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Derale 17918: Clutch Fan 18" - JEGS High Performance it was a damn good fan for the two days that it was installed. i almost thought my temp gauge was broken, it ran so cool.
Have you checked your motor mounts maybe since you said that you got on it we always chained Chevy left mount
floored it in first, and the car acted like the belt snapped. shut it off and noticed the waterpump snapped off the block. not sure if the motor moved enough for the fan to dig into the fan shroud, but i'm not sure that would cause this much damage. anyone have any ideas? i'm thinking both mounting arms were already cracked pretty good. View attachment 624500
cc
 

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So what type of motor mounts you running? Are they the TRW ones that are limited in their "movement"?(have a bracket on them that "locks up" and limits engine's movement under hard acceleration. Might want to see if you have one or two broken/separated MMs. That's my theory.
 

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1989 Caprice Classic Brougham
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Discussion Starter · #24 ·
Have you checked your motor mounts maybe since you said that you got on it we always chained Chevy left mount

cc
that's a damn good idea. i didn't even think about it, not sure if it could climb up that much, but i can almost imagine the fan getting caught in the hood before the waterpump broke. only issue is the fan is a good distance away from the hood.
 

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Discussion Starter · #25 ·
So what type of motor mounts you running? Are they the TRW ones that are limited in their "movement"?(have a bracket on them that "locks up" and limits engine's movement under hard acceleration. Might want to see if you have one or two broken/separated MMs. That's my theory.
factory chevy mounts. probably the ones that came on it originally. it was a 305 car. the motor moved a bit while idling, but it wasn't shaking like a wet dog. also no crazy vibrations in the cabin. i'm not sure if they're done yet. i haven't ran it yet since it went down. i guess we'll see if a mount broke under that acceleration
 

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WOW! how many horseys you have? mine just stared to wobble the other day, a 18.00 unit from summit, i called once and the guy said "30 day warranty" didnt seem right to me for some reason, called back and this guy said "lifetime warranty" so they sent me a new one! then i did what i should have in the beginning and looked at the warranty on their site and that also said lifetime warranty.
 

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factory chevy mounts. probably the ones that came on it originally. it was a 305 car. the motor moved a bit while idling, but it wasn't shaking like a wet dog. also no crazy vibrations in the cabin. i'm not sure if they're done yet. i haven't ran it yet since it went down. i guess we'll see if a mount broke under that acceleration
Sounds like you might have just found your problem. I had the TRW mounts on my BBC 396/375 69 Chevelle with Muncie close ratio 4 spd trans and 3:55 Posi with G 60 -15 radials and they never broke. And it wasn't because I wasn't trying............
 

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Any vehicle that came stock with a 305 ( anything 1974-newer) will have clamshell style motor mounts....it is impossible for them to break and let the engine jump around like the earlier style bonded rubber mounts.

It wasn't a motor mount issue that caused this....

Anywhoo....the fan itself isn't strong enough to hit something while spinning and cause a pump to break off....anything underhood in an area the fan could ever hit will either shred the fan on contact or the fan will slice it....the fan is not strong enough to hit something hard, get stopped dead in it's tracks ( es[ecially driven by a rubber belt ) and force the pump to break.

The only object on the front of the motor strong enough and heavy enough to hit and break the water pump is the harmonic balancer.....you'd definitely know if that happened, a 15-20 lb object coming off while spinning....I've seen that happen and it makes 10 times the damage your showing.

i believe it is either cracked rebuilt core, or a imported new casting that was flawed..
 

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Taking a good look at your pictures I see that the shaft broke behind the front pump bearing.

It also appears to have fatigue benches ahead of what looks like a clean break of the shaft.

My suspicions are :
  • A manufacturing error on the shaft resulting from a fatigue in twist of the shaft.
  • Pump cavitation typical of running without a bypass at sustained high RPM before the thermostat has opened. The cavitation shakes tge shaft pretty violently.
  • An out of balance fan or even pulley or the thermo fan controller.
  • Excessive belt tightening putting a bending moment on the shaft, though these things are usually robust enough to take this strain and it shows up in belt stretch.

I hazard the shaft broke for one or more of the above reasons the belts were torn apart as the shaft and fan assembly were parting company, a binding of the belts too place before complete shaft separation which applied more force than the pump casting could resist. Another thought is it started with a belt which got wrapped between the pump and crank pulley jamming everything up.

If this was a rebuilt pump another thought is it went through an accident that micro cracked the attachment horns which eventually grew the crack to failure.

But looking at the wreckage it is pretty apparent that the pump was pulled downward fracturing the mounting horn castings.

Bogie
 

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Discussion Starter · #30 ·
Not sure if this link will work, but it's showing an issue i'm currently facing. i bought a "new" wooder pump, and upon spinning it with, and without the pulley attached, it seems that the pump's hub/shaft is a little crooked. i suspected it was the pulley, but it isn't cracked and it sits flat on a flat surface. spinning just the hub and eyeing it, it looks like the pump's at fault. anyone have an opinion on this? also, as for the two bolts holding the fan clutch on, the clutch was attached to the water pump's hub using two bolts and two studs when i got the car. i couldn't remove the other stud from the previous water pump hub, so it's mounted with one stud and two bolts.

i'm wondering if a little wobble is safe. i'm looking for advice on what to do next.
 

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Discussion Starter · #31 · (Edited)
this isn't very scientific, but here's the hub itself with a ruler.



EDIT: should probably just return it, right? just wondering if the wobble is much of an issue, cause the next one could very well have the same issue.
EDIT2: replaced and wobble is gone. can't even trust new parts. i almost thought i had to get a new pulley
 

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Discussion Starter · #32 ·
update: i thought the original water pump was just junk when it broke . i replaced my rad, fan, water pump, serpentine belt, and coolant. i started the car, bled the system, made sure it ran cool, and it did. it ran great.
shut it off for an hour, came out, started it up. it sounded like the idle was dumb high. i tapped the gas pedal, and my ****ing waterpump exploded, destroying my new rad, and sending my pulley, fan, and clutch out of my engine bay and through my neighbor's fence. my life is a damn cartoon.
 

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Discussion Starter · #33 ·
i assumed the pump was just cheap chinese crap, as other people have, but it seems like my serpentine belt is applying too much pressure to the water pump? the new pump broke in a different way this time. do you guys suppose there's simply too much tension? the car drove for 7-8 days with the original pump before being destroyed, even having floored it previously. this new pump didn't even get put into drive and inched forward without exploding
 

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Is it the same brand from the same supplier as the first one?
If it's the same brand as that wobbly one in the video and the same as the first one, I'd say they are Chinesium junk.
 

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It can't be the serpentine pressure as the spring in the tensioner only puts X amount into the belt, unless the belt is too short and you're using a pry bar to get the belt on.
 

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Discussion Starter · #37 ·
It can't be the serpentine pressure as the spring in the tensioner only puts X amount into the belt, unless the belt is too short and you're using a pry bar to get the belt on.
the original pump is a mystery, and the new one was the same brand as the wobbly one, but it had good reviews. i put the belt on by hand. i just can't imagine that multiple pumps are naturally exploding like this. you don't think it could be installer error as far as belt tension? and to be more specific, this belt was designed for the original 305 in mind, but i'm running the exact same pulley system and accessories. and i did run this motor for a few days in all types of conditions on the original pump before it went out. the only thing that changed on my setup is my oil
 

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Take off the belt and rotate your tensioner back and forth several times to see if there is any weird hard spots. Roll the wheel around a bit to see if it's smooth as silk.
 
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