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914World.com _ 914World Garage _ Shuddering badly

Posted by: Ctrout Feb 12 2005, 11:37 PM

My car recently developed a severe shudder and I can't figure it out. It feels like the back end of the car is going to explode or something. It happens when letting out the clutch from a stop in first gear. It doesn't happen when the car is cold, only after it has had a few minutes of driving to warm up. If I rev a bit higher than normal, it doesn't do it. Everything is normal with the car's function except this strange problem. The clutch was replaced about 4 months ago along with the trans shaft seal and rear main seal. I put a jack in the middle of the engine and jacked it up. the car came up with the motor so I think the mounts are fine. Any ideas?

Posted by: McMark Feb 12 2005, 11:52 PM

Motor mounts.

Posted by: wrpspddrvr Feb 13 2005, 12:35 AM

Hmmm. Try starting in a lower gear.

Seriously, maybe it's clutch chatter? You don't hear about it as much in lower HP cars, but...?

Cole

Posted by: markb Feb 13 2005, 12:45 AM

Have you readjusted the clutch since installation? You might try that.

Posted by: Lou W Feb 13 2005, 01:24 AM

My guess is clutch

Posted by: Aaron Cox Feb 13 2005, 01:27 AM

sounds like clutch chatter

Posted by: Ctrout Feb 13 2005, 01:33 AM

I adjusted the cluthch a few days ago. Didn't help. So what is clutch chatter and how do I fix it? I thought bad motor mounts would be evident when performing the jack test as I mentioned above. Does this not always work? "from a stop in first gear" Is ther a lower gear than first? The feeling when this happens is more like wheel hop than chatter.

Posted by: Lou W Feb 13 2005, 01:41 AM

I replaced a clutch on a previous car that I owned, I was told that I should look at the flywheel and pressure plate surfaces to make sure that there were no cracks, hot spots or warped areas. These could cause the clutch disc to chatter when engaging or disengaging the clutch. Oh yah, and fluid leaks too.

Posted by: Brando Feb 13 2005, 03:06 AM

motor mounts, trans mounts, clutch needing adjustment/replacement, flywheel in poor condition... all mentioned above ^

Mine's been doing this too. Just take it easy, don't pop the clutch and try to take off super-fast. i've done that to break the tyres loose, i think i accelerated the decay of my car's clutch... but i made the tyres squeal!

Only way you can really be certain, is to drop the engine and trans, separate the two, and inspect your clutch and flywheel. This may also be a sign that your clutch is on it's way out.

Posted by: Aaron Cox Feb 13 2005, 12:04 PM

ive heard that the CV's can make this noise...

Go Check Your CV Joints

Posted by: r_towle Feb 13 2005, 01:18 PM

motor mounts where the bar attaches to the engine...

If those get loose, which they tend to, it will shudder.
It smooths out at higher reves because the engine balances out....
If it was a flywheel balance issue or clutch issue you would feel it even more at higher revs.
Plus tranny mounts....Look at it this way, the motor was removed and reinstalled 4 months ago...have you retightened all the bolts sisnce that happened???You should on any normal removal and reinstall anyways.

Rich

Posted by: ! Feb 13 2005, 01:25 PM

mounts...BOTH motor and transmission.....if renewing them does not correct the chatter...they prolly needed to be replaced anyways. They are a cheap fix and make the car more driveable.....

Posted by: aircooledboy Feb 13 2005, 01:29 PM

QUOTE (r_towle @ Feb 13 2005, 01:18 PM)
If it was a flywheel balance issue or clutch issue you would feel it even more at higher revs.

No, I don't think so man. Only does it when starting out in 1st gear. This is almost certainly a clutch problem. Clutches chatter because the pressure plate is not evenly contacting the disk as the clutch is let out , usually because either the p plate or the fly wheel has worn. It is not a balance problem, but an uneven contact/ uneven grabbing problem. Once the pedal is released, the disk is no longer moving between the p plate and the fly. That is why it stops chattering.

Posted by: r_towle Feb 13 2005, 01:49 PM

If that were true, it would shutter whenever you re-engage the clutch.

motor mounts and tranny mounts

Posted by: Brando Feb 13 2005, 02:18 PM

Wait, who makes aftermarket engine and trans mounts? How much for new or OEM?

Posted by: Aaron Cox Feb 13 2005, 04:12 PM

i have solid trans mounts...and stock rubber engine mounts....

Posted by: aircooledboy Feb 13 2005, 04:14 PM

QUOTE (r_towle @ Feb 13 2005, 01:49 PM)
If that were true, it would shutter whenever you re-engage the clutch.

motor mounts and tranny mounts

My V8 was doing exactly what Ctrout describes. Always when letting the clutch out, never when putting it in. On tear down, I found I had a warped p plate. It doesn't chatter putting clutch in because there is no load on it.

Posted by: redshift Feb 13 2005, 04:18 PM

Has your car recently seen a picture of mikez's ass?

That causes shuddering... oh yeah.

I say it's in the clutch rig, and I tend to think there is a warped pp too, because with it fully engaged, it doesn't shudder, right?

If it had seen a picture of mikez's man cleavage... I'd say it needs an acid dip..

If you haven't changed the mounts, it's worth doing!

M

Posted by: redshift Feb 13 2005, 04:19 PM

QUOTE (Brando @ Feb 13 2005, 04:18 PM)
Wait, who makes aftermarket engine and trans mounts? How much for new or OEM?

I lost the number, but seanery gave me a line on solid mounts for cheap..

M

Posted by: Ctrout Feb 13 2005, 06:57 PM

I'll start with the mounts when I find some and get the ambition up to do the work. If it ends up being the pressure plate, I'll be surprised. I wouldn't think it would have gone bad so suddenly and after only 4 months of driving.

Posted by: Ctrout Feb 26 2005, 10:17 PM

I finally made the time to get under the car to adjust the valves and do an oil change today. While I was under there, I found out why it was shuddering. I didn't need new motor mounts or a new clutch. I needed to tighten the engine to trans nuts that had backed nearly all the way off! Guess I should look into lock-tighting or safety-wiring them. I retightened the bolts, finished up the other stuff and took it for a test drive. Smooth as butter!

Posted by: Brando Feb 26 2005, 10:46 PM

You sort of got lucky there

I still have to buy myself a set of motor and trans mounts