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Strong vibration gets worse at high rpm

Hi guy's,

Need advice on this one.

A mechanic (not my friend anymore after a lot of stupid things)
put in a new Sachs clutch and flywheel.
But there is a strong vibration at 4000 rpm and gets worse at higher rpm
If the car is at idle it does not appear. It's only when the car accelerates to higher rpm.
once the vibration starts you need to release the clutch pedal to stop the vibration. If you drive the car at low Rpm all is normal.
It's not speed related. The vibration is very strong, even chassis is making noise.
I changed tranny mounts.
Any suggestions?
Old 09-23-2013, 05:39 AM
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I had a loose engine mount bolt that rattled the whole car at some RPM points. I was lucky I went investigating.
I believe the torque is 68lbs on each of those four mounts. Loosen them all, let the drivetrain sit where it wants to sit, and then retorque?
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Old 09-23-2013, 06:31 AM
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Deleted-double post
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Last edited by gsxrken; 09-23-2013 at 07:11 AM.. Reason: Duplicate post
Old 09-23-2013, 06:33 AM
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two things I have seen:

-No centering tool was used for disc when assembling the pressure plate

-On modified flywheel some genious machined away the centering flange for the pressure plate
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Old 09-23-2013, 06:42 AM
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Quote:
Originally Posted by proffighter View Post
two things I have seen:

-No centering tool was used for disc when assembling the pressure plate

-On modified flywheel some genious machined away the centering flange for the pressure plate
I hope it's not the last one because they told me first that they ordered the wrong flywheel, it was just touching somewhere around the engine case. they are capable doing something like that!

I will check it!
Is it possible to see if no centering tool was used?
If I remove the engine and can't find anything would be a pain in the as ...
Old 09-23-2013, 07:33 AM
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Wouldn't the clutch disk self center after use and be fine afterword? Provided you can get the trans and engine together if not centered. I doubt this as a source for vibration.
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Old 09-23-2013, 07:40 AM
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Quote:
Originally Posted by gsxrken View Post
I had a loose engine mount bolt that rattled the whole car at some RPM points. I was lucky I went investigating.
I believe the torque is 68lbs on each of those four mounts. Loosen them all, let the drivetrain sit where it wants to sit, and then retorque?
That's what i'm going to do first!

Update:

When i'm driving 70 in 3 gear without vibrations and push the clutch the car starts vibrating to. not that strong bud easy to feel and hear... at this point (so with clutch pedal loose) I tried to push the accelerator and then it's also vibrating strong!

mmm hard to explain if it's not your language! hope you guy's get me!
Old 09-23-2013, 07:44 AM
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Quote:
Originally Posted by quattrorunner View Post
Wouldn't the clutch disk self center after use and be fine afterword? Provided you can get the trans and engine together if not centered. I doubt this as a source for vibration.
firt of all ,Congrets posting 3000 times

Maybe the plate get's damaged while installing without centering the plate
Old 09-23-2013, 07:51 AM
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Quote:
Originally Posted by klefroid View Post
firt of all ,Congrets posting 3000 times

Maybe the plate get's damaged while installing without centering the plate
Hmmm, well yeah I guess I can see that as a possibility. You'll have to separate to look. I had a heck of a time getting the trans and engine together when I couldn't find my $7 centering tool once. I had to fashion one to better center it or it just plain would not mate up. A tiring and physically draining deal for me. Once centered it just worked.
Thanks, Interesting observation
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Old 09-23-2013, 08:06 AM
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That bar is touching my tranny...???
Could this cause vibrations?
While checking engine mounts it catched my eye?



Old 09-23-2013, 08:15 AM
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The bar is the swaybar. It wouldn't cause the vibration you speak of.
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Old 09-23-2013, 08:25 AM
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Quote:
Originally Posted by quattrorunner View Post
The bar is the swaybar. It wouldn't cause the vibration you speak of.
Well... maybe. The clutch and flywheel is what changed so they are suspect #1 and #2, but anything touching the engine could feed engine vibration and noise into the chassis.
Theoretically the engine and trans is isolated by rubber mounts at the rear engine mounts and the trans mounts. The shifter has a coupler that's supposed to take up some feedback too. If his sway bar is resting on the trans for some reason, that's a direct path to the chassis, especially is he has some Tarrett, Smart Racing or other hard mounted bars. Under load and then no load, things shift and he may be all over that sway bar. I'd address it either way. Quick dx would be to remove it, test drive and see if problem persists.
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Old 09-23-2013, 09:31 AM
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I had translated the vibration to more of a shake. I might be wrong.
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Old 09-23-2013, 10:38 AM
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Update:

When I drive in 3 gear 60 mph (at this point no vibration) then go to neutral (still no vibration)
but then when I push clutch pedal you can feel light vibration ,when I go to second gear the vibration gets worse ,this is without releasing the pedal.
Is there a bushing or a bearing on the flywheel where the axle from the tranny goes in?
Maybe they forgot to put it in or maybe the wrong one... Could this cause that strange vibration?

edit: Swaybar doesn't touch anymore so that's fine but did not help it.

Last edited by klefroid; 09-24-2013 at 09:23 AM..
Old 09-24-2013, 08:59 AM
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There is a replacable bearing in the center of the flywheel the end of the transmission input shaft slides into. It's called the pilot bearing. Most people replace it and the clutch throwout bearing when servicing the clutch.

If there's a problem with it you would most likely hear a grinding noise from it while idleing when parked with the transmission in gear and the clutch pedal pushed in.

Does this car have the origonal rubber center clutch disc? Thats another awful design in these cars. The rubber dries out and cracks and pieces of rubber fly off and then the clutch disc is out of balance if it still works at all.
Thats probably not the problem but you should always replace the clutch disc with a spring center disc that also cost less than the rubber one.

Also, do the rear axles and everything else stay centered when the car is up on jackstands or a lift while the engine is running in gear while the rear wheels are spinning? If not they or something is probably bent.

Are all cylinders pretty much equal in compression and leakdown so they are putting out equal power? If not that can cause some vibration when accelerating.
Old 09-24-2013, 11:25 AM
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Quote:
Originally Posted by JFairman View Post
There is a replacable bearing in the center of the flywheel the end of the transmission input shaft slides into. It's called the pilot bearing. Most people replace it and the clutch throwout bearing when servicing the clutch.

If there's a problem with it you would most likely hear a grinding noise from it while idleing when parked with the transmission in gear and the clutch pedal pushed in.

Does this car have the origonal rubber center clutch disc? Thats another awful design in these cars. The rubber dries out and cracks and pieces of rubber fly off and then the clutch disc is out of balance if it still works at all.
Thats probably not the problem but you should always replace the clutch disc with a spring center disc that also cost less than the rubber one.

Also, do the rear axles and everything else stay centered when the car is up on jackstands or a lift while the engine is running in gear while the rear wheels are spinning? If not they or something is probably bent.

Are all cylinders pretty much equal in compression and leakdown so they are putting out equal power? If not that can cause some vibration when accelerating.
This is very helpful!
The car doesn't have the original rubber center clutch disc. all is new.
engine is running fine, I'm shore about that.

I wil lift the car to check on that one!
But I think this would not be the problem because then it would happen when I accelerate very slow to high rpm. that's not the case.

They put in a later model clutch kid and adapter.
Where I'm thinking of is, maybe the pilot bearing inner center is to big for the shaft... Would this be possible? or maybe the did not use the pilot bearing at all!
they did a lot of stupid things with my lovely car! I would not be surprised about that!

Thanks for your input all of you.

Last edited by klefroid; 09-25-2013 at 08:23 AM..
Old 09-25-2013, 08:19 AM
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I had a slight vibration that turned out to be incorrectly installed motor mount concave washers - they were installed upside down. Another strike against my previous mechanic unfortunately, but an easy fix for the current mechanic who figured it out pretty quickly when he drove it!
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Old 09-26-2013, 04:49 PM
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Are these installed correct?
You see that wire? thanks mechanic :-) Does someone know where this wire needs to go?

Last edited by klefroid; 09-26-2013 at 09:01 PM..
Old 09-26-2013, 08:59 PM
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This thing makes me nuts! No problem to drop the engine but can not do it myself because I do not have tools to do it... Don't want to drop the engine unnecessary ... even when I'm in neutral driving 50 mph, no vibration and when I get any gear vibration starts, even without letting go the clutch...
Old 09-27-2013, 02:06 PM
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The only thing that is changing going from neutral to being in gear is that you are spinning up the input shaft and clutch disk. It really sounds like you have a problem with the pressure plate, maybe a chunk of friction material broke loose, or their is something wrong with the spring/hub assembly.

Also, the parts diagrams show that you should have the large metal washers above and below the rubber part of your engine mounts. In your picture, it looks like you don't have them below.
Old 09-27-2013, 02:44 PM
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