Problem with drive belt. Need Help!

[Jstock85]

I am at complete loss. Can someone tell me what I did wrong!!

This is my before and after pics. This is a complete STOCK rebuild. Most of this was taken apart cleaned and repainted. These are the exact same accessory parts including PS pump, alternator, all pulleys and belt.

My problem is when I put it all back together the belt will not go back on. I do not know what the problem is. (hopefully all the pictures will load properly)

[Jstock85]

Not sure why my they are sideways but here is where im at...

[Jstock85]

...

[Jstock85]

Thats the same belt I took off when I bought the engine.

[mongocanfly]

Are You saying it's to long or to short?...the way your holding it makes me assume you think it's short..(blue arrow)... Did you put a wrench on the tensioner..?.(yellow arrow)

[Jstock85]

Originally Posted by mongocanfly

Are You saying it's to long or to short?...the way your holding it makes me assume you think it's short..(blue arrow)... Did you put a wrench on the tensioner..?.(yellow arrow)

Too short. My left hand is holding the tensioner all the way down and thats as far as I can pull the belt

[truckdude239]

Well at first glance whats up with your idler pully????? That looks to be the wrong pully by looking at the bearling guard

[mongocanfly]

His looks like mine dude...

[Jstock85]

Originally Posted by mongocanfly

His looks like mine dude...

Yeah mine is exactly like that. The first pic was to show my belt routing and the second was to show how far I can get it. Thats a ratchet in my hand in the other pic.

[Jstock85]

Originally Posted by mongocanfly

His looks like mine dude...

You mind sharing some info on your alternator? Brand, PN that sort of thing.

Thanks

[87chevy.com]

Forcing the belt on like you did means it's the wrong belt period. You are guaranteed to prematirealy wear out some bearings. Just take that belt off and go to the parts store and ask for 3 belts, each 1/2 longer... return the ones you don't use... simple.

[Jstock85]

Originally Posted by truckdude239

Well at first glance whats up with your idler pully????? That looks to be the wrong pully by looking at the bearling guard

These are the exact same parts I took off the truck. I can't figure it out. My next move will be to take it all apart and start over!

[mongocanfly]

I'm in the shop trying to replicate what your seeing...
1st pic is tensioner relaxed
2nd pic is tensioner all the way over
3rd pic is with belt on...
I did get the same result your seeing when the belt was not down in the power steering pump pulley good...it was sitting up out of the groove..

[Jstock85]

Originally Posted by mongocanfly

I'm in the shop trying to replicate what your seeing...
1st pic is tensioner relaxed
2nd pic is tensioner all the way over
3rd pic is with belt on...
I did get the same result your seeing when the belt was not down in the power steering pump pulley good...it was sitting up out of the groove..

Yes. My belt orientation, tensioner pulled, as far as I can pull it.

That may be the problem. Ill get the wife in the garage this evening and see of another set of hands will help. I first thought the power steering pump wasn't correct but it looks fine. My only other thought is to take it back a part and try again.

[ls1nova71]

Your "before" picture doesn't have an alternator on it, so are you positive that is the alternator that goes with that belt? Because there are two different belt sizes depending on which alternator you have. The shorter belt works with the smaller alternator and the longer one works with the bigger one. You have the big alternator in your "after" pics. So, unless you don't have the belt all the way in the grooves of the pullies, then you have to have the wrong belt for your alternator.

[mongocanfly]

Here's a pic with the belt partially out of the groove on power steering pump...looks just like what your seeing...

[truckdude239]

Attached what stock idler looks like

[Jstock85]

All parts are the ones that came off the engine when I got it from the junk yard. Belt and alternator. This is my first complete rebuild but I'm not a complete rookie in the garage. I have no idea what the problem is. I hope I'm slipping out the grooves and can't tell, Im gonna get some extra hands tonight and see if that works. If not I guess ill take some stuff off and try again. I put a rebuild kit in the PS pump but everything bolted right back into place.

[Steve Cole]

I am having the exact same problem! I thought I was going crazy! All original parts except the water pump. I will double check that the belt is fully seated in the grooves. Let us know if you figure out what the problem is!

[Jstock85]

Took the alternator off used a rubber mallet to tap it down and got the belt on. use the same mallet to tap the alt bolts in and it raised it back up. I was able to take the belt off again but had the same problems trying to put it back on. Not happy because this is obviously not the way this system is designed but nevertheless the belt is on! Still not sure what the problem is but can move on to finishing my project.

[mongocanfly]

That's very strange that it wouldn't work as designed....

[Jstock85]

Agreed. Hopefully I can get this truck running by the end of the month and can research this a little further.

[ls1nova71]

If I were a betting man, I'd say you have the wrong belt. Like I said earlier, there are two different size alternators and therefore two different size belts. Somewhere along the line in the donor trucks 17 plus year history, someone got the wrong one and forced it on, it can be done. The fact that you took it back off and couldn't get it back on again tells me you probably just didn't notice the tensioner maxed out when you tore the engine down, as it likely came right off. There is no way I know of to put the accessories on wrong so that the belt is only an inch or so short. Just get a new belt for the big alternator and you should be golden.

[Jstock85]

Originally Posted by ls1nova71

If I were a betting man, I'd say you have the wrong belt. Like I said earlier, there are two different size alternators and therefore two different size belts. Somewhere along the line in the donor trucks 17 plus year history, someone got the wrong one and forced it on, it can be done. The fact that you took it back off and couldn't get it back on again tells me you probably just didn't notice the tensioner maxed out when you tore the engine down, as it likely came right off. There is no way I know of to put the accessories on wrong so that the belt is only an inch or so short. Just get a new belt for the big alternator and you should be golden.

Could be but thats the belt that came off the engine and who knows what the previous owner did.... the only new part is those pics is the thermostat housing. You are right I do not remember the tension when I took it off. Its possible anything was put on there before I picked up. How do I identify the different alternators in order to get the other belt?

[mongocanfly]

Heres the belt thats on mine..