bonnettoboot
New Member
For my first post i'll keep it simple!
To get you away from these nebulous electronic problems I thought you might enjoy wrapping your minds around this tranny problem. A Customer of about 2 years called about a year ago, the vehicle was vibrating a lot and asked what was. A few weeks later he called and said it was bad he was coming in. He was about a mile from us when the front drive shaft came off. Luckily, little damage was caused and we refitted it. A week ago, he again called, a bad vibration again he was coming in by tow truck. We put it up and found the drive shaft loose again, also the front damper was hanging on 1 bolt, Refitted and tightened everything and drove it, It made a strange banging sound on starting and at 2000 the vibration was severe, over that it was much less, at idle it was smooth and quiet. We pinpointed the source in the transmission the btrake drum was actually shaking. so off came the T/fer box cover, nothing seemed wrong! Ran motor again without T/Box and it was still there but now seemed to be in the transmission/bell housing. We decided to pull out the whole unit. In the meantime I looked up alldata and was surprised to find TSB 86/08/01/NAS regarding balance weight on the flywheel- this vehicle was supceptible-. Looked and could see NO balance weights. Aha, we thought, they had obviously come off and caused the noise and vibration etc, Out with the unit. Every bolt associated with the unit was loose. First surprise, it had had a used unit fitted. But there was no sign of weights on the flywheel at all? Now we pulled off the flywheel as the flex plate looked cracked, it fell off in peices, from the wear marks it had been totally broken for a long time. Was this the cause or the result? Then I found TSB 44/01/00/NAS, this describes various spacers for the various engines. For our VIN the one fitted was correct 7mm. We ordered a new flex plate and sent the Convertor out for checking. In the meantime I was intrigued by the fact that this flex plate had been able to drive the vehicle even thopugh it was totally broken, so I decided to look a bit closer. I'd noticed that the plate was a little conical but took no notice, UNTIL we got the new plate, there was almost 1/2" difference back to back, as if the old plate had been bent in position, We fitted everything together loosely and sure enough the plate was being pushed back about 3mm when tightened up. In fact if it had the 4mm spacer it would be correct!! It now seems that this trans was from an earlier model which had the 4mm spacer, the installers did not realize the difference and fitted it with the 7mm one, belling the flex plate as they tightened it. The vibration was always there and gradually got worse until the plate broke and created an unacceptable vibration. Out of curiosity I got a used flywheel from a local yard to check if it was different, it was exasctly the same EXCEPT, it had a balance weight screwed into it JUST 1. Now I had presumed that the earlier units had no balance wights as the flywheel seems to have the balance adjustment cast into it. We have ordered the spacer and new seals, and hope we are right! But i'm concerned about the balance weights, should it have them or not? Can anyone out there add anything to this? Bill Brady
To get you away from these nebulous electronic problems I thought you might enjoy wrapping your minds around this tranny problem. A Customer of about 2 years called about a year ago, the vehicle was vibrating a lot and asked what was. A few weeks later he called and said it was bad he was coming in. He was about a mile from us when the front drive shaft came off. Luckily, little damage was caused and we refitted it. A week ago, he again called, a bad vibration again he was coming in by tow truck. We put it up and found the drive shaft loose again, also the front damper was hanging on 1 bolt, Refitted and tightened everything and drove it, It made a strange banging sound on starting and at 2000 the vibration was severe, over that it was much less, at idle it was smooth and quiet. We pinpointed the source in the transmission the btrake drum was actually shaking. so off came the T/fer box cover, nothing seemed wrong! Ran motor again without T/Box and it was still there but now seemed to be in the transmission/bell housing. We decided to pull out the whole unit. In the meantime I looked up alldata and was surprised to find TSB 86/08/01/NAS regarding balance weight on the flywheel- this vehicle was supceptible-. Looked and could see NO balance weights. Aha, we thought, they had obviously come off and caused the noise and vibration etc, Out with the unit. Every bolt associated with the unit was loose. First surprise, it had had a used unit fitted. But there was no sign of weights on the flywheel at all? Now we pulled off the flywheel as the flex plate looked cracked, it fell off in peices, from the wear marks it had been totally broken for a long time. Was this the cause or the result? Then I found TSB 44/01/00/NAS, this describes various spacers for the various engines. For our VIN the one fitted was correct 7mm. We ordered a new flex plate and sent the Convertor out for checking. In the meantime I was intrigued by the fact that this flex plate had been able to drive the vehicle even thopugh it was totally broken, so I decided to look a bit closer. I'd noticed that the plate was a little conical but took no notice, UNTIL we got the new plate, there was almost 1/2" difference back to back, as if the old plate had been bent in position, We fitted everything together loosely and sure enough the plate was being pushed back about 3mm when tightened up. In fact if it had the 4mm spacer it would be correct!! It now seems that this trans was from an earlier model which had the 4mm spacer, the installers did not realize the difference and fitted it with the 7mm one, belling the flex plate as they tightened it. The vibration was always there and gradually got worse until the plate broke and created an unacceptable vibration. Out of curiosity I got a used flywheel from a local yard to check if it was different, it was exasctly the same EXCEPT, it had a balance weight screwed into it JUST 1. Now I had presumed that the earlier units had no balance wights as the flywheel seems to have the balance adjustment cast into it. We have ordered the spacer and new seals, and hope we are right! But i'm concerned about the balance weights, should it have them or not? Can anyone out there add anything to this? Bill Brady
