Serpentine Belt Tensioner Replacement

[Mike NXP]

Thanks for the reply, hope you find the noise culprit.

Since I have absolutely no idea who did my last timing belt, and what was replaced, I ordered pretty much everything, including all pulleys, bracket, tensioner and belt.

Had good luck with the Continental belt in a few Chryslers 3.8's, that engine is really prone to rolling belt noises, and tried every belt possible till I installed the Continental, is seems softer and more pliable, so it might not be as strong, but it's very quiet, and forgiving when pulleys don't line up properly. Never broke one.

Have you tried different belt brands? What happens when you spray liquid on the running belt? Does it get quiet for a few secs or it accentuates the noise?

Also considering ordering an alternator while I'm in there, mine is perfect but also, unknown history, and if it's the OEM, it's 280k miles old..

Good call on replacing all components for t-belt. Just get it done with OEM and be done with it for a while. OEM for this rig is Mitsuboshi belt . On these forums it's most noted that the idlers or fan brackets are making noise.


Diagnosing belt and pulley noise isn't that hard but it took me a while to narrow all my stuff down since multiple parts all needed attention. I'd fix one noise and then hear another. . The belt is really the least likely suspect.

If you have the time and budget this is totally a "while your in there" type of repair. Anything that spins just replace it and be happy for another 100k .

 

[AlpineAccess]

The new smaller pulley on the updated tensioner works great; I've been running mine for about 10k. You do need the full tensioner assembly and new pulley; but in my case I found it was nearly the same price as just getting a new standalone pulley.

I pulled my tensioner pulley and pressed a Chinese bearing stolen out of a Dorman Pulley during the summer of 2020 to get rid of bearing noise. That bearing was still working OK when I did my timing belt job this winter around 20k on it; but was freely spinning and so I would assume was beginning to wear out.

I could not find the properly sized NSK bearing in stock anywhere at the time and so I went to Oreilly's with my caliper, measured bearings and pulleys and bought the Dorman unit for $10 all in.

100% agree with @Mike NXP about making sure you knock out as many items while in there as you can. My 210k motor had non-OEM timing idlers and they were shot, the OEM tensioner had been reused by the tech on the second job, fan pulley bracket bearing was going out, etc. All stuff I would have expected the Toyota specialty shop that did the second belt would have done.

 

[Patron100LC]

Thanks for clarifying that the tensioner I got will work, even if the pulley is smaller. I was a bit worried and considered replacing with a pulley and keep the old tensioning mechanism.

As posted before, for future reference and to add to this specific thread:

If we have the bigger pulley tensioner, and want to replace only the rolling part, the OEM pulley that has a Koyo (probably?) bearing is part # 16603-0W010.

Apparently, the mechanism was updated for the smaller size pulley, so probably we can't use a new tensioner with a big pulley, it might interfere it's movement. Couldn't find a part number for the older tensioner, so maybe it's discontinued.

If newer small pulley, we can replace only the rolling pulley using part# 16603-0W030

Or just replace the whole tensioner for a few more $$ with part# 16620-0W101

Apparently the smaller pulley doesn't affect the belt's tension dramatically, so the original size accessory belt can be used, part# 90916-02585

I'll be doing the job soon, I'll be posting some pics.

Welcomed to correct me if wrong.

 

[DCTLC1]

I just replaced the original tensioner at 225K.

The belt was starting to rub the side of the tensioner body. It wore a groove in it and squealed pretty bad at certain rpm’s. I tried changing the pulley but it didn’t make a difference. I guess the tensioner was weak enough it let the belt creep too far over…

These helpful hints are great. I made a few notes from my experience.


1. Remove front belly pan (engine under cover); 8 bolts @ 12mm, recessed bolt is machine thread, others are self tapping

My LC didn’t have a belly pan. So that part was easy!

2. Remove engine V-bank cover; 2 bolts & 2 nuts @10mm, release 1 hose from keeper at rear corner on driver’s side

I removed the engine cover years ago. So I skipped this part too.

3. Remove intake air connector/box; 2 bolts @10mm, 2 hose clamps @ 10mm, disconnect 4 small hoses, pull big tube off throttle body then lift up intake air connector and pull tube off air filter outlet (air mass meter stays with air filter)

The bolts on my air filter box stayed in place once they were fully loosened. Just plucked it out and set it aside. Make sure to keep the 10mm bolts from the intake body separate from the other 10mm bolts. They’re slightly different with a wider head.

4. Remove serpentine belt; release belt tension with 14mm socket on tensioner pulley bolt with racket set to loosen (tensioner bolt is left hand thread)

Super easy. I usually put the belt back on from under the truck. It’s easier to get everything lined up on all the pulleys. I hang the 14mm socket and wrench on the nut and leave the belt resting on the socket. Then when you pull the pulley back from under the truck, super easy because you can use your body weight, you just slip the belt on the pulley with your other hand.

5. Remove pulley from power steering pump; 17mm nut with box end wrench, hold pulley with homemade holding tool (see below) or strap wrench or Toyota’s special service tool (SST) 09960-10010 Variable Pin Wrench available at http://toyota.spx.com/

I just used a strap to hold it while I broke the nut loose. To tighten it back up I shoved a spare wrench through one of the pulley holes and wedged it against the pump housing. Be careful of any of the fluid lines!

6. Remove alternator securing nut and bolt (don’t disconnect electrical connection); 14 mm nut and 14mm bolt, slide alternator forward off stud and let it hang

This was very easy from below. The alternator just shoves out of the way over on to the control arm. No need to hang it.

7. Remove passenger side timing belt cover; 3 bolts @ 10mm and 1 nut @ 10mm, release 2 hoses from keeper

This one confused me for a minute. All the bolts come out ok but the nut would not come off. If the nut is stuck, it’ll keep turning the bolt until it unscrews from the block. Easy enough. But now you have a bolt stuck through the cover and it’s a PITA to maneuver out. I took the cover over to my vise and clamped down on the bolt. Using a 10mm socket, 10mm wrench, and a vise grip wrench (to hold the bolt) I was able to free the nut. It’s easier to remount the cover if you reinstall the bolt first. Then just tighten the nut.

8. Remove small center timing belt cover; 2 bolts @ 12mm; it is tricky to work the cover out of the tight space below the cooling water pipe and even trickier to work it back in

Not so bad getting it out but it is tricky to reinstall. The trick is to push the right side into the timing belt channel a fair amount. Like more than halfway in. That’s was she said. Then you can move the other end into position and install the bolts.

9. Remove the serpentine belt tensioner; 2 nuts and 1 bolt at 10mm

I did one nut and the bolt from the bottom, under the truck. Easier to get under the thermostat housing that way. The other nut is easy from the top.

10. Assembly is the reverse order except position the center timing belt cover under the cooling water pipe before installing the tensioner

I already had the tensioner mounted up with everything finger tight before I reinstalled the timing belt cover. It might have be easier to follow the advise but I didn’t have too much trouble once I figured out the trick.

I didn’t use any power tools. Just socket wrenches and a breaker bar for a couple bolts and nuts. I also didn’t use a torque wrench. Just tighten until you can feel the threads start to go and then back it off a quarter turn.

jk

 

[Mike NXP]

I just replaced the original tensioner at 225K.

The belt was starting to rub the side of the tensioner body. It wore a groove in it and squealed pretty bad at certain rpm’s. I tried changing the pulley but it didn’t make a difference. I guess the tensioner was weak enough it let the belt creep too far over…

These helpful hints are great. I made a few notes from my experience.


1. Remove front belly pan (engine under cover); 8 bolts @ 12mm, recessed bolt is machine thread, others are self tapping

My LC didn’t have a belly pan. So that part was easy!

2. Remove engine V-bank cover; 2 bolts & 2 nuts @10mm, release 1 hose from keeper at rear corner on driver’s side

I didn’t do this this step.

3. Remove intake air connector/box; 2 bolts @10mm, 2 hose clamps @ 10mm, disconnect 4 small hoses, pull big tube off throttle body then lift up intake air connector and pull tube off air filter outlet (air mass meter stays with air filter)

The bolts on my air filter box stayed in place once they were fully loosened. Just plucked it out and set it aside. Make sure to keep the 10mm bolts from the intake body separate from the other 10mm bolts. They’re slightly different with a wider head.

4. Remove serpentine belt; release belt tension with 14mm socket on tensioner pulley bolt with racket set to loosen (tensioner bolt is left hand thread)

Super easy. I usually put the belt back on from under the truck. It’s easier to get everything lined up on all the pulleys. I hang the 14mm socket and wrench on the nut and leave the belt resting on the socket. Then when you pull the pulley back from under the truck, super easy because you can use your body weight, you just slip the belt on the pulley with your other hand.

5. Remove pulley from power steering pump; 17mm nut with box end wrench, hold pulley with homemade holding tool (see below) or strap wrench or Toyota’s special service tool (SST) 09960-10010 Variable Pin Wrench available at http://toyota.spx.com/

I just used a strap to hold it while I broke the nut loose. To tighten it back up I shoved a spare wrench through one of the pulley holes and wedged it against the pump housing. Be careful of any of the fluid lines!

6. Remove alternator securing nut and bolt (don’t disconnect electrical connection); 14 mm nut and 14mm bolt, slide alternator forward off stud and let it hang

This was very easy from below. The alternator just shoves out of the way over on to the control arm. No need to hang it.

7. Remove passenger side timing belt cover; 3 bolts @ 10mm and 1 nut @ 10mm, release 2 hoses from keeper

This one confused me for a minute. All the bolts come out ok but the nut would not come off. If the nut is stuck, it’ll keep turning the bolt until it unscrews from the block. Easy enough. But now you have a bolt stuck through the cover and it’s a PITA to maneuver out. I took the cover over to my vise and clamped down on the bolt. Using a 10mm socket, 10mm wrench, and a vise grip wrench (to hold the bolt) I was able to free the nut. It’s easier to remount the cover if you reinstall the bolt first. Then just tighten the nut.

8. Remove small center timing belt cover; 2 bolts @ 12mm; it is tricky to work the cover out of the tight space below the cooling water pipe and even trickier to work it back in

Not so bad getting it out but it is tricky to reinstall. The trick is to push the right side into the timing belt channel a fair amount. Like more than halfway in. That’s was she said. Then you can move the other end into position and install the bolts.

9. Remove the serpentine belt tensioner; 2 nuts and 1 bolt at 10mm

I did one nut and the bolt from the bottom, under the truck. Easier to get under the thermostat housing that way. The other nut is easy from the top.

10. Assembly is the reverse order except position the center timing belt cover under the cooling water pipe before installing the tensioner

I already had the tensioner mounted up with everything finger tight before I reinstalled the timing belt cover. It might have be easier to follow the advise but I didn’t have too much trouble once I figured out the trick.

I didn’t use any power tools. Just socket wrenches and a breaker bar for a couple bolts and nuts. I also didn’t use a torque wrench. Just tighten until you can feel the threads start to go and then back it off a quarter turn.

jk

Nice tips....

Save yourself the power steering pulley removal step and just remove pump mount bolts and set it aside with a bungee cord.

 

[sailor95]

I think this job is in near future for me, my tensioner has 0 return ability, 390k and it could be the original

 

[Mike NXP]

I think this job is in near future for me, my tensioner has 0 return ability, 390k and it could be the original

Pretty straight forward job . 14mm deep socket to take pressure off and remove the belt . Plan on replacing the entire assembly and hardware .

 

[Les Summer]

This thread is great. Got my tensioner swapped out in my 2000 LX470. It took me about 2-2.5 hours (mainly because I’m slow!) Really not a difficult job.

As others have said, you really don’t have to remove the ps pulley, at least not on a 2000. If you can insert a socket wrench through the pulley to loosen the mounting bolts, just do that. It’s very quick. Also, you don’t have to fully remove the drivers side timing cover. Just pull it out enough to get the center cover off.

At the end it turned out my alternator pulley was damaged I’m not sure how that happened but the new tensioner was chattering and shaking at start up. Turned out the alternator pulley was the culprit. The one side was pushed in and swishing the belt. I recently swapped it out with a Denso one. Who knows!!!????? I’ll swap out the pulley tomorrow. I bent it into submission to get me to work today.

Thanks for the great write up and comments from all

Thank you for this comment. I have a 2000 LC and I wanted to know how to replace just the serpentine belt tensioner pulley, and this answered it.

 

[100s]

Thanks for clarifying that the tensioner I got will work, even if the pulley is smaller. I was a bit worried and considered replacing with a pulley and keep the old tensioning mechanism.

As posted before, for future reference and to add to this specific thread:

If we have the bigger pulley tensioner, and want to replace only the rolling part, the OEM pulley that has a Koyo (probably?) bearing is part # 16603-0W010.

Apparently, the mechanism was updated for the smaller size pulley, so probably we can't use a new tensioner with a big pulley, it might interfere it's movement. Couldn't find a part number for the older tensioner, so maybe it's discontinued.

If newer small pulley, we can replace only the rolling pulley using part# 16603-0W030

Or just replace the whole tensioner for a few more $$ with part# 16620-0W101

Apparently the smaller pulley doesn't affect the belt's tension dramatically, so the original size accessory belt can be used, part# 90916-02585

I'll be doing the job soon, I'll be posting some pics.

Welcomed to correct me if wrong.

As a heads up, the new pulley on the new style tensioner will NOT fit the OEM tensioner on a 2002. The pulley diameter (smaller on the new style) interferes with a post on the original style tensioner. I've got a TB job coming up soon so I'll swap the unit out during that, but off to find a bearing to hold me over.

 

[Patron100LC]

As a heads up, the new pulley on the new style tensioner will NOT fit the OEM tensioner on a 2002. The pulley diameter (smaller on the new style) interferes with a post on the original style tensioner. I've got a TB job coming up soon so I'll swap the unit out during that, but off to find a bearing to hold me over.

Thanks for that.

Good thing I didn't go that way and just ordered the whole assembly instead, since everything was ordered online and I had only 2 days to perform the job, it would have delayed it cause a bump in my schedule.
The new smaller pulley assembly worked great with an OEM sized Continental belt. (not oem belt, no idea how they have the balls to charge $80 for a serpentine).

 

[millenium100]

Thank you OP, and fellow mudders. OPs install instructions were super valuable yesterday when I FINALLY noticed my tensioner pulley.

To contribute, I'll describe some additional symptoms in case others are searching these forums...

For almost 8 months I've noticed, and couldn't put it together:
- screech squeal in certain RPM ranges (in my case ~2800 rpm). Thought this was transmission related as it happened often during shifts (must change belt tension somehow momentarily)
- slight rubber burn smell (well that was the belt)
- general sluggishness
- alternator symptoms including dim dashboard and headlights (replaced 15 months ago)
- when removing foot from accelerator, LC felt backed up almost like exhaust back pressure or a vacuum leak resulting in lack of timing advance
- though my emergency brake was on
- thought my catalytic converters melted and reduced exhaust flow
- a/c intermittently working poorly (full system replace/refresh 12 months ago)

Turns out the tensioner pulley bearing grenaded and stopped spinning. Apparently the belt didn't care all that much and held on, but now all of the symptoms make more sense. A/c, alt, crank (sluggish/ back pressure) all affected. Thankful water pump kept spinning enough to protect temps (fingers crossed).

Elsie feels back to her old self again...

 

[flintknapper]

Thank you OP, and fellow mudders. OPs install instructions were super valuable yesterday when I FINALLY noticed my tensioner pulley.

To contribute, I'll describe some additional symptoms in case others are searching these forums...

For almost 8 months I've noticed, and couldn't put it together:
- screech squeal in certain RPM ranges (in my case ~2800 rpm). Thought this was transmission related as it happened often during shifts (must change belt tension somehow momentarily)
- slight rubber burn smell (well that was the belt)
- general sluggishness
- alternator symptoms including dim dashboard and headlights (replaced 15 months ago)
- when removing foot from accelerator, LC felt backed up almost like exhaust back pressure or a vacuum leak resulting in lack of timing advance
- though my emergency brake was on
- thought my catalytic converters melted and reduced exhaust flow
- a/c intermittently working poorly (full system replace/refresh 12 months ago)

Turns out the tensioner pulley bearing grenaded and stopped spinning. Apparently the belt didn't care all that much and held on, but now all of the symptoms make more sense. A/c, alt, crank (sluggish/ back pressure) all affected. Thankful water pump kept spinning enough to protect temps (fingers crossed).

Elsie feels back to her old self again...

Doubt the pulley bearing had been seized for 8 months. Pretty sure the belt would not survive that.

'Water Pump' was never an issue because it runs off of the Timing Belt....not the serpentine belt.

Glad you got everything fixed though.

 

[RustInPeace]

This is a great thread on this job. Thanks to all who contributed. All i miss is the torque specs for the various parts - which i've found in the FSM except for the Tension Assembly's 2 bolts and 1 nut. Which section is the FSM deals with the Tension Assembly / does anyone know what the torque should be? Also i see two ways in this thread of getting by the Power Steering pump -> either remove the pulley or unbolt the assembly x3. Without the Toyota Special Service Tool for the pulley - is it possible to just use an impact on the PS pulley bolt to get it off?

SST: Toyota US - https://toyota.service-solutions.com/en-US/Pages/ItemDetail.aspx?SKU=09960-10010

 

[Dirt Ferguson]

I'm posting to confirm that I most likely have a bad tensioner pulley. The chirping/ squeaking started this weekend. I have no idea if this part has ever been replaced on my 03LC w 242K miles.

 

[baltistyle]

“As a heads up, the new pulley on the new style tensioner will NOT fit the OEM tensioner on a 2002. The pulley diameter (smaller on the new style) interferes with a post on the original style tensioner. I've got a TB job coming up soon so I'll swap the unit out during that, but off to find a bearing to hold me over.”

Further up in the thread I posted an aftermarket pulley (littens) that has been installed for the last three years(25-30k miles) on an original style/size tensioner. A bearing is easy as well, just depends on your time and parts availability. The new mechanism is the best though more expensive and time consuming.

 

[parkitparker]

Got my belt/tensioner done this weekend thanks to this thread. On the new tensioner from Toyota, how do I read markers for the tightness? The last one was pretty obvious - but can’t find much on the upgraded tensioner. Below is after I replaced belt/tensioner - is it looking good?