Anyone break an idler pulley off?

[ZmanM3]

So I finally got the belt size I need to run my 2.95" S/C pulley. It is exactly 110.25" long Goodyear gator back. So I took my car to my buddies house and we but the new belt on and the smaller S/C pulley. We got everything on and buttoned up. I crank the car the engine goes and then I here a very loud snap and hear metal falling. I immediately shut down the car. Under the car we see oil dripping down and find the lower idler pulley that goes behind the alternator on the Saleen S/C setup. The oil filter was busted up from where the idler pulley collided with it. The idler pulley and bolt snapped out of the timing cover.

Has anyone else broke off an idler pulley like this? How had is it going to be to swap out the idler pulley. I know I'm going to have to take off all the accessory pulleys and the crank pulley. Other then that is should be pretty much a straight swap correct?

I didn't have a camera with me tonight. We plan on hopefully tearing down the front end of the car tomorrow and get a good look at everything. I am hoping that nothing else is damaged. My friend thinks that the mount for the oil filter may have been damaged too. Is that part of the engine block on a teksid block or does it bolt in?

 

[psfracer]

That sucks. Silverpoison broke one off of the timing cover also, perhaps you could PM him, see if you can find out what he did.

 

[cekim]

Is that part of the engine block on a teksid block or does it bolt in?

In both cases, the pulley bolts into the front timing cover.

I believe in both cases (definitely for the 05+ block) the oil filter screws into a assembly that bolts to the block and can itself be easily replaced (it includes both the seat of the oil filter as well as the water return).

Depends on how you broke it - if you tore out the boss on the timing cover, you either need to replace the timing cover or have it repaired - but they are relatively cheap - it's likely "easier" to replace the entire timing cover...

You do have to pull everything off the front including the harmonic balancer though...

 

[ZmanM3]

Thanks Mike. We were thinking all the accessory pulleys and crank pulley were going to have to come out. Is 99 cheap for a timing cover? I'm also kind of interested in how I broke it. I don't think I misrouted the belt at all but I can't think of what else could have caused this other then that or a defective timing cover. But there has been quite a bit of abuse that it has survived already. The boss is were the bolt screws into correct? If so the whole thing pretty much broke off and is still on the bolt for the idler pulley.

 

[cyazo6]

I had that pulley disintegrate on my car and it left me stranded on the side of the high way. It's the only time I've had a brake down. I believe the pulley's bearing started to go. The pulley wore half way through the Saleen bracket before it completely let go! I was lucky and the only thing that got damaged was the belt.

 

[akula52]

freakin sucks

Zman, That blows! It seem like when you get everything working, another issue pops up. I hope you get it worked. r/Rich

 

[ZmanM3]

I had that pulley disintegrate on my car and it left me stranded on the side of the high way. It's the only time I've had a brake down. I believe the pulley's bearing started to go. The pulley wore half way through the Saleen bracket before it completely let go! I was lucky and the only thing that got damaged was the belt.

I've shredded a few belts. I keep spares in the trunk along with all the tools to swap them out. Actually my pulley seems to be a-ok. Its still attached to the boss and spins freely. The problem is that the boss is no longer attached to the car.

Zman, That blows! It seem like when you get everything working, another issue pops up. I hope you get it worked. r/Rich

Thanks Rich, I'm hardly the only one with problems though. Your still fixing that fuel problem and good luck with that. Any word on when your going to get that new return style fuel hat?

 

[cekim]

Thanks Mike. We were thinking all the accessory pulleys and crank pulley were going to have to come out. Is 99 cheap for a timing cover?

I said "relatively cheap"... Could be worse...

I'm also kind of interested in how I broke it.

Almost invariably the cause of such things is "belt too tight". When you accelerate or decelerate the various parts of the accessory drive take more or less time to catch up to the crank. This causes the belt to stretch and slack between the contact points...

If its too tight, it binds up and the idlers become the obstacle between the belt proving that old "shortest path between two points is a straight line"...

Now, it could be it was "too tight" because it had momentarily jumped a rib on one of the other pulleys, so you should check your alignment carefully when you put it all back together... laser pen, drywall square, whatever it takes, line up the groves on everything and make sure its all good...

I don't think I misrouted the belt at all but I can't think of what else could have caused this other then that or a defective timing cover. But there has been quite a bit of abuse that it has survived already. The boss is were the bolt screws into correct? If so the whole thing pretty much broke off and is still on the bolt for the idler pulley.

Yes, the boss is the nipple on the timing cover that is threaded... That's exactly what Silverpoison's setup did - just pulled the bolt and a chunk of the timing cover boss right off...

It is more likely the accumulation of abuse and the belt being too tight. When you get it back together, again check the alignment, but make sure the idler has some travel in both directions. You can buy belt tension measuring tools too - that way you'd know for sure that the belt had the right tension.

 

[ZmanM3]

I said "relatively cheap"... Could be worse...


Almost invariably the cause of such things is "belt too tight". When you accelerate or decelerate the various parts of the accessory drive take more or less time to catch up to the crank. This causes the belt to stretch and slack between the contact points...

If its too tight, it binds up and the idlers become the obstacle between the belt proving that old "shortest path between two points is a straight line"...

Now, it could be it was "too tight" because it had momentarily jumped a rib on one of the other pulleys, so you should check your alignment carefully when you put it all back together... laser pen, drywall square, whatever it takes, line up the groves on everything and make sure its all good...


Yes, the boss is the nipple on the timing cover that is threaded... That's exactly what Silverpoison's setup did - just pulled the bolt and a chunk of the timing cover boss right off...

It is more likely the accumulation of abuse and the belt being too tight. When you get it back together, again check the alignment, but make sure the idler has some travel in both directions. You can buy belt tension measuring tools too - that way you'd know for sure that the belt had the right tension.

Accumulated abuse sounds like a possibability. I don't think the belt was too tight as the tensioner was about 1/2 way its travel, not all the way up or all the way down. It broke on crank so I'm woundering if I may have cracked it earlier with my belt problems and it just chose that time to let go. I will make sure of alignment when I get the new cover on though.
Thanks again Mike!

 

[05mustang_TT_charged]

I haven't broke a boss off but I break these pretty often..... See Picture

 

[ChevyKiller]

I said "relatively cheap"... Could be worse...


Almost invariably the cause of such things is "belt too tight". When you accelerate or decelerate the various parts of the accessory drive take more or less time to catch up to the crank. This causes the belt to stretch and slack between the contact points...

If its too tight, it binds up and the idlers become the obstacle between the belt proving that old "shortest path between two points is a straight line"...

Now, it could be it was "too tight" because it had momentarily jumped a rib on one of the other pulleys, so you should check your alignment carefully when you put it all back together... laser pen, drywall square, whatever it takes, line up the groves on everything and make sure its all good...


Yes, the boss is the nipple on the timing cover that is threaded... That's exactly what Silverpoison's setup did - just pulled the bolt and a chunk of the timing cover boss right off...

It is more likely the accumulation of abuse and the belt being too tight. When you get it back together, again check the alignment, but make sure the idler has some travel in both directions. You can buy belt tension measuring tools too - that way you'd know for sure that the belt had the right tension.

Ditto - I think wear has 'some' blame but I think more blame lies in the belt being too tight. I would use a longer belt when you get it back together and adjust from there. I have snapped idlers before and once I snapped an idler bolt right off. Every instance was the belt being too tight. Once I got the proper belt length figured out and replaced most of my idlers with Peter's billet idlers, I never had an issue again.

 

[ZmanM3]

Thats the thing though, the belt really wasn't tight at all. Hmm, I may need to check out Pete's idlers though.

 

[ChevyKiller]

How are you determining the belt is not too tight? If you are simply wrapping your index finger around the belt by the blower pulley and pulling to see how 'loose' it is - you have to account for when you throttle and the tensioner moves and tightens the belt...

 

[ZmanM3]

How are you determining the belt is not too tight? If you are simply wrapping your index finger around the belt by the blower pulley and pulling to see how 'loose' it is - you have to account for when you throttle and the tensioner moves and tightens the belt...

Good point. I was going by the fact that the 110.25" belt with the 2.95" S/C pulley went on easer then the 110.75" belt was with the 3.4" pulley.

The oil is coming from right above where the oil filter screws into the adapter plate that attaches to the engine block. Don't know what that part is called but I think it is going to need to be replaced too. I sure hope it is that and not the block.

 

[ZmanM3]

I'm SO pissed!

We finally got my car buttoned up last night. The timing cover is replaced. I also had to replace the Oil Filter Housing as it got cracked when the idler pulley hit the oil filter. I also replaced the idler pulley that came off with a spare I had as the one that came off was deformed from the impact.

Well after getting everything together we used a lazer level to make sure that all the pulleys were lined up. We tested every pulley to see if it moves freely and then we put the belt on and checked everything again, and again it was straight. The belt looked to be the proper tightness with the tensioner being loaded exactly 1/2 way in its path of travel. We then put the intake tube and filter back on and hooked up the MAF and other wiring.

At this point I got in the car and started it while my friend Mike (who is very knowledgeable Mechanic) watched. Upon cranking the belt promptly snapped. It is obviously binding somewhere but I honestly can't figure out where. I am running the Thrump_rrr tensioner with the 76mm idler pulley on it and the Thrump_rrr belt wrap block for the Saleen S/C. The Idler pulley on the belt wrap block did sustain a gouge last night and I don't know how that happened. I am using the 2.95" pulley with a Gatorback 110.25" belt.

As it was 2230 last night when we tried to crank the car and I was stupid pissed we decided to call it a night and sleep on it. Today I have one more belt and we can put that on and disconnect the fuel and crank it just to see what the belt it doing with out starting it.

Cekim - You said that there are tools you can get to measure if the belt is at the right tension, what tension is it suppose to be at? I would think that if the belt is at a length to put the tensioner at exactly the center of its possible path of travel that it would be the correct length. How many foot pounds of pressure should the Tensioner be providing? This is also something I can check as we do have TQ wrenches available.

Anyway, I would appreciate any ideas anyone can give me. I'll also post some pics when I get by my friends house. He was suppose to email me all the pics we took but never got to it last night so I'll just post them from his computer when I get there today.

 

[ZmanM3]

Another fustrating day

Well today we put the spare 110.25" belt on and then used a ratchet to turn the crank to see if anything was binding and all looked good. We disconnected all the coil packs and used the starter to crank the car so we could see the belt move and all looked good. Then we hooked the coils back up and started it and it promptly broke the belt again.
We then put the 3.4" pulley on with the 110.75" belt (I didn't have any more 110.25 belts) and started it. Good news is I didn't break the belt. Bad news is that the belt is running up over the back of the S/C pulley lip and getting cut and broke between the Thrump_RRR Belt wrap idler pulley and the S/C pulley. I am going to order 2 Thrump_rrr 90mm idler pulleys and take the belt wrap block off. There is only .067mm clearance between the Thrump_RRR belt wrap block pulley and the S/C pulley lip and it seems like the belt is moving in and out as it travels slightly.
I also removed the P/S pulley belt guard as it was all bent up and had 8 rib grove marks on the top of it. Looks like the belt ran up over it at some point.
They belt doesn't walk up at any point other then by the S/C pulley and belt wrap block. The problem is there, how exactly it is causing the problem I'm not sure. I'm hoping that going back to a more stock belt path while allowing belt slip will also solve this problem.

This is were the belt went over the P/S pulley belt guard, this didn't go back on.

The Oil Filter Housing that got cracked.

Broken timing cover

Gouge on the Thrump_rrr belt wrap block idler pulley

This is where the belts left their mark. I had cleaned the pulley before we put it back on.

This is what it looks like with the 3.4" pulley on and the belt on. We didn't break this belt but it too was running up over the lip on the back of the S/C pulley. I think that the Gates belts are a bit stronger then the Goodyear Gator back ones.

One of my newly broken Goodyear Gatorback 110.25" belts.

 

[ZmanM3]

Ok I pulled the trigger on 2x Thrump_rrr 90mm idler pulleys and 1x 76mm Idler pulley. I got the 76mm one just in case the 90mm one doesn't give enough clearance for the belt next to the small Saleen idler pulley under the alternator bracket. The Gripper block is coming off as soon as they get on, hopefully this will fix it.

 

[Freaknazty]

if not i know where they have a twin turbo kit for sale for 6k lmao

 

[ZmanM3]

if not i know where they have a twin turbo kit for sale for 6k lmao

Haha, just not really looking to spend that kind of money right now.

 

[Freaknazty]

just throwing it out there lol hope the new idlers work for ya bud