Flex Disc ?

[Couverman98682]

Does anyone know about the flex disc and how long they should last. I have been experiencing some shudder when my car is very warm and stuck in traffic. It feels like the whole driveline is hopping around and the dif is chatering. I don't have this problem unless I'm stuck in traffic and have been idling for a long time.

[sKunkman]

I actually found the same problem yesterday when stuck in traffic.

It wasnt chattering so much as difficulty engaging the clutch (felt mushy). Any thoughts on that? Not trying to hijack of course =P

[Couverman98682]

need to get under the car and take a look. I was hoping someone had some experience with this issue

[angel318ti]

kinda sounds like throw-out bearing

[1996 328ti]

I don't think a flex disk is going to cause a problem while sitting in traffic. I mean, the driveshaft is not turning. I know I need a throwout bearing. I had a hard time in the winter getting into 1st and I'm starting to grind gears.

[juanp22]

I'm changing the flex disc on mine right now. Get under your car with a flashlight touch it with your fingers to see if it is damaged, since you will only be able to see one side. I don’t think your problem is the flex disc, like the previous post says “in traffic the driveshaft is not turning” it is not getting hot or anything. Im changing mine because when I change gears, and especially when Im in driving in first gear and I let the throttle go, and accelerate again the car starts to like jump (makes it feel like an old car or like I don’t know how to drive stick shift) I’m hoping the flex disc will smooth the transition of traction from the transmition to the driveshaft.

I don’t know if your car is manual or automatic; but, I think you have a clutch problem. When the clutch is worn, and you’re driving in traffic using your clutch a lot, it gets hot and the car starts to shudder.

If it makes a lot of noise when it shudders, check the transmition mounts they very are close to the flex disc and also check the engine ones the might be worn.

[Den]

When the flex disc (AKA Guibo) went bad in my 535, it caused a 'clunk' in the driveline when shifting.

You can tell if it's going bad by looking for cracks in the rubber around the metal bolt sleeves.

[mickd]

The problem seems to me like clutch "judder", common problem on the clutches in our ti's. It will usually only happen in hot temperatures and continuous starting and stopping. It is a problem the factory knew about but did not cover under warranty. The "judder" will go away once the clutch cools down.

[Couverman98682]

my mechanic said its probably the bearing and rubber mounting that is in the middle section of the drive line. He will be replacing those parts and while he is in there do the flex disc and have the drive line balanced.

[mickd]

I think you are wasting your money, there were MANY posts on this in the old 318ti mailing list archive. My car does it on 80 degree (or more) days when stopping and starting on the freeway in rush hour traffic. I've just lived with it because I seldom am in that situation, and my car has 129K miles. If you release the clutch fast without alot of throttle the "juddering" isn't as bad. Here are 2 of many posts about the problem: http://staff.connect.com.au/lheather.../msg00244.html
http://staff.connect.com.au/lheather.../msg00039.html

[Couverman98682]

So is this shuddering that happens on hot days while in stop and go traffic caused by a warm clutch or is it related to the carrier bearng and the rubber part around it becoming deteriorated. I have stop and go traffic for at least 45 minutes for my drive home from work so this is seriously irritating to say the least. How do I get the car to run smooth even on hot days. Money really isn't an issue.

[mickd]

It is the clutch itself. I would say it is the clutch disc that has uneven grip around it's perimeter when hot, probably due to the friction material used since BMW went to non-asbestos. Here are 2 more links on the problem:
http://digest.net/bmw/archive/v5/msg01583.html
http://66.102.7.104/search?q=cache:2...&hl=en&start=5

[Den]

Originally Posted by just_a_dude_in_the_couve

my mechanic said its probably the bearing and rubber mounting that is in the middle section of the drive line. He will be replacing those parts and while he is in there do the flex disc and have the drive line balanced.

As I said, a worn flex disc causes a clunk during shifting. Once the shift is completed and driveshaft speed matches engine speed, the slop in the worn flex disc is taken up,"clunk," and the flex disc does not shudder or vibrate after that, IME.

Balancing the driveshaft sounds like a waste of $. . .not likely to be an issue at low speed in stop+go traffic.

If you are going to spend $ on the driveshaft, you should just go ahead an get a rebuilt one because the U-joints will eventually wear out and are not serviceable(can't be greased or replaced), so you will need to replace the driveshaft at some point anyhow if you keep the car for a long time.

Rebuilt driveshafts usually include a new center support bearing(CSB). A worn CSB can be a source of vibration in the driveline, but the correlation with ambient temperature sounds more like a clutch thing to me. Don't be surprised if you spend $500 on your driveshaft and your problem persists.

If you are determined to do the driveshaft now,
here are some driveshaft places:

Mesa Performance Parts(CA)
http://www.mesaperformance.com/web_s...=2957695.17317

Driveline Service of Portland(OR): 800-227-8608

D.L.S of Atlanta (Georgia): 770-242-9366

[Couverman98682]

It's getting HOT out again and I still Havn't replaced the clutch or anything on the driveline. My judder problem is back and I need to get it fixed. Is there an upgraded clutch kit available for my car or should I stick with a fresh stock piece. Replacing the flywheel is not an option for me at this time.