bearings - The idler #2 pulleys are next to the power steering and the alternator. The OEM bearings are Koyo and are sized 10X42X13. I could not find anyone that sells these sized bearings. It is best replaced with a 15X42X13 bearing, a common size. You will need an adapter to reduce the 15mm ID to 10mm. I could not find a one-piece adapter so I purchased an insert and installed a 1mm wide stainless 10mm ID washer in the rear, where the inner race makes contact with the engine block. I replaced one pulley bearing with SKF 6302-2RS-C3 and the other with a Nachi 6302-2NSE-C3. The Nachi inner race is a bit wider and you may not need the washer, but I used one anyways. I bought two different bearings just to see which one lasts longer.

Note: If you enter keyword "6303RMX" into eBay or Amazon, you will see the availability of OEM size bearings - 10X42X13. "6303RMX" is stamped on the OEM idler #2 bearings. I have strong doubts about these being quality bearings, including the Koyo bearings labeled as being made in Japan because this bearing is not currently found in Koyo's catalog. In June 2018, I emailed Koyo and asked if they were still making bearings of this size. Their response, "Part number 6302 RMX is the Koyo part number for a bearing closure (seal) only."

Note (12/19/18): I noticed a new bearing on the market listing a direct replacement bearing for the Idler Pully #2. It is from a Chinese bearing company - Toprol, manufactured by Zhengzhou LTD. The part # is 6302RMX - no surprise here. While still a Chinese manufacturer, I like that they don't pretend to be Koyo; the bearing can be found on Ebay and Amazon and is priced under $11.

Note (2/7/22): RodaVictoriaUSA bearings appear to sell authentic Koyo bearings in the right size, as 6302RMX. They sell on Amazon as RDV Bearings.

Idler Pulley #1 Bearing - This pulley is a double wide bearing design and is next to the AC compressor. The pulley is marked "DOUBLE" but the OEM bearing has no manufacturer markings. The bearing size is 10X42X26. I could not find any 26mm wide bearing in inventory anywhere. So, I used two 15X42X13 bearings - SKF 6302-2RS. I inserted a 25mm long reducer through the inner races, and used a 1mm washer, as above.

Note (2/7/22): in conjunction with the note above, use two 6302RMX bearings instead of the 6302-2RS bearings.

I4 engine - This bearing also replaces the bearing in the one idler pulley on the I4 engine.

"Double" pulley with the 2 bearings and reducer pressed in.


TRD Supercharger - The following is trusted but unconfirmed info from another thread pertaining to the bearings used on a TRD supercharger (see Post #43). The supercharger tensioner pulley and two small pulleys near the supercharger have 6303-2RS bearings. The bracket in front of idlers # 1 and #2 on the alternator side has two different sized bearings: the grooved pulley has a 6303-2RS bearing and the smooth pulley has a 6203 bearing. These are the sizes normally associated with these bearing #s:
6203 - 17 x 40 x 12 (ID X OD X Width)
6303 - 17 x 47 x 14

Aftermarket Pulleys - If you already have an aftermarket pulley and didn't keep the OEM pulleys, you can replace the bearings in those. Check the side markings for the correct bearing type; most will be marked 6203, and may be sized 17X40X12. (I looked at a Gates pulley for Idler #1; it is marked 5203X2 and measured 17X40X24, an uncommon size. As I did with the OEM Idler #1 bearing; consider using two bearings, in this case 17X40X12.)

Pressing a bearing - You can press out a bearing at the centerpoint, or inner race. However, when pressing it back in, press it from the outer edge, or the outside race. Pressing it in from the middle may damage the bearings/race. Except for pressing the inserts; for those, you hold the inner race [with a socket] while pressing in the insert. Because of the tensioner & Idler #1 pulley designs, you can use the old bearing to press in the new one. However, use a wide enough washer to cover the outside race. For the idler #2 pulleys, use a washer with 40-41.5mm OD so it catches the outside edge of the outer race but doesn't bind in the pulley.

Bearings - I've listed some of the bearing part #s above. Stick with reputable brands - from Japan: Koyo, Nachi, NSK, NTN; from Germany: FAG; from Sweden: SKF. I would avoid Chinese bearings. VXB is a large bearing vendor on Amazon and they are a distributor for Nachi bearings, but the VXB-branded bearings have low reviews. Whichever brand you choose, get the waterproof version; it will have a plastic/rubber siding to protect the bearings. Most with a metal siding are dust proof, but not waterproof.

OEM bearings in foreground - tensioner; Idler #2's; and Idler #1.


Bushing Adapter/Insert - These reduce the bearing's 15mm ID to 10mm. They are needed to center the pulley when bolting it to the engine. The oil filled bushings are more affordable vs the steel ones - part# BNZ10-15-10 ($2.5) for oil filled; part# IRT1012-1 ($7) for steel. I'm using oil filled but got one steel for comparison. The long one for the double bearing is part# IRT1025-1 ($8 & 25.5mm long); this is steel and I purchased it because an available oil filled was only 20mm long.

Nonmenclature - Some of the bearing physical characteristics are identified by the bearing type. Most will have 4 numbers, e.g. 6302
6 - 1st digit identifies bearing type. 4-double row; 5-thrust ball; 6-single row deep groove; 7-single row angular contact.
3 - 2nd digit identifies robustness. 2-light; 3-medium; 4-heavy.
0 - 3rd & 4th digits identify ID. Multiply these two #s by 5. Except: 00-10mm; 01-12mm; 02-15mm; 03-17mm. Weird, right?
2 - " "
More info here:
http://readtoknowfirst.blogspot.com/2012/01/bearing-nomenclature.html

I bought most of my bearings and reducers from 123Bearing (HQ France). Quality Bearings Online (HQ in UK) is a vendor I discovered subsequently and they appear to have most pieces in stock. Total pricing for bearings, reducers and shipping, but not counting the 10mm washers, was about $85.

 

Excellent write up...I would just like to add that the correct torque on the tensioner pulley is 39 ft. pounds 27 ft. pounds would be for the bolts that hold the tensioner assembly to the block. If you buy a new tensioner assembly from toyota and test what they set the torque at...it's at 39ft. pounds. It took me a while but I finally found a thread where this was tested a couple times.

 

Alrighty, I'll add the 39 ft lbs as a possible setting. Thanks.

 

Great write up

 

Thanks for this write up. I need to replace the bearing in one of the timimg belt pulleys on my '92 and this thread gives me a great starting point.

 

is there a special tool needed for pressing in the new bearings? or is there an easy DIY way to do it? what about pressing them out, is it easy to damage the pulleys if you do it wrong? i've never done it before so it scares me, but the fact that new bearings are a fraction of the cost of new pulleys would make my wife very happy.

 

youtube.com

 

A 12+ ton press works the best. You might be able to use a threaded rod and coupling nut with a combination of washers and cups. A C-clamp used to remove ball joints might also work; you can borrow these free from auto part's stores' loan a tool program.

 

is there any downside to his solution for the double wide bearing? it seems like buying two bearings, a washer, and a reducer is a lot more that could malfunction than just spending a little extra for an entire pulley. thoughts?

 

thanks to the write ups on this and a couple other forums i was able to successfully swap out my pulleys last weekend. i opted to purchase new OEM #1 and #2 pulleys because i didn't feel comfortable having extra moving parts where there should be just one (and i have a dealership hookup), but i did pick up a replacement bearing for the tensioner pulley and my motor sounds much better. thanks again, TW!

 

thanks for the write up

 

This writeup really helped me out. Just wanted to say thanks!

 

Thanks for writing this up. Does the part number for the tension pulley you listed (

$50 16603-75010 Belt Tensioner Pulley

16603-75010) also fit the v6? When I search Toyota parts the fitment only lists the I4 variant. If not do you know of what it is for the pulley only?

 

@Benny123 To my knowledge, no one makes a replacement Tensioner pulley/bearing combo for the V6 4.0 engines. Your choices are a new assembly or bearing replacement (or salvage yard). Some have fitted the pulley from the #1 idler (

$45 Gates 36174 Idler Pulley

Gates 36174) but the bearing is wider and reduces the # of threads engaged by the idler bolt. Because that bolt is reverse threaded, finding a longer one is not easy.

 

It appears Febest part #

$36 0187-GRJ200 OEM 16620-31012

0187-GRJ200 is a direct replacement tensioner pulley. I have not had the opportunity to install it, but the bearing and outside dimensions of the pulley match OEM. The issue will be quality; it is made in China and the bearing has no markings - an indication of a low quality bearing. It was $26 on Amazon. For that price you can get a good quality bearing to replace OEM. But, if your pulley is shot; this will be a good option.
@Benny123

 

Thank you for this. I have been racking my brain trying to find this. I had bought a cheap $30 tensioner assembly from ebay and tried that one, and it squealed louder than the original (inadvised) . I suspect this will help thousands of Taco owners.

FWIW I used a couple Febest pulleys in my 4runner and they were perfect. Time will tell how long this lasts.

 

Replaced them with the febest tensioner pulley. Fits perfect, appears the same and is quiet. OEM top, new bottom. Thanks @Chuy

 

@Benny123
Excellent; thanks for posting. I have very little faith in the Chinese bearing, but should give at least a couple years of service life. I would clean up the OEM pulley and replace the bearing with a good quality one.

 

#2 idlers, 6302RMX Koyo, no bushing needed

 

@1largemouth Nice find. Looks like a new product as it is not listed on their current eCatalog, or could be NOS. Or, a knockoff; I found a Chinese manufacture offering to make this bearing:
https://yidingbearing.en.made-in-ch...p-Groove-Ball-Bearing-Japan-Koyo-6302rmx.html
I will try and contact Koyo, 1-866-TOYOTECH.