5 speed vibration

#1 02-13-2005, 09:30 PM

Hello everyone,

I recently put an impreza 5 speed in my 92 svx, and I've got a weird vibration now. It 's not due to the driveline at all because it does it while it's idling, and the vibration progresses according to the engine RPM. I think it might be due to the clutch unbalancing the motor, since the clutch pack is a lot heavier than the original flex plate. Has anyone else experienced this? Any ideas/ input would be greatly appreciated.

Thanks

Daniel

mbtoloczko · #2 02-13-2005, 10:18 PM

I think there is not problem with the weight of the flywheel/clutch assembly. There are several people who are running standard WRX flywheels which are as heavy or heavier than your Legacy flywheel. Might be that your flywheel and/or clutch is out of balance.

huck369 · #3 02-14-2005, 05:37 AM

The manual flywheel/cluth asembly is LIGHTER than a flex plate and Torque converter filled with tranny fluid.....
It's not the weight.

It could be a bad flywheel, or a baddly balanced clutch/pressure plate.

#4 02-14-2005, 08:59 AM

That is most likely the problem then. I read a post about a vibration being caused by the angle of the motor being slightly wrong after doing a 5 speed swap. Has anyone else run into that problem?

mbtoloczko · #5 02-14-2005, 09:03 AM

Yeah, I posted that. A significant change in the tiltback of the motor would only cause driveline vibration through bad u-joint angles. No effect like what you are seeing with your car.

#6 02-14-2005, 04:19 PM

Thats what I thought, but I thought I'd throw it out there and see what the experts thought

. Thanks

Earthworm · #7 02-15-2005, 12:56 PM

It's not something simple like your exhaust banging against the tranny crossmember?

#8 02-15-2005, 10:28 PM

Definately not. It really feels like something out of balance with the motor.

mbtoloczko · #9 02-16-2005, 12:09 AM

If the flywheel and/or clutch are out of balance, you should feel it very strongly when you rev up the motor. I guess you're going to have to drop the tranny?

#10 02-16-2005, 08:43 AM

Yeah, But I'm pretty used to doing Subaru trannies by now. I've got an impreza clutch in it now, but I was thinking about putting a legacy clutch back into it if it's a bigger clutch. Does anyone know if it is bigger, and if the sline is the same for the input shaft?

huck369 · #11 02-16-2005, 11:10 AM

The Impreza and Legacy use the same size clutch, and same tranny, and flywheel, unless it's a WRX

Subafreak · #12 02-16-2005, 08:31 PM

YES! I was having the same problem. Do you have the STI mount in the car? I noticed the problem most after I instaled the STI mount. It had a vibration that would get really noticable around 3,500 to 4,000 RPMs just reving the engine. I even took out the tranny to check the flywheel and clutch plate tourqe to make sure that wasn't it. The problem seemed to get better after after I realized I was over filling the oil system put it was still there a bit. I was using the 92-94 turbo Legacy tranny and flywheel setup. I'm not sure if it has gone away with 6 speed swap yet or not.

#13 02-16-2005, 09:09 PM

No, I've got a stock '96 impreza tranny mount set up. The problem got better after you realized you were over filling it with motor oil? When you retorqued your clutch and flywheel, did you have them checked to see if they were balanced?

Subafreak · #14 02-17-2005, 06:13 PM

Well I didn't feel it befor I put the STI tranny mount in. I only thought the oil thing made a difference. The clutch and flywheel had no reson to be out of balance.

huck369 · #15 02-17-2005, 07:18 PM

All engines have certain harmonics that will be apparent at different RPM levels, the flat 6 is about as close to perfect as they come…but still will produce vibrations, the factory liquid filled mounts really do a good job of hiding them, but with the STi mounts, or even the factory Impreza tranny mount, there are more vibrations transmitted through them since they are denser material,… So are you sure it’s not just normal engine vibrations?