Manual transmission question...
Thread Starter
Instructor
Joined: Aug 2008
Posts: 235
Likes: 0
From: Orlando Florida
Manual transmission question...
Hi all, having a problem with my new 5 spd manual trans. conversion. Everything shifts fine...new hd clutch, pp, throw out bearing also installed. The problem occurs at highway speeds and transmission tunnel area begins to vibrate, noticeably but driveable. I feel the exact vibration when I touch the shifter handle...installed new hd driveshaft that was balanced with all new ujoints. Can there be a bellhousing lineup problem?...anyone experience this also...? Any input would be appreciated...used stock bellhousing, not scatterplate...???
Thx- DDBS
Thx- DDBS
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Suspect possible driveshaft alignment issues. Are the crank CL and pinion CL pretty close to parallel (not concentric) and at 2-3* with the shaft such as in the exaggerated illustration below?
If this isn't it, did you check the bell to be concentric and parallel with the crank?
If this isn't it, did you check the bell to be concentric and parallel with the crank?
Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
Is vibration noticed at a specific rpm range or a specific road speed...
This will help to isolate whether problem is motor/clutch or trans and driveline or even tyres.
If it occurs consistently at a specific rpm, in each gear, then look for possible contact of bell housing or trans to the body... that is, inadequate clearance between body and engine/trans. Don't forget that under hard accelleration, there is torque twist which will move the motor around a bit due to the rubberised engine mounts.
If that's not the issue, then possibly a clutch problem or out of balance flywheel/clutch ???. do you have an internally (neutral) balance rotating assembly or an external balanced type?
Also possible cause might be pilot bearing or flywheel eccentricity.... Did you check runout?
........................................ .......................
If the vibration occurs at a specific speed range, then the problem is more likely to be related to driveline after the trans output.
Tailshaft balance is first item to consider,
Also need to check your tranmission alignment and universal joint angles. There's plenty of info on this subject on the forum.
Chasing vibrations can be a real PITA to solve.
I have had an annoying vibration since installing my Tremec TKO600.. comes in at 45 mph and disappears at 50mph.
Still haven't found the cause.
This will help to isolate whether problem is motor/clutch or trans and driveline or even tyres.
If it occurs consistently at a specific rpm, in each gear, then look for possible contact of bell housing or trans to the body... that is, inadequate clearance between body and engine/trans. Don't forget that under hard accelleration, there is torque twist which will move the motor around a bit due to the rubberised engine mounts.
If that's not the issue, then possibly a clutch problem or out of balance flywheel/clutch ???. do you have an internally (neutral) balance rotating assembly or an external balanced type?
Also possible cause might be pilot bearing or flywheel eccentricity.... Did you check runout?
........................................ .......................
If the vibration occurs at a specific speed range, then the problem is more likely to be related to driveline after the trans output.
Tailshaft balance is first item to consider,
Also need to check your tranmission alignment and universal joint angles. There's plenty of info on this subject on the forum.
Chasing vibrations can be a real PITA to solve.
I have had an annoying vibration since installing my Tremec TKO600.. comes in at 45 mph and disappears at 50mph.
Still haven't found the cause.
Thread Starter
Instructor
Joined: Aug 2008
Posts: 235
Likes: 0
From: Orlando Florida
Suspect possible driveshaft alignment issues. Are the crank CL and pinion CL pretty close to parallel (not concentric) and at 2-3* with the shaft such as in the exaggerated illustration below?
If this isn't it, did you check the bell to be concentric and parallel with the crank?
If this isn't it, did you check the bell to be concentric and parallel with the crank?
Thread Starter
Instructor
Joined: Aug 2008
Posts: 235
Likes: 0
From: Orlando Florida
Is vibration noticed at a specific rpm range or a specific road speed...
This will help to isolate whether problem is motor/clutch or trans and driveline or even tyres.
If it occurs consistently at a specific rpm, in each gear, then look for possible contact of bell housing or trans to the body... that is, inadequate clearance between body and engine/trans. Don't forget that under hard accelleration, there is torque twist which will move the motor around a bit due to the rubberised engine mounts.
If that's not the issue, then possibly a clutch problem or out of balance flywheel/clutch ???. do you have an internally (neutral) balance rotating assembly or an external balanced type?
Also possible cause might be pilot bearing or flywheel eccentricity.... Did you check runout?
........................................ .......................
If the vibration occurs at a specific speed range, then the problem is more likely to be related to driveline after the trans output.
Tailshaft balance is first item to consider,
Also need to check your tranmission alignment and universal joint angles. There's plenty of info on this subject on the forum.
Chasing vibrations can be a real PITA to solve.
I have had an annoying vibration since installing my Tremec TKO600.. comes in at 45 mph and disappears at 50mph.
Still haven't found the cause.
This will help to isolate whether problem is motor/clutch or trans and driveline or even tyres.
If it occurs consistently at a specific rpm, in each gear, then look for possible contact of bell housing or trans to the body... that is, inadequate clearance between body and engine/trans. Don't forget that under hard accelleration, there is torque twist which will move the motor around a bit due to the rubberised engine mounts.
If that's not the issue, then possibly a clutch problem or out of balance flywheel/clutch ???. do you have an internally (neutral) balance rotating assembly or an external balanced type?
Also possible cause might be pilot bearing or flywheel eccentricity.... Did you check runout?
........................................ .......................
If the vibration occurs at a specific speed range, then the problem is more likely to be related to driveline after the trans output.
Tailshaft balance is first item to consider,
Also need to check your tranmission alignment and universal joint angles. There's plenty of info on this subject on the forum.
Chasing vibrations can be a real PITA to solve.
I have had an annoying vibration since installing my Tremec TKO600.. comes in at 45 mph and disappears at 50mph.
Still haven't found the cause.
