Clunk when transitioning to engine driving and engine braking (on/off throttle)

[Stuwey]

Mine is the 'fast road' insert. Can't see why you'd go any stiffer for something you drive all the time.

[kaanage]

OK, finally got another torque arm with a ployureathane bush (APR fast road) and had it installed. Again, the clunking has been reduced but it's still there .

While the car was up on the hoist we rechecked the driveline and the only thing noticable is a slight amount of backlash in the differential (nothing at all at the CV joints). My mechanic thought the amount of backlash was pretty normal but also that the Polo (VAG cars) may be tighter in this area than the cars he normally deals with.

So the cure would seem to be a new diff

[GoLfMan]

So the cure would seem to be a new diff

who cares, drive it until it pops, then chuck an LSD in there.

[kaanage]

If I can't get it warrantied , then that is EXACTLY what is going to happen
My only concern is that if it grenades badly enough, it may take out the rest of the gearbox internals and cases with it so I will be monitoring the noise level VERY carefully.

[Tim]

Have you guys ruled out the dual mass flywheel yet? Ive heard of quite a few being replaced on the diesel golfs.
There are a couple of videos on youtube showing the amount of play that exists in a failed one.

[kaanage]

The car was in neutral when we had it up on the hoist and checked the backlash - I may have to try it again, in gear

[kaanage]

I had the clunk diagnosed by Burwin VW and they said it was due to the passenger front hub bearing failing because a stretch nut there had been loosened and retightend when my cup kit was fitted and the nuts need to be replaced. I bought a bearing kit from them plus nuts for both sides to get my mechanic to fit them. Funnily enough, the clunk was reduced after the Burwin visit so I wonder if one of their mechanics tightened the hub nut when inspecting it.

My mechanic couldn't see any reason why the hub nut would have been loosened when the cup kit was installed (by someone else) but replaced the bearing on my instruction and now the clunk is gone. The original bearing seems OK (smooth and quiet) so I can use it as a spare when I kill one.

Even though Burwin wouldn't cover the bearing under warranty, I'm happy with them as their diagnosis seems to have been at least reasonably accurate (although I did have other work done to the front that could have removed the cause too) and I was only charged a small inspection fee. Unlike the the a$$holes that misdiagnosed my car who spun me the line about it being a CV joint and charged me heaps for the bs diagnosis . I'm going to confront them about this and give them a chance to respond before naming the morons.

[csimpson]

Very interesting, thanks for that. Any idea of the price for the bearings? I may replace mine.

Also swtiching to a single mass flywheel with the new clutch, so that may help...

[kaanage]

Here is what happened when I discussed the faulty diagnosis with the original dealer (Barloworld Moorabbin ).

http://www.vwwatercooled.org.au/forums/f40/misdiagnosis-dealer-what-next-64680-4.html#post781337

Needless to say, I won't be going back there and don't recommend anyone else should, either

[csimpson]

Switching to my new clutch I have no clunking now.

HOWEVER, I think the ECS 14lbs flywheel or thrust bearing is ****ed (in the new kit), it's making a terrible noise at idle and below 2500RPM. I'm taking it back to Camden GTI tomorrow for them to diagnose and fix: if it's either the flywheel or the bearing, I'm going to be kicking up a huge fuss at ECS.

There's always something wrong...

[VWindahouse]

It's unfortunately a standard side effect with the light weight flywheel mate. I have the same one from ECS. I do however remember Jimmy saying a part fix is using a new OEM bearing not the ECS one. He did this with mine and I only hear the chatter noise at idle when I have the aircon pumping. But even then a little rev will usually help dissipate it.

Hope it helps!

[csimpson]

Surely something up with the flywheel - it sounds worse than a diesel! I've posted a video in the What Did You Do Today thread, can you share your experience?

[sambb]

sorry - I'd started a new thread on this same problem as what Kaanage had experienced until I dug this one out of the achive.

I too have this knocking when the engine is ever so slightly loaded/unloaded with the throttle at low rpm.

To test whether the front wheel bearing preload stretch nut has loosened (it may have since both inner driveshaft boots were done on the car the year before I bought it) I plan on tightening it slightly and then seeing if the knocking goes away. If it does i'll order new stretch nuts but I'm unsure how to do the preloading. I'm ok with the castellated nut/cotter pin method but that requires you to take up the tension and then back off from there to a running postion. But I'm unsure if this is the way to go with a stretch nut which by definition shouldn't be backed off from its final position as this voids its ability to hold a certain torque setting doesn't it? Or are they fitted with a torque wrench setting?

So how do I go about finding the correct pre load considering also that the original bearings ( 6yo 28k km) will likely remain in the car?

thanks for any help
sam

[kaanage]

Actually, the hub replacement didn't quite eliminate the noise - it did reduce it to just a 4th and 5th gear issue at low rpm (see http://www.vwwatercooled.com/forums/...tml#post782189 for more details). There may have been a slight amount of stretch on the hub nuts but it could also have been the bolts holding on the control arms (I had the SEAT Cupra rear bushes installed at the same time).

The noise finally went away after I installed some subframe sleeves that Eddy had made up a while ago (I bought the last set).

Sorry for not updating this thread properly back in the day but it died with the tangent discussion about lightweight clutch replacements and I didn't think anyone was still interested in the original issue. I will see if I can get the torque for the hub nuts for you.

edit
BTW sambb, your inbox is full so I couldn't reply to your PM on this so I'd check the bolts for the front control arms and subframe as they seem more likely culprits to me, now.

[sambb]

righto, thanks for getting back to me on the forum. It really is a chorus of noises in front of me now. Even though everything looks to be ok its going to cop a complete re bush after I check the front hub nuts. If that doesn't do it i'll order a new set of subframe stretch bolts.
thanks
sam