Vibration at 3000 rpm after MM replacement - might have found something
10-24-2007, 02:56 AM
#46
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You really do not have to drop exhaust or the lower-bell housing.
You can release and inspect the flex plate spline clearance thru the "inspection" hole.
12 volt bulb, socket and wire to throw some light on things. Have helper rotate crankshaft (CW looking at front of engine) line up cap-head bolt with inspection hole.
(Mark crank pulley with sharpie for easy bolt line-up next time)
You can release and inspect the flex plate spline clearance thru the "inspection" hole.
12 volt bulb, socket and wire to throw some light on things. Have helper rotate crankshaft (CW looking at front of engine) line up cap-head bolt with inspection hole.
(Mark crank pulley with sharpie for easy bolt line-up next time)
10-24-2007, 03:10 AM
#47
Team Owner
Hi Ed , I was referring to the the pinch bolt that connects the rear of the driveshaft to the torque converter, you do have to remove the exhaust and center heat shield to check this bolt, if its loose then the drive shaft might be able to move
10-24-2007, 03:08 PM
#49
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Piccardo, do yourself a big favor and check the endplay on the crank while you have the cover off the bottom and the clamp is loose. Since you've already seen the extra drag and effects of the thrust load on the crank, you may already be on the way towards a thrust bearing failure. If you catch the wear before it gets too severe, you can recover now with just main bearing replacement. If the wear gets much beyond specs, the crank will displace to the point where it fractures the bearing web, making the block a very large doorstop.
There are numerous threads and how-to's on tips sites showing how to check crank endplay, so I won't repeat them. With a simple dial indicator and a clamp or magnetic base, the check takes mere minutes more as part of the clamp release effort. Catch the thrust bearing wear early and it's a relatively inexpensive fix, compared to finding another engine. Don't delay!
There are numerous threads and how-to's on tips sites showing how to check crank endplay, so I won't repeat them. With a simple dial indicator and a clamp or magnetic base, the check takes mere minutes more as part of the clamp release effort. Catch the thrust bearing wear early and it's a relatively inexpensive fix, compared to finding another engine. Don't delay!
I remember that my 90 model was turning over slowly and started to make a strange whiring noise. To me it sounded like a bad accesory, like a smog pump. Released the pressure of the flex plate and presto noise was gone, and the engine turned over a bit faster too. So it stands to reason that releasing flex plate tension reduces cranck shaft friction..... Last week I noticed a vibration during acceleration at about 3k RPM. I took her out again today and it seems to have gotten worse. It is almost exactly at 3k under load and fades gradualy above this RPM. I will release tension on the flex plate (again) this weekend to see what if anything changes.
10-24-2007, 10:21 PM
#51
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Checked my crank endplay and...
Everything is fine
I mesured .0065".
That's in the spec (between .0024" and .0076", with the wear limit at .016").
Now I will check the flex plate quite often. Maybe once a month or so. More than once a year for sure. That's if I don't try the "Locktite Fix" next spring when I'll take the car out. I know that the real solution to prevent the drive shaft to bend the flexplate would be to intall Mr. Constantine clip. But I'll wait untill I will need to work on the Torque tube (removing it). I can wait...
Thanks to Bill Ball for the good procedure.
https://rennlist.com/forums/showthre...&highlight=tbf
I mesured .0065".
That's in the spec (between .0024" and .0076", with the wear limit at .016").Now I will check the flex plate quite often. Maybe once a month or so. More than once a year for sure. That's if I don't try the "Locktite Fix" next spring when I'll take the car out. I know that the real solution to prevent the drive shaft to bend the flexplate would be to intall Mr. Constantine clip. But I'll wait untill I will need to work on the Torque tube (removing it). I can wait...
Thanks to Bill Ball for the good procedure.
https://rennlist.com/forums/showthre...&highlight=tbf
11-06-2007, 07:27 PM
#52
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Checked endplay 3 times .007 was the most i could get out of it. I understand that .016 is the limit? In any case I should be fine. Big thanks to Bill Ball for the very detailed write-up and Doc for the kick in the pants to get it done.
