Extra vibrations when moving
08-02-15, 11:43 AM
#1
Full Member
Thread Starter
Extra vibrations when moving
Recently my car developed a slight metallic sound when I would start to move as if two pieces were hitting together. I was almost certain it was u joints so I left it for a time I could get to it. Yesterday it got worse. The sound became constant whenever it was moving. I checked the trans fluid and it was low so I put almost a quart in it and lifted the rear end and let the rear wheels turn to see if it would go away or lessen. It stuck around for a while and just as I went to video it quit. Now the clicking sound is quieter than before but it vibrates the faster I go, clutch in or out. When on the gas it seems to tighten up and vibrate less but when I let off it shakes everything.
08-02-15, 12:05 PM
#2
Since the manual trans only holds 2.1 quarts, having to add one quart means it was really low.
What type of fluid did you add?
You should probably still check the u-joints and trans mount isolator. The trans itself won't make it shake like your describing but the trans mount could. I'm betting u-joints though.
Are the wheels still spinning when you observe the vibration with the clutch in?
What type of fluid did you add?
You should probably still check the u-joints and trans mount isolator. The trans itself won't make it shake like your describing but the trans mount could. I'm betting u-joints though.
Are the wheels still spinning when you observe the vibration with the clutch in?
08-02-15, 12:11 PM
#3
Full Member
Thread Starter
Since the manual trans only holds 2.1 quarts, having to add one quart means it was really low.
What type of fluid did you add?
You should probably still check the u-joints and trans mount isolator. The trans itself won't make it shake like your describing but the trans mount could. I'm betting u-joints though.
Are the wheels still spinning when you observe the vibration with the clutch in?
What type of fluid did you add?
You should probably still check the u-joints and trans mount isolator. The trans itself won't make it shake like your describing but the trans mount could. I'm betting u-joints though.
Are the wheels still spinning when you observe the vibration with the clutch in?
Last edited by Al Capwned; 08-02-15 at 12:23 PM.
08-03-15, 01:50 AM
#5
84SE-EGI helpy-helperton
You didn't tell us much about which model you have, but when the trans mount sags over time (or lets loose), it can sometimes allow the driveshaft collar to impact the tailpipe heat shield under certain conditions. This would be heard as a scraping sound which increases with vehicle speed, independent of engine speed.
Maybe have a look at that and see if your heat shielding in that area is bent. Removal of the driveshaft isn't hard if you're trying to isolate the issue (4x10mm nuts/bolts at the 3rd member), but be aware that you'll get trans fluid leakage out of the trans tailshaft if you the car's on an incline toward the rear. Also, be sure to mark your 3rd member U-joint position on the rear axle input shaft so they go back together in balance.
Take a look at those things and reply back. Worst case is that you chipped a tooth in the 3rd member which would be felt as a vibration usually under acceleration and deceleration by nothing at steady state on a flat, smooth road. I doubt it's that just yet.
Maybe have a look at that and see if your heat shielding in that area is bent. Removal of the driveshaft isn't hard if you're trying to isolate the issue (4x10mm nuts/bolts at the 3rd member), but be aware that you'll get trans fluid leakage out of the trans tailshaft if you the car's on an incline toward the rear. Also, be sure to mark your 3rd member U-joint position on the rear axle input shaft so they go back together in balance.
Take a look at those things and reply back. Worst case is that you chipped a tooth in the 3rd member which would be felt as a vibration usually under acceleration and deceleration by nothing at steady state on a flat, smooth road. I doubt it's that just yet.
08-03-15, 02:42 AM
#6
Full Member
Thread Starter
Sorry, it's an 81 gsl. There didn't appear to be any contact between the shaft and the shield. The more I drive it the better it feels. Though the vibration is very present in the shifter at high spend speeds and can be felt in the pedals when the clutch is in there's very little noticeable shaking below 40 or so. Just a little noise like when it started.
08-03-15, 04:49 PM
#7
84SE-EGI helpy-helperton
If it suddenly goes smooth and quiet, that means you grenaded your pilot bearing. Happened to me a long time ago and surprisingly the car ran and shifted just great without a pilot bearing in place, but I don't recommend it.
Typical pilot-bearing failure symptoms are a grinding at any engine speed when the clutch pedal is IN (clutch disengaged), as the transmission input shaft and engine are moving at different speeds. This is also felt sitting at idle with the car in gear and pushing in the clutch, and is sometimes accompanied by rough shifting - as the pilot bearing is dragging and allowing engine/flywheel energy to continue to attempt to rotate the transmission, making shifting more difficult. All this goes away when you have the clutch OUT (as when driving) and the transmission in neutral - as the engine/flywheel/trans are all rotating as one unit, and the pilot bearing isn't spinning at all.
Typical pilot-bearing failure symptoms are a grinding at any engine speed when the clutch pedal is IN (clutch disengaged), as the transmission input shaft and engine are moving at different speeds. This is also felt sitting at idle with the car in gear and pushing in the clutch, and is sometimes accompanied by rough shifting - as the pilot bearing is dragging and allowing engine/flywheel energy to continue to attempt to rotate the transmission, making shifting more difficult. All this goes away when you have the clutch OUT (as when driving) and the transmission in neutral - as the engine/flywheel/trans are all rotating as one unit, and the pilot bearing isn't spinning at all.
Trending Topics
08-05-15, 02:23 AM
#9
84SE-EGI helpy-helperton
Okay - could be one of the transmission front bearings, or just simply the throwout bearing. Could also be the trans rear oil seal. Here's my thinking on these;
1) The front transmission bearings are sealed by an aluminum housing which looks like this
and it has a gasket which seals the trans fluid from leaking out the front. This could be where your trans fluid disappeared to, and would be evident from trans fluid leakage at the engine/trans interface. Pull that round rubber plug at the bottom of the flat section of the bell housing (an inspection port for the flywheel) and see what comes out. If a quart of transmission fluid comes out - there you go. Start by replacing the cover gasket, but check the cover to be sure it's not gouged by the throwout bearing motion, or otherwise damaged. A failed throwout bearing usually buggers up the smooth surface of the front cover, and you want that to be almost mirror smooth for the best clutch feel and function.
Here's the gasket:
Bearings are very long-lived and unlikely to have failed unless oil starved.
2) Throwout bearing - As to the vibration felt when you push the clutch in, this tells me that the balance of the engine/clutch/trans goes OUT when you separate the forces by pushing in the clutch and disengaging the engine from the drivetrain. The Throwout bearing is what controls the clutch cover springs and removes the engine torque from the trans. If your throwout bearing is going bad, this usually results in a scraping noise all the time - as the body of the Throwout bearing never rotates, as it engages the clutch fork and slave cylinder to prevent it from turning. An imbalance from a failed bearing would be felt through the clutch pedal as a vibration - as it's hydraulically connected to your left foot. There's a squar-ish rubber boot at the middle of the clutch fork where it goes through the bell housing which helps to isolate vibration from the fork actuating the throwout bearing - I couldn't find a Mazdatrix replacement for that, but it should be installed to prevent water/oil from getting into your clutch disk/flywheel.
3) Rear Trans Seal - I'm still wondering where that quart of trans fluid went. If the rear trans seal goes out, it will allow leakage there and will spray down the driveshaft and all over the rear of the underside of the car due to air flow. The rear trans seal would also allow fluid to get past the bearing, and your rear tailshaft bearing would be loud all the time if it failed. Like the trans front bearings, this is much less likely but worth looking into. rear seals have to be removed carefully and can be damaged by sloppy installation of a driveshaft, or a dirty shaft inserted into the tailshaft of the transmission which damages the rubber seal. It looks like this;
If I had to put $$$ on this, I'd bet it's the throwout bearing, given that the vibration is affected by the clutch being in or out. The other parts I mention would be making noise anytime the car were moving, and independent of the clutch for the most part. Have a look and reply back,
1) The front transmission bearings are sealed by an aluminum housing which looks like this
and it has a gasket which seals the trans fluid from leaking out the front. This could be where your trans fluid disappeared to, and would be evident from trans fluid leakage at the engine/trans interface. Pull that round rubber plug at the bottom of the flat section of the bell housing (an inspection port for the flywheel) and see what comes out. If a quart of transmission fluid comes out - there you go. Start by replacing the cover gasket, but check the cover to be sure it's not gouged by the throwout bearing motion, or otherwise damaged. A failed throwout bearing usually buggers up the smooth surface of the front cover, and you want that to be almost mirror smooth for the best clutch feel and function.
Here's the gasket:
Bearings are very long-lived and unlikely to have failed unless oil starved.
2) Throwout bearing - As to the vibration felt when you push the clutch in, this tells me that the balance of the engine/clutch/trans goes OUT when you separate the forces by pushing in the clutch and disengaging the engine from the drivetrain. The Throwout bearing is what controls the clutch cover springs and removes the engine torque from the trans. If your throwout bearing is going bad, this usually results in a scraping noise all the time - as the body of the Throwout bearing never rotates, as it engages the clutch fork and slave cylinder to prevent it from turning. An imbalance from a failed bearing would be felt through the clutch pedal as a vibration - as it's hydraulically connected to your left foot. There's a squar-ish rubber boot at the middle of the clutch fork where it goes through the bell housing which helps to isolate vibration from the fork actuating the throwout bearing - I couldn't find a Mazdatrix replacement for that, but it should be installed to prevent water/oil from getting into your clutch disk/flywheel.
3) Rear Trans Seal - I'm still wondering where that quart of trans fluid went. If the rear trans seal goes out, it will allow leakage there and will spray down the driveshaft and all over the rear of the underside of the car due to air flow. The rear trans seal would also allow fluid to get past the bearing, and your rear tailshaft bearing would be loud all the time if it failed. Like the trans front bearings, this is much less likely but worth looking into. rear seals have to be removed carefully and can be damaged by sloppy installation of a driveshaft, or a dirty shaft inserted into the tailshaft of the transmission which damages the rubber seal. It looks like this;
If I had to put $$$ on this, I'd bet it's the throwout bearing, given that the vibration is affected by the clutch being in or out. The other parts I mention would be making noise anytime the car were moving, and independent of the clutch for the most part. Have a look and reply back,
Last edited by LongDuck; 08-05-15 at 02:29 AM.
08-06-15, 12:50 PM
#10
Full Member
Thread Starter
I'm busy for the next week so I won't be able to get to this for a bit but I'll check those out. I did replace the throw out barring less than 2k miles ago with the clutch. I'm thinking the connection between the clutch and the vibration is that, without the connection between the engine to the wheels, it's less tight in the system. Thus it would have more room to vibrate... If that makes any sense.
08-06-15, 05:52 PM
#11
I'm busy for the next week so I won't be able to get to this for a bit but I'll check those out. I did replace the throw out barring less than 2k miles ago with the clutch. I'm thinking the connection between the clutch and the vibration is that, without the connection between the engine to the wheels, it's less tight in the system. Thus it would have more room to vibrate... If that makes any sense.
08-09-15, 08:02 PM
#13
Full Member
Thread Starter
OK sooooo, I replaced the trans fluid. There was plenty of flakes. Almost more like crème de la transmission. But when I took it for a drive everything seems better. No noise to speak of and the vibration is nothing more than I would expect from an old car. Plus it shifts better than before. Thanks for the input guys. I'll update again if things get bad again.
Thread
Thread Starter
Forum
Replies
Last Post