Gear Shift Movement
Thread Starter
Pro
Joined: Dec 1999
Posts: 673
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From: Venetia,Pa,USA
Gear Shift Movement
I just had my 92 6 speed vette for it's first outting of the year. I jumped on the gas in first and noticed that the gear shift moved up about a 1/2 an inch. It did the same thing when I jammed it in second and third. Is this normal and I never noticed it before?
Safety Car
Joined: Feb 2000
Posts: 4,564
Likes: 109
From: Austin Texas
Re: Gear Shift Movement (The Bus)
It is usually indicative of the driveline beam being loose.
If you want to save some money over the beam-plates that the ZFDoc produces, get some 3/16" sheet steel and cut some plates that will span both bolts (front & rear, top & bottom). Drill them out and install them between the bolt & the beam.
What the plates do is distribute the force of the bolts across a wider surface. It makes a big difference in the stability of the car as well. Many have reported less rear-end kick-out under hard acceleration with them installed.
If you want to save some money over the beam-plates that the ZFDoc produces, get some 3/16" sheet steel and cut some plates that will span both bolts (front & rear, top & bottom). Drill them out and install them between the bolt & the beam.
What the plates do is distribute the force of the bolts across a wider surface. It makes a big difference in the stability of the car as well. Many have reported less rear-end kick-out under hard acceleration with them installed.
Safety Car
Joined: Feb 2000
Posts: 4,564
Likes: 109
From: Austin Texas
Re: Gear Shift Movement (The Bus)
Let me see if I can explain this without visual aids....
When the bolts for the support beam are over-torqued, the beam actually pinches in at the point where the bolts contact the beam. When this happens, you have only a small point of full contact between the beam and the transmission.
GM added an RTV-type substance between the beam and the trans at the factory to help fill the voids and stabilize the driveline beam. Originally, it bonded the beam to the transmission, and I remember the mechanic removing it for the first time cussing up a storm because it wouldn't come out. This substance gets removed over time as the beam is removed/installed for service.
If you add a beam-plate to the bolts, you take the point-loads and spread them out over a wider space. This makes the beam, which is aluminium, stronger. The forces are distributed, and the beam will not flex under loads.
Make any sense now?
When the bolts for the support beam are over-torqued, the beam actually pinches in at the point where the bolts contact the beam. When this happens, you have only a small point of full contact between the beam and the transmission.
GM added an RTV-type substance between the beam and the trans at the factory to help fill the voids and stabilize the driveline beam. Originally, it bonded the beam to the transmission, and I remember the mechanic removing it for the first time cussing up a storm because it wouldn't come out. This substance gets removed over time as the beam is removed/installed for service.
If you add a beam-plate to the bolts, you take the point-loads and spread them out over a wider space. This makes the beam, which is aluminium, stronger. The forces are distributed, and the beam will not flex under loads.
Make any sense now?
