Can you mount a flywheel wrong?

LarsD

Founding Member
Jul 2, 2002
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Texas
I have a slight vibration and I know I have a 50oz flywheel and blancer. Is it possible that I could have mounted it wrong? My stock clutch fan is really cracked up and old. Could it be causing my vibration? It does in neutral so I know it's not the driveshaft or a tire.

L.D.
 
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LarsD said:
I have a slight vibration and I know I have a 50oz flywheel and blancer. Is it possible that I could have mounted it wrong? My stock clutch fan is really cracked up and old. Could it be causing my vibration? It does in neutral so I know it's not the driveshaft or a tire.

L.D.

No you can't mount the flywheel wrong. Replace the bad fan and go from there. Sounds like you need one even if it's not causing the vibration.
 
LarsD said:
I have a slight vibration and I know I have a 50oz flywheel and blancer. Is it possible that I could have mounted it wrong? My stock clutch fan is really cracked up and old. Could it be causing my vibration? It does in neutral so I know it's not the driveshaft or a tire.

L.D.


I had the same problem as you.. it would be more noticible up around 3K rpm.... the fan was my problem and now it doesnt vibrate at all anymore
 
JIoIE said:
I had the same problem as you.. it would be more noticible up around 3K rpm.... the fan was my problem and now it doesnt vibrate at all anymore

That's just what mine does. Around 2500 to 3000rpm is when I start to notice it. Cool, I was afraid I was gonna have to pull my tranny back out to replace/reposition my flywheel. Would it be OK to drive on it a little while? I want to put an electric fan on my car, but I won't be able to do it for a month or so.

L.D.
 
Fix it.

LarsD said:
That's just what mine does. Around 2500 to 3000rpm is when I start to notice it. Cool, I was afraid I was gonna have to pull my tranny back out to replace/reposition my flywheel. Would it be OK to drive on it a little while? I want to put an electric fan on my car, but I won't be able to do it for a month or so.

L.D.
You are taking a chance that the vibration won't take out the bearing in the waterpump before you fix it. (fan bolted to waterpump, fan shakes=waterpump shakes=kilt pump bearing) Fix it right, fix it once, smile while driving!
 
i would verify that the fan clutch is causing the vibration, although it does sound like it is. simply unbolt the fan clutch from the water pump, bolt only the water pump pulley back on and take a quick drive down the road.
 
DblAdigger said:
You are taking a chance that the vibration won't take out the bearing in the waterpump before you fix it. (fan bolted to waterpump, fan shakes=waterpump shakes=kilt pump bearing) Fix it right, fix it once, smile while driving!

Yeah, your right. Think I'll just put a Flex fan on it until I can get the time to put my electric fan on it.
 
JIoIE said:
a faster way to check is to yank the belt off and rev it up.. Problem should go away

I tried that, and it the vibration went down considerably. My PS pump pulley wobbles a bit (you can see it) and I have a noticable vibration from 2500+rpm. I replaced the fan clutch with a flex fan. Still there, but idles much smoother now. The flywheel looked stock, and it had the counter weight cast into it. How smooth are these engines supposed to run? I don't know how much a difference it makes, but I put convertible mounts on it, and a polygraphite trans mount.
 
I got it, I went out and put my short belt on (bypasing the PS). Actually got to drive the car around. The vibration was gone, car was real smooth, put the regular belt back on, vibration came back. It's that bent pulley. Thanks for the help guys!

L.D.
 
Make sure you get a reverse rotation flex fan if you buy a flex fan. I personally hate them but hey. Also, if you run an automatic, sometimes vibrations are overcome by "Indexing" the torque converter. Meaning, taking the bolts out and moving the converter a bolt hole and reinstalling them. Keep moving it till it helps.