Clutch/Transmission Woes (scratching & rattling)
03-04-2019, 09:06 AM
#1
Clutch/Transmission Woes (scratching & rattling)
Hello rotary hive mind, I have a fun issue i'm dealing with and would like anybody's help or suggestions because I'm out of ideas.
My 04 MT rx8 had a bad syncro, and needed replacing (was my father's car and to "save the clutch" he frequent shifted without it) so I figure if I'm going to replace the tranny I may as well do clutch, flywheel, pressure plate, the works. So here's what I ordered:
Flywheel Single-Mass for "puck style" clutch below
Clutch & Pressure Plate Stage 2 for track/drag use
Used Transmission With 45-65K on it
Normally this is an installation I would do myself, but I just took a long commute job and MN winters are not conducive with working on cars, so I take it to a dealership to have them install this. Before I get too much hate, I have had an exceptionally good experience and rapport with this Mazda dealer, and part of the reason why I took it there instead of a transmission shop is because IF i decide to sell this car, I can have verifiable paper trail with the same dealership the car was purchased from in 04. Their labor rate was reasonable so I have them install it...
And this is where the fun begins, the used transmission I purchased shifts like butter, syncros are all working and no weird or abnormal grinding or resistance, finally and RX8 i can drive! ... so I do, and notice pretty quick that there's a very loud scratching/rattling sound in 4th, 5th and 6th at lower rpm. As I'm well within the 30 day service guarantee from the dealership, I take it back to find out whats up. Turns out they flush the transmission fluid and theres way too much metal in the tranny, they diagnose it as a bad used tranny.
So what to do, I can send this transmission back, but ordering another used one will take like 1-2 weeks and I dont have that kind of time, so I get talked in to ordering a used transmission through the dealership, its $500 more, but comes with parts & labor warranty for the next year and unlimited miles, so if it turns out bad, I get a new one installed for free. I order that and have it installed. This one shifts like a clunky rock, grinds downshifting to 5th and has the exact same sound in 4th, 5th and 6th at low rpms, so back it goes.
The 3rd replacement arrives, and I leave the car for a few days for the tech to thoroughly diagnose whats going on: they replace the rubber boot between the tranny and shifter (it was torn and allowing noise to creep in, cool but that doesnt make the sound go away, it dampened it..) they also clamp some of the rusted heat shield to the cat (its on its way out and salt/rust hasnt been kind do it, replacing this summer) because that vibration might be making the sound. a good thing for sure, but im silently pessimistic as i can replicate the sound and it is coming from the clutch/flywheel area on a rattling exhaust. I also called Southbend and asked if this kit is compatible with a factory throwout/pilot bearing, and for good measure, had those installed.
So I'm on the 4th transmission this care has had now, this one shifts fine, syncros are great and it is quieter with the work they have done.... buttttt you guessed it, the sound in 4th 5th and 6th is still there, still just as pronounced from 2-3K rpm.
and at this point im driving around the scratching sound, if I shift above 4K, it'll drop down to 3K and I dont have the sound, but that shouldnt be a permanent fix, especially because when the sound is happening, if I press the clutch in an inch or two (not enough to drop rdm) the sound goes away.
To my thinking this screams that the clutch is out of adjustment, but Mazda is telling me it is properly adjusted, and my attempts at researching and reading the service manual have only suggested clutch pedal adjustment, but that only adjusts "bite" correct? I'm not sure what to do or try next short of going back to stock everything so any help would be greatly appreciated here, I wont be charged for labor if ask my Mazda dealer to help but I dont think they have any suggestions. Thank you in advance for any help!
My 04 MT rx8 had a bad syncro, and needed replacing (was my father's car and to "save the clutch" he frequent shifted without it) so I figure if I'm going to replace the tranny I may as well do clutch, flywheel, pressure plate, the works. So here's what I ordered:
Flywheel Single-Mass for "puck style" clutch below
Clutch & Pressure Plate Stage 2 for track/drag use
Used Transmission With 45-65K on it
Normally this is an installation I would do myself, but I just took a long commute job and MN winters are not conducive with working on cars, so I take it to a dealership to have them install this. Before I get too much hate, I have had an exceptionally good experience and rapport with this Mazda dealer, and part of the reason why I took it there instead of a transmission shop is because IF i decide to sell this car, I can have verifiable paper trail with the same dealership the car was purchased from in 04. Their labor rate was reasonable so I have them install it...
And this is where the fun begins, the used transmission I purchased shifts like butter, syncros are all working and no weird or abnormal grinding or resistance, finally and RX8 i can drive! ... so I do, and notice pretty quick that there's a very loud scratching/rattling sound in 4th, 5th and 6th at lower rpm. As I'm well within the 30 day service guarantee from the dealership, I take it back to find out whats up. Turns out they flush the transmission fluid and theres way too much metal in the tranny, they diagnose it as a bad used tranny.
So what to do, I can send this transmission back, but ordering another used one will take like 1-2 weeks and I dont have that kind of time, so I get talked in to ordering a used transmission through the dealership, its $500 more, but comes with parts & labor warranty for the next year and unlimited miles, so if it turns out bad, I get a new one installed for free. I order that and have it installed. This one shifts like a clunky rock, grinds downshifting to 5th and has the exact same sound in 4th, 5th and 6th at low rpms, so back it goes.
The 3rd replacement arrives, and I leave the car for a few days for the tech to thoroughly diagnose whats going on: they replace the rubber boot between the tranny and shifter (it was torn and allowing noise to creep in, cool but that doesnt make the sound go away, it dampened it..) they also clamp some of the rusted heat shield to the cat (its on its way out and salt/rust hasnt been kind do it, replacing this summer) because that vibration might be making the sound. a good thing for sure, but im silently pessimistic as i can replicate the sound and it is coming from the clutch/flywheel area on a rattling exhaust. I also called Southbend and asked if this kit is compatible with a factory throwout/pilot bearing, and for good measure, had those installed.
So I'm on the 4th transmission this care has had now, this one shifts fine, syncros are great and it is quieter with the work they have done.... buttttt you guessed it, the sound in 4th 5th and 6th is still there, still just as pronounced from 2-3K rpm.
To my thinking this screams that the clutch is out of adjustment, but Mazda is telling me it is properly adjusted, and my attempts at researching and reading the service manual have only suggested clutch pedal adjustment, but that only adjusts "bite" correct? I'm not sure what to do or try next short of going back to stock everything so any help would be greatly appreciated here, I wont be charged for labor if ask my Mazda dealer to help but I dont think they have any suggestions. Thank you in advance for any help!
03-15-2019, 11:06 AM
#4
I dont think so, sound is definitely not coming from the back, it sounds like the front of the transmission right in the clutch area. Diff is also in good shape, I checked the clutch disks a few weeks back and fluid got flushed recently.
03-15-2019, 11:19 AM
#5
Smoking turbo yay
If it's the clutch, I would expect this to happen in all gears.
Might be difficult if the dealer is doing the work, but I would just throw an S2 transmission on there. S1 Aisin units are known to be fragile. You will need to modify the electric connectors(for reverse switch, etc.), but otherwise it bolts right up.
Might be difficult if the dealer is doing the work, but I would just throw an S2 transmission on there. S1 Aisin units are known to be fragile. You will need to modify the electric connectors(for reverse switch, etc.), but otherwise it bolts right up.
05-25-2020, 09:42 AM
#6
An update on this for anyone that is curious: this was actually a faulty pressure plate... the springs were loose and would vibrate at specific RPMs. Replaced it resolved the issue.
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