[ab987]

Well, that didn't take long.
I was doing some logs on e50 after installing the walbro 535 yesterday (a few 1-2-3s), and it seems like I've damaged the input shaft bearing by shifting too hard, it now faintly whines when the clutch isn't pressed, engine speed and load dependent. Has anybody else done this? These transmissions were supposedly bullet proof, and 500wtq or so seems a bit low to damage these transmissions. It was perfectly happy with 93.

Fluid was done 3 months ago
550i clutch done 3 months ago
Clutch delay valve still installed

It looks like these guys sell the bearings here so I'm gonna try to get mine rebuilt, but I don't particularly want this happening again.

[Saif2018]

Originally Posted by ab987

Well, that didn't take long.
I was doing some logs on e50 after installing the walbro 535 yesterday (a few 1-2-3s), and it seems like I've damaged the input shaft bearing by shifting too hard, it now faintly whines when the clutch isn't pressed, engine speed and load dependent. Has anybody else done this? These transmissions were supposedly bullet proof, and 500wtq or so seems a bit low to damage these transmissions. It was perfectly happy with 93.

Fluid was done 3 months ago
550i clutch done 3 months ago
Clutch delay valve still installed

It looks like these guys sell the bearings here so I'm gonna try to get mine rebuilt, but I don't particularly want this happening again.

500lb/ft?

What's the transmission rated at and are there guys running more than 500lb/ft torque at flywheel reliably ?

Not sure what you mean by Bullet proof, every transmission can be damaged.

[ab987]

Originally Posted by Saif2018

500lb/ft?

What's the transmission rated at and are there guys running more than 500lb/ft torque at flywheel reliably ?

Not sure what you mean by Bullet proof, every transmission can be damaged.

Sure, I mean relative to other transmissions ours are *very* stout (I'm sure you've heard of some turbo LS/Supra cars running our boxes), so it surprised me when people run single turbo cars in the 650-700lbft range and beat the shit out of their transmissions much more than I do, my transmission is the one that shits the bed. Transmission is rated for 442 lb ft (600Nm) which is just under what I am making on my stockers, and by the time I am shifting I am making well under that number.

[Saif2018]

Originally Posted by ab987

Sure, I mean relative to other transmissions ours are *very* stout (I'm sure you've heard of some turbo LS/Supra cars running our boxes), so it surprised me when people run single turbo cars in the 650-700lbft range and beat the shit out of their transmissions much more than I do, my transmission is the one that shits the bed. Transmission is rated for 442 lb ft (600Nm) which is just under what I am making on my stockers, and by the time I am shifting I am making well under that number.

Could be your shifting that caused the damage?

I found the ZF6 to be more reliable than the manual BMW transmissions from experience, but maybe that's just bone stock transmissions I've been driving in older cars. With uprated clutch and flywheel in good order they cam handle huge torque

[ab987]

Originally Posted by Saif2018

Could be your shifting that caused the damage?

I found the ZF6 to be more reliable than the manual BMW transmissions from experience, but maybe that's just bone stock transmissions I've been driving in older cars. With uprated clutch and flywheel in good order they cam handle huge torque

I'm fairly certain my shifting played a role, because I didn't quite flat foot shift but still was in the 11psi range mid-shift at 13 deg of timing. Changed the fluid tonight and it was quite dark but no obvious metal. Same sound though. I found a shop that could source the bearings so this winter I'll probably have them change them out. And yeah, I know these can hold lots of torque, that's why I was surprised when a mild car (in comparison to some of the big twin cars) was making enough to damage it.

[Saif2018]

Originally Posted by ab987

I'm fairly certain my shifting played a role, because I didn't quite flat foot shift but still was in the 11psi range mid-shift at 13 deg of timing. Changed the fluid tonight and it was quite dark but no obvious metal. Same sound though. I found a shop that could source the bearings so this winter I'll probably have them change them out. And yeah, I know these can hold lots of torque, that's why I was surprised when a mild car (in comparison to some of the big twin cars) was making enough to damage it.

Flat foot shifting needs to be mapped in as far as I'm aware, you had ot mapped in by a tuner?

It doesn't matter how strong the gearbox is, if you shift badly, it's possible to damage any manual transmission.

[ab987]

Originally Posted by Saif2018

Flat foot shifting needs to be mapped in as far as I'm aware, you had ot mapped in by a tuner?

It doesn't matter how strong the gearbox is, if you shift badly, it's possible to damage any manual transmission.

That's what I'm saying, it wasn't at all flat foot. I treat my gearbox much nicer than most people I know, I'm surprised they don't have dents in their consoles from how hard they punch into gear. When I'm shifting quickly like this, it's not with much force on the shifter, only it's quick and clutch actuation is shortly after on a factory BMW clutch designed for the gearbox. Meanwhile people with twin disc clutches and all that are beating the living crap out of theirs, absolutely banging gears...

[Saif2018]

Originally Posted by ab987

That's what I'm saying, it wasn't at all flat foot. I treat my gearbox much nicer than most people I know, I'm surprised they don't have dents in their consoles from how hard they punch into gear. When I'm shifting quickly like this, it's not with much force on the shifter, only it's quick and clutch actuation is shortly after on a factory BMW clutch designed for the gearbox. Meanwhile people with twin disc clutches and all that are beating the living crap out of theirs, absolutely banging gears...

Twin disc clutches can hold serious torque so not surprised.

Have a read through this,

https://www.e90post.com/forums/showthread.php?t=1750081

Guys on there saying 550 clutch isn't good for anything more than 500wtq

If that's the case, you may also be pushing the clutch to its limits

[ab987]

Originally Posted by Saif2018

Twin disc clutches can hold serious torque so not surprised.

Have a read through this,

https://www.e90post.com/forums/showthread.php?t=1750081

Guys on there saying 550 clutch isn't good for anything more than 500wtq

If that's the case, you may also be pushing the clutch to its limits

That's okay with me, I'm 5000 miles in with absolutely no slipping. I'm surprised that twin disc clutch guys can get away with flat foot shifting without WOT boxes and whatnot and the transmission just doesn't care... but my 550i clutch supposedly grabbed hard enough to damage the input shaft bearing

[Saif2018]

Originally Posted by ab987

That's okay with me, I'm 5000 miles in with absolutely no slipping. I'm surprised that twin disc clutch guys can get away with flat foot shifting without WOT boxes and whatnot and the transmission just doesn't care... but my 550i clutch supposedly grabbed hard enough to damage the input shaft bearing

Have you inspected the gearbox to confirm its the input shaft bearing?

[ab987]

Originally Posted by Saif2018

Have you inspected the gearbox to confirm its the input shaft bearing?

I don't have the tools (ZF has a monopoly on parts, tools, and manuals), but there really isn't anything else I can think of. It is directly tied to engine rpm and only happens under load (shaft deflection is causing it I think) in any gear. I can't think of anything else it would be besides the shaft gears whining, but that doesn't explain how dirty my almost-brand-new fluid was.

[kevlarblue]

Can you finish this story for me please?

I have an M5 with a GS6-53BZ transmission making a similar noise and I want to investigate the input shaft bearing. Did you find a way to replace it? Did it work to eliminate the noise? Cost?