My most embarrassing (and expensive) lesson (1 Viewer)

[raymond2335]

ONE year ago this week I got my 1987 60 2f back from the engine shop. I'm capable and have rebuilt several F engines, but since I was so busy, I decided to let the pros do the work.
It was complete and I only had to put everything back on after bringing it home. (The reason it needed rebuilt was because the keyway in the front of the crankshaft was reamed out. Bad...) So anyways I reassembled everything. Alt, water pump, air conditioning compressor....Etc. Thought I'd done everything to a "T". I drove the truck for a year. Loved it and looked forward to many more. Driving one day, I heard a distinct clunk under load while on the interstate. I shut if off immediately removed the oil pan and there it was.... shrapnel... bits of bearings. Talked to the engine shop and agreed to remove the motor and drop it by for inspection. They told me the front main bearing was galled, possibly spun. I was certain an oil galley was plugged causing the problem. A real head scratcher.... As they dove deeper into the engine, they discovered that a belt... air conditioning??? had been overtightened to the point that it flexed the crank pulley and rubbed against the timing cover..... It had so much torque that it destroyed the front main bearing! It occurred to me that I had a friend helping assemble the motor and he'd used a Milwaukee m-12 ratchet to tighten the belt tensioner on the air-conditioning compressor. I didn't think much of it.... He'll just get it snug and then tighten it to specs right?? No......A real punch in the gut. I'm sick and angry and disgusted at such a careless mistake. If you've made it this far in my story, I hope I can get help finding a crank pully and possibly a crankshaft. It needs ground + 40/1000. So I either need a front main +40/1000 replacement bearing or a fresh unmolested crankshaft. Thanks for listening and don't make the same mistake I did....

 

[duncanrm]

they discovered that a belt... air conditioning??? had been overtightened to the point that it flexed the crank pulley and rubbed against the timing cover..... It had so much torque that it destroyed the front main bearing!

Do you believe this unlikely tale from the shop that built it?

 

[OSS]

The AC belt is thin, very elastic and wimpy. I think it would be very unlikely for that skinny belt to apply enough pressure on the huge crank bearing for it to even notice.
It seems that the AC compressor pulley bearing would blow up instead. It’s tiny in comparison.
Anyway — this just seems so unlikely to me. But I guess it’s possible.

 

[mattressking]

No. The belt would heat and let go or have visual overheating/melting. Plus if over tightened they stretch. If it was installed new and tight, over a year it would loosen, not cause a crank/crankshaft to fail.

They’re playing you, I’ve seen wildly tight alt, power steering v belts and overtightened serp belts, they just stretch.

This was an issue during assembly

 

[65swb45]

Agree with what the others have said. The ‘87 block has a threaded oil galley plug. If it was threaded in an 1/8” too far, it would start to cover the passage to the forward main journal, restricting oil flow.

 

[cruiserpilot]

I've got a story similar. Sorry to hear. If I could help with the crank I'd send it along but around my place
no one keeps them anymore.

 

[Skreddy]

Did they show you that timing cover?
I’ve got to agree with everyone else, sounds like a shop that doesn’t want to foot the rebuild bill.

 

[sark]

Agree with what the others have said. The ‘87 block has a threaded oil galley plug. If it was threaded in an 1/8” too far, it would start to cover the passage to the forward main journal, restricting oil flow.

is this the same oil galley plug that is common to replace before it backs out? how do you know if it was replaced properly/not overtightened?

 

[3_puppies]

I don't think there is that much give to the crank pulley along with the belt not being strong enough to do what they say.
as stated above have them show you the wear marks on the parts

they are trying to blame you for their mistake

 

[AussieHJCruza]

There's no way you could get enough tension on a vee-belt to damage the crank bearings.

Also, you'd be doing alternator/water pump/AC compressor bearings long before the crank bearings.

Sounds like a cop-out from the shop IMHO

 

[roadstr6]

The crank pulley is fastened to the harmonic balancer with rivets. My pulley totally separated itself from the balancer from what I can only imagine was belt overtightening. The rivets literally stretched and the pulley woggled out until it just fell off. No crank damage. Re-furbed the HB and pulley and the truck still lives on. My point here is that the crank is stronger than any belt or pulley on the front of that engine. Your damage was caused by something else.

 

[raymond2335]

ONE year ago this week I got my 1987 60 2f back from the engine shop. I'm capable and have rebuilt several F engines, but since I was so busy, I decided to let the pros do the work.
It was complete and I only had to put everything back on after bringing it home. (The reason it needed rebuilt was because the keyway in the front of the crankshaft was reamed out. Bad...) So anyways I reassembled everything. Alt, water pump, air conditioning compressor....Etc. Thought I'd done everything to a "T". I drove the truck for a year. Loved it and looked forward to many more. Driving one day, I heard a distinct clunk under load while on the interstate. I shut if off immediately removed the oil pan and there it was.... shrapnel... bits of bearings. Talked to the engine shop and agreed to remove the motor and drop it by for inspection. They told me the front main bearing was galled, possibly spun. I was certain an oil galley was plugged causing the problem. A real head scratcher.... As they dove deeper into the engine, they discovered that a belt... air conditioning??? had been overtightened to the point that it flexed the crank pulley and rubbed against the timing cover..... It had so much torque that it destroyed the front main bearing! It occurred to me that I had a friend helping assemble the motor and he'd used a Milwaukee m-12 ratchet to tighten the belt tensioner on the air-conditioning compressor. I didn't think much of it.... He'll just get it snug and then tighten it to specs right?? No......A real punch in the gut. I'm sick and angry and disgusted at such a careless mistake. If you've made it this far in my story, I hope I can get help finding a crank pully and possibly a crankshaft. It needs ground + 40/1000. So I either need a front main +40/1000 replacement bearing or a fresh unmolested crankshaft. Thanks for listening and don't make the same mistake I did....

ONE year ago this week I got my 1987 60 2f back from the engine shop. I'm capable and have rebuilt several F engines, but since I was so busy, I decided to let the pros do the work.
It was complete and I only had to put everything back on after bringing it home. (The reason it needed rebuilt was because the keyway in the front of the crankshaft was reamed out. Bad...) So anyways I reassembled everything. Alt, water pump, air conditioning compressor....Etc. Thought I'd done everything to a "T". I drove the truck for a year. Loved it and looked forward to many more. Driving one day, I heard a distinct clunk under load while on the interstate. I shut if off immediately removed the oil pan and there it was.... shrapnel... bits of bearings. Talked to the engine shop and agreed to remove the motor and drop it by for inspection. They told me the front main bearing was galled, possibly spun. I was certain an oil galley was plugged causing the problem. A real head scratcher.... As they dove deeper into the engine, they discovered that a belt... air conditioning??? had been overtightened to the point that it flexed the crank pulley and rubbed against the timing cover..... It had so much torque that it destroyed the front main bearing! It occurred to me that I had a friend helping assemble the motor and he'd used a Milwaukee m-12 ratchet to tighten the belt tensioner on the air-conditioning compressor. I didn't think much of it.... He'll just get it snug and then tighten it to specs right?? No......A real punch in the gut. I'm sick and angry and disgusted at such a careless mistake. If you've made it this far in my story, I hope I can get help finding a crank pully and possibly a crankshaft. It needs ground + 40/1000. So I either need a front main +40/1000 replacement bearing or a fresh unmolested crankshaft. Thanks for listening and don't make the same mistake I did....

Update. Stopped by the engine shop today to view the crank pulley, timing cover, block and crankshaft. Sure enough, the crank pulley and timing cover are damaged. The seal in the timing cover is fine and was not leaking oil when I pulled the engine. but the end of the crankshaft rubbed against the inner wall of the timing cover and did a number on it. I will either need a sleeve or a replacement triple crank pulley. I also snapped a picture of the front main cap that was discolored from heat. I still refuse to believe that over tensioned belts caused this. For starters, I’ve got three belts running off that front main pulley. All pulling different directions. Wouldn’t that even out the pressure somewhat? Regardless, at this point, the damage is done. I bought an older 2F from a friend that was sitting in his garage. This crankshaft is going to need some touching up and likely 20 over bearings on the mains and pushrods. (It’s at +10 now). They are still assessing the damage caused by the “over tightened belts“ to the block and front main cap. Only the front main was damaged. Hopefully this latest crankshaft checks out. Will post updates. .

 

[3_puppies]

couple things,
that much heat is a lack of lubrication, oil flow
which direction is the timing cover damaged? if the shop installed the timing cover first without the crank pulley installed to self center the cover, the groove in the pulley will occur.

a belt being over tightened will not cause this damage.

 

[BurntToast]

I wouldn’t trust a shop that says that the pulleys caused this IMO

 

[CruiserTrash]

couple things,
that much heat is a lack of lubrication, oil flow
which direction is the timing cover damaged? if the shop installed the timing cover first without the crank pulley installed to self center the cover, the groove in the pulley will occur.

a belt being over tightened will not cause this damage.

I'm currently building a spare 2F and wanted to ask a question about this...

The oil seal on the timing cover rides on the inside of the crank pulley, is that right? Since the timing cover can't possible fit over the pulley, put the cover on first, throw a few bolts in it to keep it in place but keep the bolts loose, push the crank pulley onto the crank & key, then snug up the timing cover, and finish with the big crank nut? I haven't gotten to this area yet and this is my first rodeo so I keyed in on your little tidbit here. Thanks.

 

[3_puppies]

I'm currently building a spare 2F and wanted to ask a question about this...

The oil seal on the timing cover rides on the inside of the crank pulley, is that right? Since the timing cover can't possible fit over the pulley, put the cover on first, throw a few bolts in it to keep it in place but keep the bolts loose, push the crank pulley onto the crank & key, then snug up the timing cover, and finish with the big crank nut? I haven't gotten to this area yet and this is my first rodeo so I keyed in on your little tidbit here. Thanks.

correct, install cover loose, install crank pulley, there is enough play in the holes to self center the cover, then tighten all
keeping the correct bolts in the correct places around the timing cover, there are a few different lengths of bolt they need to go in the correct places.
also be cautious when installing the timing cover seal, damage can be done to the timing cover

 

[MarkMarine]

I'm a mechanical engineer, so this is just theory:
The force the belt imparts on the pulley is a factor of the wrap angle, preload force, the belt speed, and the forces on the tight and slack side of the belt. Essentially it'll collapse down to one vector, basically in the direction you would think (pointed towards kind of the middle of the two accessories powered, but closer to the tight side)

Multiple belts would have vectors that combine in certain directions and cancel out in other directions, again kind of in the way you'd imagine...

but... the force v-belts could impart on a bearing is comically small compared to the other forces on the main bearings. There is just no way you could have tightened v-belts enough to harm the main bearings. Sounds like an oil galley was plugged, they didn't clean the block well enough, or something else starved that main bearing, and the people at the machine shop are reaching for anything they can to push the blame on to someone else.

 

[65swb45]

I'm a mechanical engineer, so this is just theory:
The force the belt imparts on the pulley is a factor of the wrap angle, preload force, the belt speed, and the forces on the tight and slack side of the belt. Essentially it'll collapse down to one vector, basically in the direction you would think (pointed towards kind of the middle of the two accessories powered, but closer to the tight side)

Multiple belts would have vectors that combine in certain directions and cancel out in other directions, again kind of in the way you'd imagine...

but... the force v-belts could impart on a bearing is comically small compared to the other forces on the main bearings. There is just no way you could have tightened v-belts enough to harm the main bearings. Sounds like an oil galley was plugged, they didn't clean the block well enough, or something else starved that main bearing, and the people at the machine shop are reaching for anything they can to push the blame on to someone else.

I think that EVERY SINGLE POSTER to this thread has agreed unanimously that the belts did not cause this problem. ONLY the O.P., who didn’t actually post looking for our opinions, believes otherwise.

I find it cosmically interesting that this was posted in Chat 20 minutes ago:

 

[duncanrm]

I think that EVERY SINGLE POSTER to this thread has agreed unanimously that the belts did not cause this problem. ONLY the O.P., who didn’t actually post looking for our opinions, believes otherwise

The OP has stated in a follow up :

I still refuse to believe that over tensioned belts caused this.

 

[raymond2335]

ONE year ago this week I got my 1987 60 2f back from the engine shop. I'm capable and have rebuilt several F engines, but since I was so busy, I decided to let the pros do the work.
It was complete and I only had to put everything back on after bringing it home. (The reason it needed rebuilt was because the keyway in the front of the crankshaft was reamed out. Bad...) So anyways I reassembled everything. Alt, water pump, air conditioning compressor....Etc. Thought I'd done everything to a "T". I drove the truck for a year. Loved it and looked forward to many more. Driving one day, I heard a distinct clunk under load while on the interstate. I shut if off immediately removed the oil pan and there it was.... shrapnel... bits of bearings. Talked to the engine shop and agreed to remove the motor and drop it by for inspection. They told me the front main bearing was galled, possibly spun. I was certain an oil galley was plugged causing the problem. A real head scratcher.... As they dove deeper into the engine, they discovered that a belt... air conditioning??? had been overtightened to the point that it flexed the crank pulley and rubbed against the timing cover..... It had so much torque that it destroyed the front main bearing! It occurred to me that I had a friend helping assemble the motor and he'd used a Milwaukee m-12 ratchet to tighten the belt tensioner on the air-conditioning compressor. I didn't think much of it.... He'll just get it snug and then tighten it to specs right?? No......A real punch in the gut. I'm sick and angry and disgusted at such a careless mistake. If you've made it this far in my story, I hope I can get help finding a crank pully and possibly a crankshaft. It needs ground + 40/1000. So I either need a front main +40/1000 replacement bearing or a fresh unmolested crankshaft. Thanks for listening and don't make the same mistake I did....

I agree with the consensus, the belts could not have caused this damage. I’m not foolish, but also open to ideas While at the machine shop the other morning, I asked him if he’d ever seen this sort of thing caused by overtightened belts. Of course he said certainly. I floated the idea that 65swb45 posted. The oil galley plug overtightened was a possibility of restricted oil flow. He shot that theory down. Here’s the deal, this machinist is 77 years old. He’s been battling cancer and all sorts of health issues. He’s an old friend and has 50 years experience with motors. That’s not to say he didn’t have something to do with the engine failure. Odds are all for it. I’m just floating some ideas to him and made it very clear. He is the only one who has had his hands in this engine. I don’t want the same thing happening again.
My question to anybody brave enough to still be a part of this conversation, what would cause the damage to the front pulley and timing gear cover? Something isn’t adding up.
At this point, I am 100% certain of what did not cause the damage. Next time I’m at the machine shop, which is 40 miles away incidentally, I’m going to snap pictures of all damaged parts and keep everybody posted