Toyota FJ Cruiser Forum banner

Idler Pulley/Bearing Failure, what to do:

296K views 248 replies 116 participants last post by  darksidetourist57 
#1 · (Edited by Moderator)
I know this has been discussed in many threads but it got difficult to sort though all of it so here is what I could gather.

First, THANK YOU to everyone that has been putting in so much work to figuring all of this out over the past 4 years!

OK, here goes...

As most of you know, the factory Toyota bearings inside the idler pulleys on the FJ are not sealed... go figure.

What does this mean?
Well, if you do any type of water crossing or playing in the mud, it could potentially get dirt into these bearings and sooner or later they will start to go bad.

How do you know if you have a bad bearing?
The first clue is a 'screeching' noise coming from under the hood, usually a couple of days after a water/mud crossing. Most likely, the noise will start to get louder and louder with time and RPM. In some cases, the problem has been with other pulley bearings as well, such as the alternator, power steering, etc... however, in over 90% of the cases, the bad bearing(s) will be in the idlers (usually uppers).

How to prevent your bearing(s) from going bad?
Next to staying out of water and mud, there really isn't a sure way of keeping the pulleys from going bad. One thing that has worked for sometime is to 'wash' down the idler pulleys after wheeling. Take a small water bottle and punch a hole into the top so that you can 'squirt' the water at the pulleys, usually works very well. Also, here is a write up on how to properly clean your pulleys:https://www.fjcruiserforums.com/forums/how-technical-articles/39749-pulleys-proper-cleaning.html This requires disassembly of the Serpentine system.

OK, OK, what bearings, in what pulleys are we talking about here really?
There is some confusion, not only on FJ forums but also in the different manufacture year manuals, as to what idler is 1, 2 and 3, so for the sole purpose of this write up, I will stick to the terms, 2 uppers (Pictured as #2 ) and 1 lower (Pictured as #1 ).

In this diagram, taken out of the 2007 FJ Cruiser Manual, the 3 idler pulleys are circled in red along with the belt tensioner circled in orange. All 4 of these pulley bearings are not sealed and could potentially get damaged in a water/mud crossing.


What to do if your bearing(s) are bad?
If you still have warranty on your truck, take it in! Usually the dealer will replace the idler pulleys at no charge under warranty.

If that does not work, or your out of warranty (like me) then I'd suggest at looking for sealed bearings/pulleys.

The factory non-sealed pulleys are Koyo.

ACDelco, Dayco, Gates and Goodyear, all make sealed idler pulleys for the FJ or at least they claim to. After looking at some of the aftermarket pulleys, it appears that most (if not all) use NTN Canada Bearings. If its the same bearing for all companies, I do not know.

One issue I have run into personally, is that the aftermarket bearings require a sleeve (bushing, spacer, or what ever you want to call it) in order to work properly on the FJ however, some (like ACDelco) make an incorrect sleeve and others do not have one at all...

The correct sleeve for the upper, should be around 0.405" ID
(I do not have the measurement for the lower at this time)
In any case, there should be almost no play on the bolt what so ever!

So which pulley(s) do I buy?
Great question and really what this thread is all about! My recommendation is Gates! Why, I have had good luck with Gates products in the past and from reading a lot of threads about this issue on different FJ forums, most agree that Gates is the better choice.


Gates:


Two Upper Pulleys (#2 ): 36173 Product Detail Page
One Lower Pulley (#1 ): 36174 Product Detail Page
Tensioner: 38411 Product Detail Page
Serpentine Belt: K070834 Product Detail Page

[Added by Winterpeg]
NAPA part numbers:

Here are the part numbers for the NAPA pulleys....
drivebelt idler pulley, lower - UNR 36174 - $ 112 CAD
drivebelt idler pulley, uppers - UNR 36173 - $ 93/each CAD
drivebelt tensioner assembly - UNR 38411 - $ 184 CAD

American napa uses NBH as the line code rather than UNR
The actual numbers are the same.

Where to Buy?
You can get the parts where ever you want but the best deal so far that people have found is from RockAuto. Their prices are great and with one of the Coupon Codes from RetailMeNot you can safe an addition 5%.

Tensioner Pulley Warning!
Apparently the upper pulley part number cross references as the pulley on the tensioner and some have ordered just the pulley instead of the entire assembly. After further research (not by me) it turned out that this was not the case and that the pulley did not work. Apparently the spacing and dimensions are incorrect. My suggestion is just to replace the entire tensioner assembly and avoid any potential damage that could occur by installing the wrong pulley.

How to determine which one is bad?
When the engine is running, carefully look at the pulleys and see if any of them is 'wobbling'. If that does not work (and usually its not very accurate), with the engine off, undo the tension on the serpentine belt and spin each tensioner individually. Usually you can tell which one is bad by a rapid stop, a wobble, squeal or anything out of the ordinary.

Disassembly:
If you've never worked on a Serpentine System before, please have someone help you that has. It is not complicated by any means however, any misalignment of the belt could cause serious damage to parts, you and the engine. Also, be careful working with the tensioner and around the radiator fan!

I'm not going into to much detail, anyone working on this should know how to do this.

To loosen tension, just rotate the tensioner counterclockwise (to passenger). There is a little loop at the bottom you can put a allen wrench in to hold the tension while your working.

The pulley bolts are fairly tight but should break loose with a good wrench or breaker bar.

Here is a picture of my two upper pulleys, the black ones are the new Gates (notice the sleeve that comes with them on the left side) and the silver ones are my old factory ones (Koyo):


On the factory setup, the two upper pulley bolt actually has a 'dust cover'/washer on it. I did read that some did not install it again but after a good cleaning and taking some measurements, I decided to put it back in. The center riser is a perfect fit on the sleeve so it will not damage the bearing and the OD is just perfect to sit inside the pulley, here is a picture of the parts:


At this time, I have only replaced the two uppers, mainly because my tensioner and lower idler are still in good condition and unfortunately both are currently on backorder. I will update this thread once I can get my hands on the lower and a tensioner.

EDIT: For Tensioner Pulley Replacement please refer to post 3 in this thread by 5Greens: https://www.fjcruiserforums.com/forums/maintenance-tech/127154-idler-pulley-bearing-failure-what-do.html#post1888318

Installation:
Do what you just did in reverse. Seriously tough, it is very easy to loose the sleeve or washer during the process. My recommendation is to put it together outside the vehicle (insert sleeve into bearing, lay the washer on top, insert bolt). Once in place, tighten by hand until snug (make sure that the bolt is 'inside' the pulley to confirm that the sleeve is set in all the way).

Now torquing to 'factory specs' is an entire debate in itself! Apparently there are variations in the different manufacture year manuals.
My FJ is a 2007 and out of my 2007 manual this is what I got:




Rout belt, double and triple check to make sure that the belt is perfectly routed and seated on all pulleys. BTW, if you did not replace the belt (I'd recommend replacing if you have more than 70K on the truck) please check for damage before installation!


To conclude, part numbers and torque specs (2007 Manual):


Again, I will update with any information I and/or others have.
 
See less See more
7
#3 ·
Thanks for assembling the parts list for a complete Belt system overhaul. Reading this post made me replace all the pulleys along with a long overdue belt replacement. I used your parts list and shopping advise for a total cost just under $200. My upper idlers were bear metal instead of black. The tensioner assembly is the bracket for the alternator and A/C compressor. Replacing the tensioner assembly requires the removal or relocation of the alternator and A/C compressor. I found it easier to remove the fan and shroud along with the battery to gain access. 6 hours after starting the job I drove away. I had not noticed the noise from the belt system before, but after the lack of noise was noticeable. I should have done in sooner with 166K miles it needed to done.


Gates #36173


Gates #38411


Remove Alternator wire cap clips on sides


Remove Alternator wires and wire bracket


Remove Alternator mount bolts and remove Alternator.


Remove bolt on bracket for A/C line to allow compressor to be moved.


Remove bolts ((4) one not shown) allowing compressor to be moved.


Remove tensioner 5 bolts.

Reverse steps to reinstall.
 
#4 ·
Fantastic thread! A+
 
#6 ·
Well I am now replacing my second set of bearings ( well toyota did the first 2 under warr) and I think replacing the whole pulley is a waste of cash. Went down to a local bearing shop and picked up the 6302 bearings for $13. ea. pressed them out of the pulleys and have a local machine shop making me up the bushings for $20. So from now on if I ever need to replace them again, all it will cost me is $13 per pulley.
 
#7 ·
Reviving an old thread, i have to do this but i am finding mixed info for 2009 FJs. Did these change ? some sites give me 3 of the same, Dayco 89158, and some 2 different models 1x 89169 and 2x 89158 , again in Dayco. Most of the info available comes form the 2007 FJs, could they have changed models ?

Anyone can help me on this ?

Thanks
 
#11 ·
Seriously? On a 4WD truck sold to be off road capable and an owners manual showing you how to rock crawl and submerge the truck safely?

Show them the brochures with pics of the FJ off roading and then in a voice clear enough to be heard in the sales room ask them why they are denying warranty when an FJ is taken on a dirt road.

Mine is starting to whine at 20K and I'll be damned if they will deny warranty for "mud" or anything else that is normal usage. The truck isn't abused.

I could see a denial if they found damage under the truck like a smashed skid plate or such, but just mud under the hood? Sounds fishy.
 
#14 ·
great post and illustrations!
 
This post has been deleted
#16 ·
So how do i know if I need just the bearings vs the whole mount?!?!
I need to do this. I went wheeling through mud/water and after I powerwashed the motor it's REALLY bad now.
It pretty much looks as though the bearing(s) are the only component that would be subject to failure.

This is a great thread/write-up! Thanks and kudos to the OP and to all who contributed additional info. For those of us that like to do our own mods & upgrades, retro fitting sealed bearings to the idler pulleys is a relatively easy and inexpensive addition that would make a very good and welcome improvement for off-road performance, longevity and peace of mind.
 
#19 ·
Got to give the OP credit for a outstanding write up! I replaced all the idler bearings on my 07' with less than 20K the first time by the dealership and they failed 8K later. I haven't gone back to the old threads but if I remember there was no need to replace the Idler tensioner assembly. You could use the old sleeve and washer on that particular bearing if I remember correctly. There was a list of all the bearings numbers and you could buy them all from Nappa Auto parts for $60. It only took me 20minutes to remove and replace them all.
 
#21 ·
Hi all
Just to get it clear to me ,i have just ordered the 3 bearings from rock auto

Two Upper Pulleys (#2): 36173 Product Detail Page
One Lower Pulley (#1): 36174 Product Detail Page
Tensioner: 38411
WHAT I WANT TO KNOW IS are they the right size on the inside or do i need to put a sleeve,if i do what the best way to do it .

Yes got sea water and sand in them !! mybe they better put NOT WATER PROOF on the car some where see how meny the sell then (i love my fj but man thats dum) :thinkerg:
 
This post has been deleted
#22 ·
I have an '08 and the new pulleys were the right size (no adjustments needed). It was a very straight-forward process following his directions. The only real pain (for me) was getting to the bolts on the AC compressor.

Hi
thanks for that is good to know ,my bearings went bad a long way from home so i found one bearing and the other two i cleaned up and put grease inside by pulling back the cover and pushing the grease with a pin ,put them back and got 1500km back to home .mybe good to know too .
 
#23 · (Edited)
Are the compressor and alternator removed to allow access to the bottom pulley? Great thread! I am going to be replacing mine soon, i was not sure if it is possible to get to the bottom without removing the compressor/alternator. I was curious as to why the alternator/compressor needed to be removed. Mine is making a very faint sound so, I will try to determine which pulley it is, I suspect it may be one of the top pulleys, those look to be easy enough to change.
 
This post has been deleted
#24 ·
Yeah. The compressor is literally bolted against the idler assembly. You HAVE to remove the compressor BOLTS and then you can leave the compressor dangling (off to the side) to replace the idler assembly. The compressor bolts are a MAJOR PITA!
Got it thanks! I'm going to start with the three pulleys and go from there. What is odd is that mine do not make noise often, once in a while. After reading this thread, I figure I may as well replace the pulleys to be on the safe side.

Thanks again for the response!
 
#26 ·
Yes, you only needed the pulley, not the mounting bracket.

DEWFPO
 
#28 ·
Do you drive thru very deep water or mud?

If you don't have any of the typical squealing noises, then I would just replace the belt. When you have the belt off, check each of the pulleys including the water pump and alternator for smooth movement, no wobble or any unusual noises. If all is well, install the new belt and be on your way. If one of the pulleys is going bad, replace all 4. I wouldn't touch the water pump or alternator unless you are having obvious problems. They are not typical maintenance items.

DEWFPO
 
  • Like
Reactions: Sanderhawk
#30 ·
Hi there

well if your thinking of going in deep water then good to put water proof ones in !!! the one you have in now are not thats sure !!:wave:
 
Top