Belt Tensioner for the Yaris

[fmicle]

After loosening the alternator a few times, to replace the pulleys, I had a feeling that I hadn't tighten the belt as much as I should have. Sometimes, when I start the engine, I hear a very short (a fraction of a second) squeak coming from the belt, so I knew I had to tighten the belt more. So far I haven't figured out a better way than sticking a wooden mallot between the engine block and the alternator and use it as a lever to push the alternator away from the engine as much as I can - without damaging anything, and then tighten the bolts.

One day, I was checking my wife's Scion xD engine bay and noticed the wonderful belt tensioner that the xD has, which gives perfect control over the belt tension:

http://cqr1dw.blu.livefilestore.com/y1pzoB2Y-Z9l7BygPoC416AzL3HTnGz0Fa90-xL7yIdy2QNisG0vVGIJiqfX9_mpkMv-zgzqrXfytq-P_pvLzV4xWyf7fEhHaYD/IMG_1423.JPG

With help from CTScott and some research on my own I got the part numbers down and ordered them. Around $25 altogether. They arrived today, so after I got home I got to work... It ended up being a little more work than I had anticipated, but all in all, it took me a little under 2 hours, including a trip to OSH to get a hack saw.

Please remember to disconnect the negative battery terminal, since you'll be working very close to the alternator, touching metal pieces, tools, etc. I blew one of my main fuses last time I got close to the alternator...

I ended up getting the entire Scion xD belt tensioner assembly for this project which turned out to be a little more parts than I really needed, as described in the picture below. The Scion xD bolt and washer on the left is exactly the same as the one on the Yaris, so I ended up reusing mine. The other bolt on the right is the attachment bolt of the bracket to the xD engine. The Yaris has a bolt sticking out of the engine already so the bracket slides onto that existing bolt and is fastened with a nut.

So you basically only need these three parts listed below:

http://cqr1dw.blu.livefilestore.com/y1p7WoKQI6A4vdQs_VC3rYHQXwPhmGc5FvINGaVf2wsYtP11Os zSug_BagqbsWkaYJ21pQjcuen-IS2FDGVdlfwlDEFE9DrJrd3/IMG_1470.JPG

This is how the complete assembly looks on the xD:

http://cqr1dw.blu.livefilestore.com/y1pIHdiO6dLQA2MeWnu0hQ5SVWQseILCpy3n0idAiMV-grLf7lPMPzCQ9iHznwJijCrxucqMW2kX4TVfKxyPKMWZrJI4C0 F8dje/IMG_1473.JPG

Unfortunately, the engine attachment point is on one side of the bracket on the xD and on the other side on the Yaris. So that square nut that's welded/glued to the bottom of the bracket needs to go... I thought it was going to be easy, just whack it hard with the hammer and it will fly away. I was wrong... I put a dent in the nut, but it didn't budge. So I went to OSH got myself a hack saw and sawed the tiny welds off until the nut came off.

http://cqr1dw.blu.livefilestore.com/y1pf3mXz-tqVsrnnJ2pw80U51ht_g5165xlZRYk6KZx8a-XItrc22_SsYdmz2fDqNRBaLcqxtMVl0J0U7AgbYXCjYu0gtGFk keV/IMG_1475.JPG

You will also notice that the Yaris bracket is much smaller at the engine attachment point than the xD one. In fact, when I tried to get the xD bracket to slide onto the engine bolt, it just wouldn't fit. Some cutting and polishing was required. Since I already had the hack saw I went to work... I cut that entire lip on the bottom right side of the bracket and then filed around the hole to make it look as close as possible to the Yaris OEM one. The result:

http://cqr1dw.blu.livefilestore.com/y1pV8yfu-RHHPcjPSXGwEmi4f1QX5cdqqTpr-qXDLZlyJEt-3CnuBRKAJ7dvhum9FjqFt47X8WL5FD3CsHAJwPM2fHlnoVBAVF o/IMG_1481.JPG

As you can see below, there isn't much spare in there:

http://cqr1dw.blu.livefilestore.com/y1pgMZcvlN0Yzn37c0kn1cgRcxYihbhROTZ-OIUvvmKKY5frlp5atC_lLjh12mOwBo1q_rotPsqpPXeIzqP0bI HVlaBEvWrneFH/IMG_1486.JPG

And taa-daa, the final result:

http://cqr1dw.blu.livefilestore.com/y1p_5R3X4q21Li2oB4tFpziJ2wdp97Z2kCKZYX5bIkJPT2CW3D HSCkN1mPfklVPEFtRwcYyKz0MHpKK4XoGA6kxcYwJyXwC0Ol3/IMG_1483.JPG

Started her up to make sure I can go to work tomorrow and everything worked fine. I'm sure there will be no more squeaking when starting any more :thumbup:

[devinlamothe]

OMG that is amazing. I need this! My belt always squeals during the winter months because of the constant freeze/thaw we get. This will work a treat.

[kazama82]

sorry..noob question..how to order the parts?..i'm from malaysia..

[fmicle]

sorry..noob question..how to order the parts?..i'm from malaysia..

No idea man, ask a Toyota dealer, I'm sure they should be able to get these for you.

[kazama82]

bro, how you order in the States?..you get it from toyota dealer?.if i ordered from the States, will it be a good idea, or maybe fabricate it?

[fmicle]

bro, how you order in the States?..you get it from toyota dealer?.if i ordered from the States, will it be a good idea, or maybe fabricate it?

www.toyotapartszone.com this is where I got mine ordered from.

[kazama82]

thanks fmicle..plan will purchase during my next trip to the states this summer..:)

[Yaris Hilton]

That's a nice, practical mod. I've had to use a prybar to tension the belt(s) on every car I've owned.

[dean_park]

Great DIY, fmicle!!!
What is the other nut (pem nut welded on) for on the original factory bracket?
is this there to eliminate rotation? The Scion one seems to have that bend that you cut off that eliminates rotation. Did you have any problems with the new bracket trying to move/rotate while tensioning?

Sorry to ask the question instead of looking myself, but right now I'm about 4400 miles from my Yaris :(

[mshekleton]

I tried to tighten my belt because its squeaks all the time. Is the lower bolt (the long one) on the alternator reverse threaded? I can't get mine off to save my life.

[fmicle]

Great DIY, fmicle!!!
What is the other nut (pem nut welded on) for on the original factory bracket?
is this there to eliminate rotation? The Scion one seems to have that bend that you cut off that eliminates rotation. Did you have any problems with the new bracket trying to move/rotate while tensioning?

Sorry to ask the question instead of looking myself, but right now I'm about 4400 miles from my Yaris :(

No idea what that other nut on the original factory bracket is for. It wasn't used on my setup before I did this.

I had no problems tensioning, the tensioner bracket has a little groove that sits on the edge of the big long bracket which doesn't allow it to spin around it's axle.

[fmicle]

I tried to tighten my belt because its squeaks all the time. Is the lower bolt (the long one) on the alternator reverse threaded? I can't get mine off to save my life.

Nope, none of the bolts involved are reverse threaded. Pretty standard metric stuff, don't know exactly what pitch...

[crk06c]

How effective is this? In the image of it employed on the Yaris it looks as if there is a lot more space between the mounting point on the block and the alternator than there is on the xD. Do you feel that this is due to belt wear, or is it that the tensioner is too short? If it's too short, this would have limited use unless something were fabricated. I'd like to know before I try it myself. Thanks!

Also, any thoughts here on using this to apply a spring force for an automatic tensioner? Perhaps remove the welded-on nut, and a nut and washer to the end of the bolt, and place a spring between the end of the bolt and the face the bolt passes through?

[yaris2010RS]

your engine bay pics are really from an 07? wow, very clean, good job

[07dirtyaris]

I know this is an old writeup, just wanted to say thank you. I just did the swap following your directions, which were nicely writted(I used an angle grinder instead of saw). Nice mod doesnt squeek anymore on startup or chirp when i am running low RPMs in 2nd and 3rd!!

[D.Jackson]

Hey, first post here but any how , I am going to try and get ahold of one of those brackets. I have a 2002 Echo and recently the belt broke. I have been having a hell of a time getting the new belt to stop squealing. It really only squeals now at low rpms when the ac compressor kicks in, but really annoying. The whole deal of having to pry the alternator out with a pry bar and then tighten the bolt is just so bush-league in my mind. And the whole time hoping that it's tight enough or not too tight to ruin bearings. I've come up with a couple of designs that I was going to fabricate, but this is excellent. Thanks. Good find!

[valchrist90731]

I use a tire iron to stretch the belt. Use the engine block to then push the alternator.

Don't over tighten like the hulk.
if you use to much strength on any mechanical projects things will break.

Pretty easy.

But hey that's a pretty cheap improvement for 25$.
Good job.

[tmontague]

Nice diy mod and for a good price too. I've never. Had an issue with my belt squealing even in the dead of winter using a pry bar against the block. That being said, if I ever do, I now know how i'll be fixing it!

[NYC-SE]

That's interesting but I don't see one for the Yaris listed.

[brushforhire]

I also have a gatorback belt. I have retightened it several times and it continues to squeal. I will probably do this mod. I do love the belt though. I bought one for my 2000 Tundra and it is awesome.

[YarisLurker]

Did it and it works great! Heard someone say that the alternator causes it because when you turn on the key and dont delay (immediately start it) that the ECU tells the alternator to produce max amps. I had been doing that and it worked but since I bought the parts and installed it I no longer have to delay the start. Thanks for the write up!

[drunix]

This seems like such a nice hack that I am giving this a try, current part numbers that I just ordered are

163810T020 1 $ 9.78 BAR, FAN BELT ADJUSTING
163850T020 1 $ 2.54 Alternator Bracket

While I was ordering parts from Toyota I ordered new upper and lower radiator hoses. My very first car (1968 Fiat 850) taught me to replace hoses BEFORE they break and it's hard for me to accept that modern car parts last as long as they do!! Maybe the Fiat hoses had never been replaced but the ones in the Yaris seem as good now as the day we took the car home. I think replacing them now means I will never have to do it again.

Today I took the serpentine belt out and tried to pull the crankshaft pulley to put the stock one back in (I've had the alloy MicroImage pulley in there for 10 years or so) to try to silence the belt. Could not get the bolt loose on the pulley so I gave up and treated the belt with conditioner spray and put it back in. It's quiet -- for now.

I watched 5 videos on how to remove the crank pulley bolt. But I actually like the MI pulley and I'd rather have the belt tensioner from the 1.8 engine added. (Toyota says it fits 44 cars or something like that... all the XD, Corolla, Matrix models)

The squeaky belt is such a common problem with the Yaris. That and the wheel covers falling off. :-) Ours are zip tied.