rearend shake/vibration on moderate accell

[Scott E]

At about40-50 mph,on a moderate accelleration sometimes I get a shake or vibration,feels like its coming from the rear end,I can mash the throttle and get trans to downshift and get thr rpms up and it wont do it,only at moderate accelleration and not all the time,any suggestions to what I am experiencing? Should I be looking at anything in particular that could be worn? Any thoughts or suggestion? Thanks in advance!

 

[FrankM]

It depends on the rpms you are at when this occurs.

If you are lugging the engine you could be experiencing a minor engine mis-fire or an exhaust vibration.

next time this happens see if you are in torque converter lockup, if so then just touch the brake to release it. You will see rpms slightly increase, if vibration goes away then I would not worry about it. You are just lugging the engine.

 

[bnhynum]

This sounds very similar to a problem I am experiencing. I have about 90k miles on my 95 and I get a slight vibration and increased whine at about 2k rpm. It happens most when cruising about 40-45 mph and the transmission is in overdrive. With slight acceleration the rpms increase but with no power gain and an increasing whining noise (I think from the transmission), finally at about 2200 rpms the transmission will downshift and I get a boost of power and speed. I do not experience this if I accelerate hard and force the downshift. The transmission shifts up normally quite well but I experience this on all downshifts. I had the transmission flushed and replaced the seal and filter myself with little to no change in the behavior. I have done almost every repair on my Vette myself but am scared to death of the automatic transmission. I drive my Vette almost daily and can live with the problem and like any frugal daily driver will wait until complete failure before performing most non life threatening repairs. I just wonder if I could be living with something that could be fixed easily and inexpensively. Any help would be appreciated.

 

[FrankM]

I do not experience this if I accelerate hard and force the downshift. The transmission shifts up normally quite well but I experience this on all downshifts. I had the transmission flushed and replaced the seal and filter myself with little to no change in the behavior. I have done almost every repair on my Vette myself but am scared to death of the automatic transmission. I drive my Vette almost daily and can live with the problem and like any frugal daily driver will wait until complete failure before performing most non life threatening repairs. I just wonder if I could be living with something that could be fixed easily and inexpensively. Any help would be appreciated.

You may have a failing torque converter. It slips in lockup??. You have the right symptons.
Go to a transmission shop and let them drive it.
It you continue to drive it the debris from the failing TC will damage the rest of the transmission. Now is the cheapest time to address it.

 

[Awhite66]

C2 rearend-shake-vibration-moderate-accel

Sounds like I have the same problem. My '66 was stored for 18 years before I did a complete body off restoration.
Now I have this rear end vibration. It occurs at the slightest acceleration load, and gets worse with harder accel.
All "U" joints were replaced, and the rear leaf spring was replaced with a composite spring.