'92 Vibration at acceleration

[Tim Scales]

I have a 92 LT1 with the Automatic "Tranny". It has 115,000+ miles now and had 17,000 when I purchased 8 years ago. 90% of the miles are Highway or road miles. When I accelerate at highway speeds (50-70) it will vibrate until I either give it more pedal, less pedal or "Tap" the brake. I also had a 91 and 86 that did the same thing but only have the 92 now. all 3 had realativly low miles and I noticed all doing this. I was told by several Corvette people that this is "Normal".
Has anyone else had this? It seems to me to be the torque converter not "unlocking" fast enough. If there is a "Cure" I would appreciate knowing it. I love this car and want to keep her for the "duration". But don't want to spend a lot more on it either...thanks for any advice I can get, Slickman (Tim)

 

[grapeknutz]

There are two things to look at 1 is the torque converter clutch is going bad 2 and, or the lock up solenoid is going bad.

 

[Tim Scales]

There are two things to look at 1 is the torque converter clutch is going bad 2 and, or the lock up solenoid is going bad.

Thanks for the info..I will take 'er to my tranny man while in town. Tim

 

[vee93]

Ya know..., it could be as simple as a defective tire or improper tire pressure----or the tires/wheels might need balancing. Could also be worn wheel bearings, ball joints or tie-rod ends.

 

[Tim Scales]

Could be...but I have had it on ALL C4's I've owned. The 92 has had 3 set of tires in 115K and have it checked by the aligment shop all the time and rotate and balance the tires frequently as I drive 'er back and forth to Indiana 2-3 times a month. Thanks, Tim

 

[G Winter]

I believe it points to the lockup device. They are set up to unlock when you
touch the brake. If you keep your foot on the throttle and touch the brake
just enough to activate the switch you should get the same results as when
actually applying the brakes. It might be common but I don't believe it is right, and should be repairable.

 

[Tim Scales]

Thanks Scav, I too think it is in the trannny lock up somewhere. If I can get all my other chores seen too before Sat I will take er to my trans shop. Thanks.

 

[Robertwav1]

I have the same problem on my 93 and noticed it several years ago on a trip down south. I really forgot about it since it's only noticable on accel. at those speeds. There was a thread on this before and I do believe that lock up sol. was mentioned. hmmm....maybe time to re-look this up again! Winter is comming.

 

[jmccloud]

50-70 vibration

Yes there were several threads on this, perhaps 2 years ago. I contributed to one of them.
I had 3 Buicks that had the symptoms that you describe. Every one of them was cured by replacing the spark plug wires. The first one was correctly diagnosed by the local dealer who charged me $108 (as I recall) for the diagnosis and one plug wire. When the other cars acted similarly, I replaced the plug wires myself.
Try it, it might be your problem.

 

[Tim Scales]

Thanks Men!
I took 'er to the tranny shop and had them remove the pan to change the filter and fluid as it was due anyway.
While there I began " looking and feeling around" and found the pressure valve/solenoid was a little loose. I had the mechanic take the solenoid out to inspect for cracks and nothing appeared wrong. He reinstalled and tighened it down good and guess what? No more VIBES!!!!! The solenoid or switch has to be "sealed" to operate properly. apparently the person putting this together at the factory was not tightening them down enough or they are coming loose from vibration over a short period of time. Anyway, I have got it going fine now. just returned to Indiana from Alabama with no problems. Thanks, Tim