DIY: Replacing the Bearings in the Idler & Tensioner Pulleys

@Blain You have the option of pressing in a good quality bearing if you have the tools to do it. Otherwise, get the Febest pulley/bearing unit, #

$36 0187-GRJ200 OEM 16620-31012

0187-GRJ200; it's made in China but should still give a few years of service. Or, in your case, you can swap the pulley from the new unit - just remember the bolt is reverse-threaded.

 

I do have a couple Nachi bearings on their way as backup. Never can have too many with the uncertainty of things now. Do you know if the inner size of the china pulley is the same as the Nachi bearing? If so I can pick that up and replace the china bearing with the Japanese one and have a good spare.

 

@Blain Yes, i have the Febest as a backup and measured the dimensions.

 

@Chuy Thanks man.

 

I ordered 2 6302 rmx bearings from rodavictoriausa off there ebay listing. Then I checked their website and ordered a 5203-2nsl from there it was $18 cheaper than the listing they had on eBay and that's with upgraded 1-3 day shipping.

 

After ordering my 3rd set of pulleys from eBay for 70 bucks shipped from asianauto I decided to build a set as spares. Made a removal and install set of press tools. Opened up the bearing from the top drivers side pulley that was making noise. It didn’t look good at all. Almost no grease and it’s that gold color from overheating. There’s another pic of the bearing after removal. A lot of dirt got inbetween the back of the bearing and the pulley. This has only been on my truck for about 8 months. Though I did go thru a silt bed in Death Valley that was horrible.

My buddies truck coming out of the silt bed.

 

Geesus, that silt will find very nook and cranny. How’s the air and cabin filters look?

 

Right in the trash after I got home.

 

Even without all the dust I would have expected more grease in there.

 

Has anyone successfully torque'd the tensioner pully, not the assembly, down? It keeps moving like some have mentioned in this thread before I can reach 39 ftlb.

 

@illjimae I torqued mine to 30 lbs. You also have option of using threadlocker; I haven’t use any. I check my belt and pulleys before long trips, or about every other oil change and have not noticed any issues.

 

No doubt a great topic, but with so much info, it is becoming difficult to understand exactly what bearings are needed and how many.
If I were replacing all bearings with Koyo brand bearings.
Ideally, I want to keep it simple and remove old bearings and install new bearings of the same size and proper type without spacers or adpaters.

To do the #1 idler requires which PN and how many
The #2 idler requires which PN and how many in each pulley?
The tensioner requires which PN and how many.

Thanks

As a followup, is this correct?
#1 idler requires Koyo PN 6302 RMX and requires a quantity of 2 bearings
#2 idler requires Koyo PN 6302 RMX and requires a quantity of 1 brg per pulley
Tensioner requires Koyo PN 5203 size, but which seal type, 2rs? 1 per pulley

As a guess, regarding the PN 6302 RMX, the RMX designates the smaller bore size ID along with the correct seal type.

 

@PMK I added the ‘Cheatsheet’ section in the first post to answer your type of inquiries. You are correct on all counts. The tensioner bearing will have slightly different suffix designations depending on the manufacturer. You want a bearing with plastic/rubber seals; those provide the max contaminate protection. You don't want a ‘Z’ suffix, which stands for metallic seals.

 

Regarding the tensioner bearing, obviously metallic shields are not desired, but do you know the suffix designation for the Koyo tensioner bearing? No suffix, as shown in the cheat sheet is an open bearing with no shields or seals. Ideally, I would expect the same type seal, the red type as on the idlers to be best. Do you know the suffix code for those type seals? The -2rs is black rubber seals.

 

@PMK The Koyo apoears to be 5203 RS KOYO. I currently get my bearings from rodavictoriausa and that’s what they show. They have an ebay store and also sell through Amazon, and direct.
https://rodavictoriausa.com/?s=5203&post_type=product&dgwt_wcas=1

 

Is there any appreciable difference between NSK and Nachi bearings in terms of quality and expected service life? Seems the Nachi is $15 cheaper than the OEM NSK tensioner replacement, at least according to Rodavictoria USA.

https://rodavictoriausa.com/producto/5203-rs-3203-rs-nsk-sealed-bearing-bd17-31-dum8/
https://rodavictoriausa.com/product...40x17-5mm-double-ball-bearings-5203-2rs-3203/

 

@SR-71A Hard to say as there are little to no publications of head to head tests. You can go by the active members in the American Bearing Manufacturers Association that includes, NSK, Koyo, Nachi, and NTN; I don't think you can go wrong with any of these. I have 50K on my Nachi bearing in the tensioner and is holding up well.
https://www.americanbearings.org/page/memberlisting

 

50k miles and cheaper than the OEM NSK unit, thats good enough for me! Appreciate the input.

 

@SR-71A I am waiting for the last coolant hoses to start on an overhaul of my cooling system components. I will be checking the pulley bearings for any play, and report back if I do. Last of hoses suppose to arrive tomorrow. Otherwise, I plan to replace the idlers and tensioner bearings at the 250K coolant change.

 

Decided to go with the AsianAuto Koyo 3 pulley set to replace the #1 and #2 pulleys. The pulley set was essentially the same price as buying Koyo bearings and swapping bearings alone.

Did order the tensioner bearing. Went with a Koyo replacement bearing.

https://www.ebay.com/itm/323395249428
https://www.ebay.com/itm/165021641777

I realize there are several replies regarding the Koyo stuff being fakes. Pulleys are already here, tensioner bearing will be here next week. Unless there is a definite way to tell the fakes from actual Koyo stuff, it will all get installed, hopefully lasting a while.

Total cost was about $110