Clutch Balance

[pchflyer]

I just had the clutch, pressure plate and center dougnut replaced on my Flaminia Convertibile. It cured the original ill of clutch slip, but added another: drivetrain vibration around 2500 rpm engine speed. The good: the vibration decreases to none as the revs increase. My mechanic (knowledgeable) said his balance "guy" says this particular pressure plate/clutch combo can't be balanced-something about the design of the forks? Assuming the doughnut is not the source (reasonable?), me (not knowledgeable) can't believe that this cant be balanced. Pic is of the old parts- replaced with similar.

[Jay]

You can balance a Flaminia clutch, Vibration Free did my, they balance the whole assembly of the 3 main parts in the bell/clutch housing, you just need to bolt it on the gearbox and turn the shaft, dis and engage it a couple of times to seat it, then give it to him. It a strange way to balance a clutch, but it works a treat.

However it's very important to keep all the prop-shaft components exactly the same, including the bolts, if not you my have to balance the whole prop-shaft insitu. Also if you got the gearbox out i would recommend replacing the the seal between gearbox and clutch housing as this one reason why the clutch can start slipping. As a small amount of oil seeps past the seal and these clutches can get very hot with a lot of stop start traffic so the oil turns to vapour and gets on the surfaces.
     

[pchflyer]

Thanks Julian,
I think I "got it"- the new parts need to seat before balancing. I'm not sure why my mechanic (generally very knowledgeable) didn't know a specialist that could do it-but I am in the States and some expertise may be lacking. It obviously would have been easier to do this last week when the car was still on the lift. I will investigate further... Good advice about the seal. To my eye, the clutch was worn but not completely, and there were burn marks? on the pressure plate and no *obvious* oil, but I didn't look that closely. (I didn't do the work!)

[FERGTS246]

Hi Jay, Was your problem vibrations at 2500rpm. Did Vibration-Free sort it out with the transaxle in the car and hooked up to the propshaft?
Thanks in advance. Chris

[FERGTS246]

Hi Pchflayer. Did you get your vibration sorted? If yes, what was causing the vibration?
Thanks Chris

[Jay]

Hi Chris
How are you? If I remember the vibrations came with the car and started around 50 to 60mph in forth so yes about 2500 and above. When I replaced the clutch plate I had it balanced by vibration free, I gave him the bell housing containing all the clutch parts, so off the car and no shafts. As mentioned above you have to ‘seat’ (dis and re-engage) the clutch a few times to get it nice and central. As you know first hand it worked a treat as demo by the run up the A3.

Thanks Jay

[FERGTS246]

Jay, Sorry I didn't realise it was you(-:.

Yes it was very nice on the A3, I'm well and I hope you and your family are too.

I'm not sure when the latest clutch was put in my Flaminia, it may have been by the restorers in Italy, so about 24 months ago so I imagine its well bedded in by now.
It has had the vibrations between about 2k to 2.5k rpm ever since I've had - they seem to come from the transaxle area.
VibrationFree said that they can do a 'diagonsis' session for about £85.00 when, apparently, they can tell what is causing the vibs.
Do you anything about this 'diagnosis' sesssion?
Best
Chris

[Dave Gee]

When I built my Sport, 25 years ago, on the first test run I experienced bad vibration. I solved it by taking the prop shaft off and sending it to a specialist prop shaft manufacturer who will also balance them. At the same time I had it modified by putting a 50mm sliding joint in one end of the shaft so that should I ever need to replace the clutch, I would not need to first remove the prop shaft.
Earlier this year, after hearing a horrible noise from the clutch bell housing, I slid the prop out of the way and took the bell housing off, to find that the bearings in the front of the housing had gone. After replacing the bearings I again experienced vibration. On advice from Vibration Free, I removed the bell housing and complete clutch assembly from the car. Then, I removed the friction plate from the assembly, as requested. Vibration Free rebalanced the assembly at a cost of £85. On refitting the complete assembly, there was no discernible vibration. £85 well spent. Hope this helps.

[dannels]

I did the same as Dave - sent the whole clutch basket to vibration free - they balanced it and no vibration. No investigation...

Cheers
Dave

[Jay]

Hi Chris,
Dave, Dave and I all sent the complete clutch assembly to Vibration Free. However knowing your car had a recent complete rebuild it could also be the prop-shaft. I was told when dismantling the prop-assembly make sure it goes back together with the shafts and couplings lined up the same way with all the bolts, washers and nuts in the exactly same place. If these are mixed up then prop assembly can become out of balance.  All you know is that the last restorers didn’t do this, so it needs rebalancing throughout. It may be worth taking it down to VF for them to have a look.

Thanks Jay

[FERGTS246]

Hi All,
Many thanks for the advice.
Chris