I hate flex discs

[Jean]

Few months back I had a shop install a new clutch, cylinders, tranny mounts, shifter parts and a guibo all at the same time. It lasted only about a month or so before it failed, here is what it looked it after removal -




Now, after about 2k-3k miles and a full season of autocross here is another guibo -










I don't understand why they keep failing, I thought maybe it's my super loose shifter somehow is touching it but that doesn't seem to be the case after close inspection , there seems to be enough clearance there.
What gives ?

[Ben Carufel]

I believe I've heard Trent say in the past that one of the things that tends to destroy flex disks quickly is when the harmonic balancer, that big weighted wheel installed on the front of your crankshaft, is out of balance.

[Jean]

I don't believe my car has one. Its an m20 item , yes ?

[JasonC]

If your harmonic balancer is out of balance then you should have a motor shake and your rod and main bearings will fail.

[benDASHDASH]

I don't believe my car has one. Its an m20 item , yes ?

I dont see one in the pics. Either way, yours should last longer. Something's gotta be hitting it.

[nando]

are you certain you put it in the right direction? they can be put in backwards, and they don't last very long that way.

[Hick]

Center bearing, leak, interference?

[Jean]

are you certain you put it in the right direction? they can be put in backwards, and they don't last very long that way.

Yep made sure to put it in correctly.

[Jean]

Center bearing, leak, interference?

center bearing was inspected for extra play when guibo #2 was installed, nothing unsual noticed. We pre-loaded the driveshaft forward a few mm's too.

[Mike325]

Do you feel any shakes in the car with a good flex disk. It could be your driveshaft or even the center bearing. This could cause the drive shaft to shake and rip up the flex disk.

Is your drive shaft in phase? Are the two U-joints in line with each other? I bet the shop that put your car together just pulled the front end of the drive shaft off and did not line it up perfectly.

[Hick]

Its all the raw torque from the M10

[Jean]

Do you feel any shakes in the car with a good flex disk. It could be your driveshaft or even the center bearing. This could cause the drive shaft to shake and rip up the flex disk.

Is your drive shaft in phase? Are the two U-joints in line with each other? I bet the shop that put your car together just pulled the front end of the drive shaft off and did not line it up perfectly.

After guibo #2 was installed there were no shaking until this weekend. I started noticing vibration and just now put the car on the jack stands and that's what I found out. So when the guibo was new there was no vibration, other than engine vibration in low rpm range (idle) thanks to ie engine and tranny mounts..

Shop didn't take the drive shaft apart when they installed guibo #1 along with all the clutch work, they moved the front part of it to a side and used a string or something else to hold it in place. That's what they told me at least.

Guibo #2 was installed by me and 2002 owner.

[Jean]

Its all the raw torque from the M10

lol

[e30lyf]

did you use OEM BMW? same happen to me. i bought from bavauto it last for 1500 miles. last month i bought from the dealer guibo & CSB. no issue so far.

[Erick]

Or maybe he bought the cheapest flex disc you can buy which sucks at life. I've had a flex disc last me 3 daily driving months. Changed it for a better one and got 2 years + massive track days.