Help with serpentine belt not fitting

[Kaylum]

Hi, 

not sure if this is the right place to ask but I need help, im replacing the alternator on my 2011 Toyota Corolla Hatchback and I noticed when I removed the tension bolt it was bent, I forged ahead and removed the old alternator and replaced it with the new one, I bolted the new one in partially and then pivoted it to the front to slip the belt on and it’s much too short even in that position, my question is

 

is there anything that I could have done to make the distance between pulleys too wide and secondly, if someone changed the size of the crankshaft pulley would it cause this problem.

 

the belt is the correct size according to the internet and it was on there before so it doesn’t make sense that it wouldn’t work now, the alternators are also the exact same so it couldn’t be that either.

 

thanks in advance 

[oldcodger]

Hi,

Not sure about your model,  but if the alternators and their pulleys are the same size then the same belt should fit.

Have you looked in the cars handbook which usually shows the route the belt follows over all the pulleys, you might have placed it incorrectly ?

What makes you think someone has replaced the crackcase pulley for a different size , if such a part existed  ?  that would be very unusual .

Several ytubes on changing the belt, they might help ?
 

[Mooly]

Is there a sprung tensioner pulley pulling the belt back and therefore making it appear to small and if so have you held this tensioner 'back' with an appropriate spanner so the belt fits correctly?

 

[Kaylum]

Just now, Mooly said:

Is there a sprung tensioner pulley pulling the belt back and therefore making it appear to small and if so have you held this tensioner 'back' with an appropriate spanner so the belt fits correctly?

 

The belt tensions off the top of the alternator, there is no tensioner pulley and I have moved the alternator into its lowest position which is pivoting towards the engine as is shown in every YouTube video I have watched and it’s just way too short to even get over the alternator pulley.

 

[Mooly]

1 minute ago, Kaylum said:

The belt tensions off the top of the alternator, there is no tensioner pulley

Fair enough. The difference has got to be in the replacement alternator then, different physical size such that the centre line of the pulley is in a different place. 

You say its 'much to short'. By how much is it short approximately? If its by a massive amount then you have to look at the belt run and whether its correct.

 

[Kaylum]

27 minutes ago, oldcodger said:

Hi,

Not sure about your model,  but if the alternators and their pulleys are the same size then the same belt should fit.

Have you looked in the cars handbook which usually shows the route the belt follows over all the pulleys, you might have placed it incorrectly ?

What makes you think someone has replaced the crackcase pulley for a different size , if such a part existed  ?  that would be very unusual .

Several ytubes on changing the belt, they might help ?
 

Thanks for your reply, yes I’ve checked the belt diagram so many times because I was convinced I had messed up somehow but it’s correct, it just seems to be way too short 

 

sorry I should have mentioned in the original post that I had it taken in for a sound and I thought it might’ve been the crankshaft pulley and told them as such and I was thinking that they might have changed it before checking, also the fact that the tensioner bolt was bent makes me think someone has forced the belt on even though it was too small

yea every video shows the belt slipping on easily when it’s in the right position but mine is so short it doesn’t even reach 

 

 

[Mooly]

Try putting the old alternator back and see if it fits.

[Kaylum]

2 minutes ago, Mooly said:

Fair enough. The difference has got to be in the replacement alternator then, different physical size such that the centre line of the pulley is in a different place. 

You say its 'much to short'. By how much is it short approximately? If its by a massive amount then you have to look at the belt run and whether its correct.

 

Thanks for your reply, the alternator is the same I checked it against the old one and in fact I tried to put the old one back in just to see and it doesn’t fit now either

 

the longest part of the belt loop reaches halfway up the alternator pulley but that’s when it’s in the untensioned position and so even if I managed to squeeze it on it would not be able to pivot forwards into its tensioned position, I have checked the belt run against the diagram multiple times and it is correct, I also bought a new belt and they’re the same size even though it’s meant to be the “correct” one based on every online resource 

[Kaylum]

2 minutes ago, Mooly said:

Try putting the old alternator back and see if it fits.

I did try that and it doesn’t fit now either 

[Kaylum]

My only idea is that somehow the “right” belt for my car according to the internet and all of the parts stores in my area isn’t correct, tomorrow I’m going to go to a wreckers and find the same car, pull the belt and compare it, also get a new tensioner bolt as well, I appreciate everyone’s ideas and help

 

I will update tomorrow 

[Mooly]

4 minutes ago, Kaylum said:

I did try that and it doesn’t fit now either 

That doesn't compute does it... all I can think of is that there is 'something' you have to pull against to get it to fit. They are very very tight when tensioned correctly.

1 minute ago, Kaylum said:

tomorrow I’m going to go to a wreckers and find the same car, pull the belt and compare it

If you do that then just slacken it off first and then see if it all fit back. See if there is some hidden sprung pulley somewhere.

[Kaylum]

1 minute ago, Mooly said:

That doesn't compute does it... all I can think of is that there is 'something' you have to pull against to get it to fit. They are very very tight when tensioned correctly.

If you do that then just slacken it off first and then see if it all fit back. See if there is some hidden sprung pulley somewhere.

Well my thought on why the old one won’t fit anymore is because someone in the past forced the belt on when it is too small,  my tensioner bolt is bent almost 45 degrees 

 

there doesn’t seem to be a hidden tensioner in the YouTube videos I watched they simply pivot the alternator forward (towards the engine) and then it slips on and then they pivot the alternator backwards to add tension and then add the tension assembly to the top of the alternator to keep that tension, I’ve added a YouTube video for reference to what I’m talking about 

from about 0:41

you can see how much slack he has to put over the pulley, mine doesn’t reach anywhere near, and then you can see him put the tensioning assembly over the top and no mention of a hidden tensioner

 

 

[Stivino]

There will be a part number on both of the belts, can you either post a photo of them or write them here?

[Kaylum]

Just now, Stivino said:

There will be a part number on both of the belts, can you either post a photo of them or write them here?

Hi,

sure they’re both gates brand part number 6pk1230 which is the only recommended belt for my car and engine configuration 

[Parts-King]

Belts have a part number on them, part of the number usually indicates the length. Did you change the belt? If not you must have put it back on incorrectly, some of those belts can be quite convoluted the way the go around idler pullies etc. Belt length is usually different if fitted with/without air con too 

[Kaylum]

Just now, Parts-King said:

Belts have a part number on them, part of the number usually indicates the length. Did you change the belt? If not you must have put it back on incorrectly, some of those belts can be quite convoluted the way the go around idler pullies etc. Belt length is usually different if fitted with/without air con too 

I didn’t change the belt but after it just wouldn’t fit I went to a parts store and got another belt thinking maybe the old belt had shrunk somehow, they’re the same part number same length and they both don’t fit, I assure you I have it routed the right way I’m using the diagram attached as a reference 

[Mooly]

6 minutes ago, Kaylum said:

, I’ve added a YouTube video for reference to what I’m talking about 

Hmmm. That is very strange.

I really don't know what to suggest beyond the obvious of saying that if it fitted before and you have tried refitting the original now even that doesn't fit then something must have changed.

An interesting one, I'll keep watching. Good luck.

[Stivino]

7 minutes ago, Kaylum said:

sure they’re both gates brand part number 6pk1230

Then, they are both the same.

As Parts King said; the length is indicated in the part number.

 

[Kaylum]

Just now, Mooly said:

Hmmm. That is very strange.

I really don't know what to suggest beyond the obvious of saying that if it fitted before and you have tried refitting the original now even that doesn't fit then something must have changed.

An interesting one, I'll keep watching. Good luck.

Thanks for your help, yea it just boggles my mind, I thought I’d be done in about 30 mins and now I’m without a car for the time being, I think the other one was on way too tight and that’s why it bent part of the tension assembly and probably damaged the old alternator as well, but why the correct belt doesn’t fit is beyond me

ill post when and if I figure it out, or if I have to pay for it to get it towed and fixed by a mechanic $$$$

[Kaylum]

5 minutes ago, Stivino said:

Then, they are both the same.

As Parts King said; the length is indicated in the part number.

 

Yea I don’t know I thought it might’ve shrunk or something so I got a new one just to be sure, that’s the correct one for my car though so it’s so weird that it doesn’t fit 

[oldcodger]

Well one thing not mentioned, why did you need to replace the Alternator ?  was it because the bearings have failed ?   due to the belt being too tight ?

Though unlikely, onder if someone had previously fitted a new alternator but the wrong size so it does not allow the belt to fit without being too tight , eg the body being a different shape to the original and it catches on the engine block too early so not enough clearance to fit the belt properly etc.

Possibly a similar thing could have happened if the wrong size repacement water pump or compressor has been recently fitted ?

 

[Stivino]

7 minutes ago, Kaylum said:

weird that it doesn’t fit

Providing everything else is equal, it must fit unless you are missing something?

[TonyHSD]

Most likely you are doing something wrong and you just can’t see it. 
If necessary lift up the car, remove the wheel and plastics to get access to your belt and start over from the crankshaft pulley. Work your way up . Remember this long bolt that goes into the alternator only hand tight so you can push alternator maximum towards engine, install the belt over and the brackets, set tension by hand again and do the long bolt and re tension from the bracket to adjust correctly. 

[Kaylum]

17 minutes ago, TonyHSD said:

Most likely you are doing something wrong and you just can’t see it. 
If necessary lift up the car, remove the wheel and plastics to get access to your belt and start over from the crankshaft pulley. Work your way up . Remember this long bolt that goes into the alternator only hand tight so you can push alternator maximum towards engine, install the belt over and the brackets, set tension by hand again and do the long bolt and re tension from the bracket to adjust correctly. 

I’d be inclined to believe you if I hadn’t been out there for 4 hours rechecking everything but I’ll give this a go tomorrow, yea I’m 99 percent sure the belt is routed properly and I just don’t have any belt to wrap around the pulley when in the video the guy has heaps 

[Kaylum]

2 hours ago, Stivino said:

Providing everything else is equal, it must fit unless you are missing something?

Yea that’s why I posted here maybe someone had some insider knowledge about a special thing I’m forgetting to do but so far I’ve done everything I can think of 5 times over