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147 Jtdm single mass flywheel issues

4K views 12 replies 6 participants last post by  AutolussoSouth 
#1 ·
Hi, I thought I'd share my experience of getting a single mass flywheel conversion on my 2007 147 jtdm 150. I bought the car with fsh knowing it had to have the timing belt and water pump done, which I did shortly after purchasing.

After about 5k the clutch started slipping. The clutch had always been hard but this got progressively worse until the pedal dropped one day which meant it was time for a new one. I had done quite a lot of research before and decided I was going to get a single mass flywheel conversion due to it supposedly being better if you were intending on chipping or remapping the car. It had about 80k on it at this point.

I got the single flywheel conversion, a new clutch and slave cylinder. Prior to any work the gearbox had always been very smooth, however it was clunky after. It started to get worse and I'd done just over 1k in it so I decided to go back to the garage that had done the work and rely on their expertise. It was suggested to remove the single mass and revert back to a dual. A couple of hundred pound later the single mass was removed and replaced. Initially this sorted the clunky gearbox issue but it soon came back and is getting progressively worse.

If anyone is looking to get a single mass flywheel conversion I would definitely recommend ensuring that the garage doing the work check any play in the crank shaft. I've spoken to a couple of Alfa specialists who said that is one of the few things they would've checked prior to carrying out the work, so it's unlucky the people who carried out my work didn't.

Over a grand down the pan and an engine which is inevitably going to go. If anyone has had a similar experience I'd be interested to hear.
 
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#3 ·
Thanks for the reply.

I've only be told that's there's play both horizontally and vertically in movement in the crankshaft. What I was told by the garage was that the dual mass reduced the effect of this play over the single mass which exemplified it. That could've been complete rubbish I was told and there may have been another cause.

Before the clutch went the gearbox was smooth, once the single mass was put on the gearbox became very clunky and difficult to get in gear. The dual mass that was put back on seemed to reduce this for a bit but became worse quite quickly.
 
#6 ·
I'd suspect either clutch drag due to hydraulic issues, air still in the system or master or slave cylinders. Or the usual gear linkage wear or misalignment.

Worn mains and thrust washers seem improbable causes, especially since the problem vanished after the DMF was installed. Some end-float is normal. IME knackered mains quickly get worse. They rumble loudly and sap power, and the low oil pressure (caused by loose clearances in the worn bearings) destroys big ends and everything else. I think you'd hear them if there was enough slop to detect but getting the oil pressure checked should rule them in or out.
 
#8 ·
Ok cheers, the issue disappeared initially when the dmf was put back on and then has comeback. I'm going to get it looked at by a transmission specialist. The engine itself runs very smoothly it's literally only the clunkiness of the gear changes into second and third, with a bit of play in fourth.

When the clutch went the slave cylinder did go so that may have caused drag on the clutch potentially.
 
#7 ·
It was in for a bit over a month and I'm starting to now think that there was an issue when installing the single mass that the garage knew about when they then put it back to the dual mass but kept quiet. It was done by a reputable garage but I know they were very busy at the time.
 
#10 · (Edited)
I'm assuming you bought the SMF and clutch together. They didn't put a JTD clutch in with the SMF did they. sounds more like the Gearbox/clutch than the crank. SMF might put a bit more shock through the gearbox and diff so might find them out if you're "enthusiastic " but more likely a leak or air in hydraulics. bleed it again first and cheapest option. Then check slave part number, really it should be a 3.2 V6 or the Std JTD one. They all look very similar but some from older models have a larger bore and this means they don't move the arm as far for the same pedal movement then check for over bending crushing of both the hard and flex clutch lines.
I'm sorry this has happened to you, I did mine 2 years ago and apart from a faulty Valeo clutch which failed due to manufacturer incompetence it's been great.
Finally if by the remotest of chances the garage that changed your clutch gave the YTS kid the job of refilling the box with oil just before his lunch break that would pretty much do for it. Putting thick oil in when they changed it back would disguise it for a while but not for long. did you check the oil level in the box at all?
 
#11 ·
Just thought I'd give an update after having the car looked at by an alfa specialist in Bristol this week. The car's been sat since late Feb as I was worried of doing anymore damage after reading a few things on here and hearing a few horror stories where the crank play gets much worse quite quickly.

The clutch, which was new, has a lot of scorch marks on it and the pressure on the slave cylinder is lower than it should be. When the SMF was fitted it's likely to have dragged the clutch. When I spoke to the garage, Autolusso, the second time after taking it back, they did say at that point they'd had to repressurise the slave, so this may explain it.
 
#12 ·
The clutch, which was new, has a lot of scorch marks on it and the pressure on the slave cylinder is lower than it should be. When the SMF was fitted it's likely to have dragged the clutch. When I spoke to the garage, Autolusso, the second time after taking it back, they did say at that point they'd had to repressurise the slave, so this may explain it.
None of this makes any sense. The Slave pressure (internal ?) is just a function of the resistance to movement at the actuator end and the slave piston diameter. The only reason it might be low is if the force required to move the clutch is low. This could be caused by the Slave having insufficient movement to fully operate the clutch perhaps, hence the dragging when clutch pedal fully down ?

"repressurise" - the Slave is "pressurised" by your foot applying a force to the Master cylinder piston via the clutch pedal. Once you release the clutch pedal there should be no pressure in the hydraulic circuit (any residual pressure vents back in to the brake reservoir) and the pressure in the Slave should be zero. Are you sure they didn't simply mean they bled air out of the Slave ?
 
#13 · (Edited)
Just thought I would clear up any confusion with regards to this situation and explain what happened and how.

As the OP has said we fitted a solid flywheel conversion and GTA clutch to his 147 1.9 16v. All went fine as per usual (probably changed well over 150 clutches on 1.9s now) and we also replaced the rear main oil seal at the same time as this was leaking. Again all very normal and something we often do.

Put it all back together, new slave cylinder, bled the system and road tested with no issues to report so handed the car back to the customer as per usual.

Few days or a week or so later the OP called saying there were some issues with selecting gears as he has said. I said bring the car back right away and we will get it checked over and make sure all is in order. We thoroughly looked over the car, re-bled the slave etc and it was still the same and hard to get into gear like the clutch was dragging. We double checked everything again and really couldn't see anything obvious at all.

So thinking cap on and bit of head scratching........ We measured the slave throw - all ok, checked linkages etc all ok. So more tools out and thought we would check for end float with a DTI gauge on the crank pulley end. We found over 1mm of end float. Way too much but certainly odd for these engines but either way it was there. We never would check for this on every car we do a clutch on and I really don't know a specialist who would unless there were concerns or related / suspected issues beforehand.

So had to make that dreaded call I sometimes have to make to customers which is never a nice thing to do. And just for the record I don't "spin stories" or lie to customers. I'm very honest and take pride in what we do and how I look after my customers be it a regular or a new one as it makes no difference. There are no secrets here and no stories that have been kept quiet. I have been running a workshop for a long time now and honesty is the only way! Mistakes get made; of course they do because we are human but when they do happen I own up and it gets put right no matter how big or small - end of.

I relayed all the above information to the OP and along with my theory that the solid flywheel is moving laterally with the crank (1mm is a lot!!!) therefore causing the aforementioned issue (this is an issue we have seen on quite a few GTAs before with the exact same symptoms). My suggestion was that the old slightly worn flywheel was taking up this play.

So we had a chat and I felt bad for my customer and the situation he was in with his car. I offered him a new JTD clutch fitted along with his old dual mass flywheel (which was in good order) for £200. We all know that doesn't even cover costs but I wanted to help as best I could as that is what I do and I am sure others will be able to vouch for that!! We also charged nothing for all of the investigation work and time we spent trying to get to the bottom of the issue.

So we fitted the old dual mass flywheel and new clutch. We noticed the rear main was also leaking again which confirmed the end float we had found. Once this was all fitted it seemed fine again and the car was handed back to the OP. The issue eventually returned and we are where we are now.

This is how it all happened and we made a judgement on the information we had in front of us. I'm also happy to take another look and show the OP how we came to the conclusion we did. I will give you a call on Tuesday to book seeing yourself the car again.

I hope that clears things up a bit? Any questions fire away!!

Loz
 
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