I have been trying to get find the source of a drive train, seat of the pants, vibration that my 79 z/28 with a four-speed transmission has for as long as I can remember.
It probably is going to end up being one or more of the retro Goodyears, which have about 600 miles on them, not being able to be balanced.
The best test is next week when a garage friend of mine is going to swap the rims/ tires off of his sons 79 Trams Am onto the Z/28 and see if the vibration goes away.
Quick recap; it is a 31k original mile Z/28 that I've had since September 79 -it was a June 79 build.
I checked the pinion/ shaft angles and they appear to be OK. I did change out a bad rear transmission mount.
The vibration is at just over 60MPH, and most often I just run around town, so it hasn't been a major issue, but I want to get it fixed.
The vibration was there with the original Uniroyals and seemed to be the same or maybe a little better when I got the new Goodyears -so last year I actually had the Goodyears road force balanced to see if it could be fixed and they actually seemed a little worse..
One thing that I had thought was that one of the original rims may have been the problem - I did change one that they said was out of round years ago and it made no real difference.
I also wondered if the drive shafts for the auto and standard were the same length, and did find that the M21 Borg Warner T-10 had its own driveshaft part number -PN 7819345. So another longshot question is if they put in the other drive shaft PN 7819344, if it even fit, could that cause a vibration in the driveline?
I'm not sure where i can find the lengths etc., to compare.
My drive shaft has two 1" wide yellow stripes about 5" apart.
Anyone know if that could be an issue?
Now it is possible that everything will hopefully be sorted out when we do the rim/ tire swap testing.
If no vibration, we can swap in mine one at a time and find the bad one for sure -fingers crossed.
It probably is going to end up being one or more of the retro Goodyears, which have about 600 miles on them, not being able to be balanced.
The best test is next week when a garage friend of mine is going to swap the rims/ tires off of his sons 79 Trams Am onto the Z/28 and see if the vibration goes away.
Quick recap; it is a 31k original mile Z/28 that I've had since September 79 -it was a June 79 build.
I checked the pinion/ shaft angles and they appear to be OK. I did change out a bad rear transmission mount.
The vibration is at just over 60MPH, and most often I just run around town, so it hasn't been a major issue, but I want to get it fixed.
The vibration was there with the original Uniroyals and seemed to be the same or maybe a little better when I got the new Goodyears -so last year I actually had the Goodyears road force balanced to see if it could be fixed and they actually seemed a little worse..
One thing that I had thought was that one of the original rims may have been the problem - I did change one that they said was out of round years ago and it made no real difference.
I also wondered if the drive shafts for the auto and standard were the same length, and did find that the M21 Borg Warner T-10 had its own driveshaft part number -PN 7819345. So another longshot question is if they put in the other drive shaft PN 7819344, if it even fit, could that cause a vibration in the driveline?
I'm not sure where i can find the lengths etc., to compare.
My drive shaft has two 1" wide yellow stripes about 5" apart.
Anyone know if that could be an issue?
Now it is possible that everything will hopefully be sorted out when we do the rim/ tire swap testing.
If no vibration, we can swap in mine one at a time and find the bad one for sure -fingers crossed.