vibration after clutch and pressure plate replacement

grayback

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Nov 27, 2020
Location
NW Ohio
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2005 jetta
2005 jetta tdi BEW wagon. I just had the 230mm clutch, pressure plate, dual mass flywheel, and release (throwout) bearing with the bearing slide tube replaced with the Sachs kit. On the test drive the clutch seemed to engage and disengage smoothly. The noise when the transmission was out of gear and the motor was running with the clutch disengaged (the original problem) was gone. But, when driving the car there was a severe vibration at 1,800 to 2,300 rpm, worse under acceleration. It could be felt throughout the car even in the seat, but not through the shifter. The motor mount on the driver side was replaced with an ECS Tuning mount the week before. It feels like driveline vibration. Any ideas?
 
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Franko6

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May 7, 2005
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Sw Missouri
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Jetta, 99, Silver`
You went to a single mass flywheel? Where did the clutch kit come from? What did the flywheel face look like? There is a joke out there of a Eurospec clutch we have renamed as a Chinaspec clutch. It's not flat, it's not balanced, and the face was turned on a lathe instead of true'd up on a flywheel surfacer.

The other issue we often see is that the distance from the ring gear to the flywheel contact surface is shorter than it should be, some as short as .460" It should be closer to .500" With the closer dimension, the disc can drag and warp either the disc or the flywheel and cause hot spots.

About 3 years ago, we started in balancing and surfacing 'good' flywheels, because on the average 12, two of them are balanced. On one, the flywheel was drilled 180 degrees out! Most are 2.4gr out of balance. The worst was 12.4 gr. 0.0 is the correct number.

The other thing that seems to happen is the flywheel face is not always flat to the contact surface on the crank. There are occasions that the surface will cut out of square. That will sure make it vibrate.

Other than that, we have had people who thought their flywheel was not balanced and we balanced their injectors. That was an eye-opener. He thought it was the clutch and it ended up being misbalanced injectors. Check VCDS, Engine Module/ Measurements/ Block 13 idle balance compensation and block 15 liter per hour fuel usage. Check at Idle and at 1575rpm. You are looking for block 13 to show numbers as close as possible to 0.00 mg/str. If you are out +/- 1.0, you need to do something about your injectors. Run a diesel purge bypassing the fuel filter. That always seems to help the fueling numbers.

Fuel filter? dead lift pump? Check fuel flow, to tandem pump, as that can cause engine misfires.
 

Tdijarhead

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Nov 10, 2013
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Lawrenceville PA
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2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Daughters car, 2005 Golf TDI Mine, all 5 spds
Are the 6 bolts that hold the inner cv joints to the flange tightened properly?
 

grayback

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Nov 27, 2020
Location
NW Ohio
TDI
2005 jetta
Frank, Dual mass flywheel. Kit manufacturer- Sachs. Seller-Pelican Parts. There was no vibration prior to the clutch work. Injector issue is a long shot. We will have to take it apart to check the flywheel.
Tdijarhead, Will check the cv joints.
Thanks to both of you
 

jlav0330

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Jan 5, 2020
Location
SoCal
TDI
2003 Golf
You might not have reinstalled the transmission mount correctly? I noticed a vibration when I replaced my clutch too earlier this year, but I wouldn't call it "severe". It was more annoying than anything. You might want to go inspect your mount again to make sure that where the bolts are now are where they were at before. You can typically see where the bolts were rested, there will be discoloration on the top. When I eventually got a new mount a few months later and went to change it, I saw that the mount was twisted, and remembered that when I was jacking up the transmission when doing the clutch, it was coming in at a weird angle, and I tightened it down like that. Check it out and let us know!
 

KrashDH

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Dec 22, 2013
Location
Washington
TDI
2002 Golf
I'd put my vote in for one of the mounts not getting tightened down correctly. It's amazing the vibrations you can get when one is loose or worn, Check the dogbone, transmission mount, transmission adapter mount, as well as the metal black cross brace on the top. Those could all contribute

It's not flat, it's not balanced, and the face was turned on a lathe instead of true'd up on a flywheel surfacer.
@Franko6, do you surface grind your flywheels? What flatness are you achieving on the mating face to the crank shoulder and parallelism of the opposite (pressure plate surface)? Or do you only do the pressure plate side? I'm just wondering because it would take a real hack to not be able to turn that pressure plate side down to within a couple thou of parallelism to that mating side on a lathe. But then again it depends on the machine and the setup. But, you'd have to be REALLY good on a lathe to get the right surface finish out of it. I'm under the assumption the grind is only necessary to achieve surface finish. Sounds like you've seen a few that have been chucked crooked on a lathe with worn gears, sloppy bearings, and mounted on a hill!😂
 

Franko6

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May 7, 2005
Location
Sw Missouri
TDI
Jetta, 99, Silver`
Grayback,
Dual mass flywheels cannot be resurfaced. Also, I've never attempted to balance one, as we do not build with them.

I may have misunderstood your rpm range. If you were in top gear, doing 45-50, that is where axle vibrations are most prominent, normally. Check each axle end and that the inner axle is mounted squarely and the grease seal, if any, is properly located. One thing we see a lot are aftermarket right side axles that are a solid shaft, where the OEM right axles are tubes. The Chinese axles are prone to vibrate.

Injectors are not as remote as you might think. We have seen a low-fueling or excessive fueling injector set up a vibration, but I will agree, it's more likely axle, or something could have gotten behind the flywheel on the crankshaft.
 

Franko6

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Sw Missouri
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Jetta, 99, Silver`
KrashHD,

The machinery we use has a carbide indexable cutter that cuts from the outside edge of the disc contact area to the inside edge. One complete circle, and the flywheel is surfaced, with runout less than .0005". We do not do the pressure plate side. Only the flywheel side, as that is usually where the issue crops up for quality of surface, flatness, depth from ring gear to flywheel face and balance. These are all issues.

A lathe would not be as good a method, nor would I recommend trying that. To lathe cut the face will double the opportunity for run out.

I think the problem with how the flywheels are made is the same old problem. Lack of quality control. I have the opinion that when balancing, the locations is found, the amount registered, but once drilled, we think they do not recheck their work. That would take an additional 15 seconds. Also, the attention to detail... no matter how good the machine, it's only as good as the operator. If any debris is under the mating surface of the machine or the flywheel, the cut will be out of parallel.

We have seen a variety of workmanship and styles of flywheels. Some are better than others, but none we have seen are perfect. We try to make them that way.
 

wonneber

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2014 Jetta Sportwagen, 2014 Tiguan,2003 Jetta 261K Sold but not forgotten
Run a diesel purge bypassing the fuel filter. That always seems to help the fueling numbers.
Frank,
Any reason bypassing the filter?
I would think the filter might help trap any particles in the purge supply.
I used a small lawn mower filter when I purged my 03 JSW years ago.
 

jmodge

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2001 alh Jetta, RC2 5speed daily commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/502's backroad cruiser
I think he meant the stock filter and use a separate one as you did
 

Franko6

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May 7, 2005
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Sw Missouri
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Jetta, 99, Silver`
Wonneber, I have always bypassed the tank filter so there is less dilution for the purge. I like to use it full strength. Sorry, but I did not mention it... I agree, the use of a small in-line filter on the hose coming out of the purge can, going to the tandem pump is a necessary. We often see debris coming back to the purge can from the return line. So, 1. You know the purge is doing job and 2. you don't want any debris going back into the injectors.

Another thing we have incorporated, is the use of two cans of purge, separated by a complete engine cool-down between cans. The thought is that giving the engine some time to let the parts cool allows the purge to crack some more crap off of the parts.

As for the vibration, It was never clear to me, and I asked, was the rpm related to the miles per hour to make the vibration, or was it only engine speed. I certainly agree, if it's related to road speed, it's something to do with the axle, wheel or tire.

I have a notion to check the balance of a dual mass flywheel (DMF), as we do occasionally install those against DSG transmissions. It's not something we will ever do for a DMF on manual transmissions. I think the Single Mass Flywheel (SMF) discs with the larger springs and Exedy hub are better and longer lasting when attached to a SMF that is balanced and properly surfaced, than any DMF. Driving style and purpose have a lot to do with it.

The reason we find great flywheel balance important is not that it will make the clutch feel smoother. Most of the times, you can hardly detect the flywheel's out-of-balance (OOB), but it will protect the main bearings from the oscillation created by an OOB flywheel. The deeper studies are considering Noise Vibration Harshness (NVH), and everything from imbalanced pistons/ rods/crank/ crank distortion/ torsion loading, etc., etc. will make cylinder head flow calculations look easy. We aren't trying to balance a V-12 Bentley engine with it's double throw V-90 dual VR6 piston pattern. I have considered that insanity and wonder if they even got close; counterbalances and all.

At an early age, I had a 396 Ford that the machinist told me the flywheel was 3 oz OOB. Considering the size of the flywheel, I said,"That's not much." If looks could kill... The machinist said,"That 3 oz. turns into 3 pounds at 2,000 rpm!" The physics of dynamics. At the 8,000rpm we were wanting to turn, and you can imagine, the OOB weight exponentially compounds to ridiculous numbers; sometimes hundreds of pounds of OOB. When you start down the rabbit hole of balance, things get insane, even calculating ring drag and rod rotation circle.

Fortunately, with the lower engine speed and the simplicity of a 4 cylinder engine we generally work with, balancing can be simplified to some basic roots. Reciprocating mass. Overall balance. No counter-balance weighting to contend with. What we generally contend with is very basic and simple. We always balance our flywheels. We always balance our pistons and rods. And I can tell you.. When it came to piston/ rod weighting as VW did it, they did not care. As Sachs and many others have done flywheels, 1/4oz on a 21lb flywheel is way too much, especially if you expect to run over 5000 rpm.

If you do want to check your flywheel, I can do so. Matter of fact, our balanced flywheels are cheaper than what many price for 'off the shelf', 'untested' components. And if you ever see a flywheel that is cast and has no drill marks, you are looking at one of the very cheap flywheels; not balanced at all.
 

PakProtector

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Jan 5, 2014
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Mk.4 and the Cummins-es
Awe crap...now that some of y'all are putting numbers on this, I have to jump in with corrections. Out of balance force is not an exponential thing with rpm...it is simply square of revolution rate, and distance away from center. This is why balance specs are mass-distance numbers. gram-millimeter for small fast stuff, and going up from there.

F=m*a

a is radians per second-squared*distance from rotational center.
add the m(-ass) and we get force.

Now I went and looked at a Sachs VR6 pressure plate and that friction surface is most certainly turned on a lathe. I did not pull the SMF flywheel out of its bag so I'll not comment on what created the surface finish there; it is smoother than the PP though.
cheers,
Douglas

balancing inline engines is relatively easy; try a 3350ci, 18 cyl, 2-bank radial...or perhaps a bigger 4-bank.
 
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wonneber

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Oct 12, 2011
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Monroe, NY, USA
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2014 Jetta Sportwagen, 2014 Tiguan,2003 Jetta 261K Sold but not forgotten
Well I guess I opened a can of worms. :)
Guess I've been lucky with the few flywheels I've replaced over the years.
Only replaced one DMF in my old 03 JSW and did not notice any problem.
 
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grayback

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Nov 27, 2020
Location
NW Ohio
TDI
2005 jetta
Thanks to all. It was the new motor mount. We took it off and replaced it with the old one. Vibration gone. ECS obviously sent me the wrong mount. The clutch pedal seems to engage down closer to the floorboard than before. Is there an adjustment for the pedal. I thought hydraulic clutches were self adjusting.
 

KrashDH

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Dec 22, 2013
Location
Washington
TDI
2002 Golf
Thanks to all. It was the new motor mount. We took it off and replaced it with the old one. Vibration gone. ECS obviously sent me the wrong mount. The clutch pedal seems to engage down closer to the floorboard than before. Is there an adjustment for the pedal. I thought hydraulic clutches were self adjusting.
No pedal adjustment. I would suggest doing a bleed on your master cylinder first. When you did the clutch, was the fork and pivot ball replaced? those are 2 items which could contribute to that as well.
 
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