corvette95

I hear a noise..a whine from somewhere under the car. ALL of my fluids were just changed by me, trans, rear end,brakes,clutch fluids etc. Car had been sitting up for a few years while under repair. I can tell from which side or corner its coming from. Sounds like trans might sound low on fluid but I know its full and fresh. How is the best way to diagnose this?
Wheel bearings could be problem but they feel tight.

WW7

Best way I know of to find something like this is to put the car up on a lift , put it in gear, and listen under the car to see where the sounds coming from.. You need to have the rear wheels up where they belong so theres no damage to the universals , you can do this by using stands under the rear suspension..With the car up in the air running you should be able to pinpoint where the sound is coming from..WW

C409

..... First , make sure the neighbors cat didn't wind up tangled in a u-joint ..... Second , if the noise was NOT there before you serviced the car you might want to verify that the correct oils were used primarily in the trans ... I have noticed several threads on the forum regarding just that ... which oil to actually use in the ZF gearbox ....... If it is a cat the good news is the whining will stop ... the bad news ... well , someone should tell Sarah about Fluffy ................

corvette95

My lift is tied up, maybe I will do it with jack stands. Thanks!

WW7

Jack stands will work if high enough, Take a large screwdriver under there with you. Once you find the area the sound is coming from sometimes you can pinpoint it exactly with the screwdriver to your ear touching the metel end to the car...WW

proracr

If you use the jack stands, please insure that the car is one hundred percent stable before doing this evolution. You absolute do not want the car to jump off the jack stands with the engine running and the transmission in gear. And do not get under car when it is in this situation. OK, I'll stop freaking out now from the mental picture of your Vette jumping off the jack stands and running amok in your neighborhood!

I have owned my 94 convertible for about two months now and I have noticed some subtle "gear whine" from the gearbox when driving it and haven't been concerned about it as I think that it is normal with this transmission. It isn't very loud, but it's there. I just bought some ZF6 syncromesh gearbox oil from a fellow Forum member and intend to change the gearbox oil soon as my Vette has just a tad over 46,000 miles.

I remember when I was in the SCCA back in the 1990's and hearing the very loud whining noise emanating from the race cars that had square-cut gears in their racing transmissions. You could hear it over the loud exhaust from the race cars and it was a normal sound from a gearbox with square-cut gears.

Anyone with a ZF transmission in their C4 please correct me if I'm wrong.

For 93Rubie, I do not drive my Vette hard. I got that out of my system with four seasons of road racing in the SCCA driving open wheel formula cars and Nissans. Just hit 64 years of age last September and my reflexes, eyesight, etc. aren't what they used to be so I have dialed back the volume on my go-pedal. Still drive spiritedly, but not crazy. It's easier on the car and my wife's nerves so I think that the ZF6 Syncromesh will be sufficient!

93Rubie

Some gear noise in the ZF is normal, especially in the earlier ZF6's. 89-late 93? The later ones where quieter but did not handle as much torque. The difference is in the way the gears are cut. Another reason we have dual mass flywheels is to keep the noise at a minimum. Mine most noticeably has some noise in 1st at low speed. In 6th as well, when in a float situation (not coasting, or accelerating). Has some noise in all gears but is normal. Kind of like the old Muncie M22 Rock Crushers, but not as bad.

How do you drive your Vette? You may want something better than GM Syncromesh in your ZF.

kimmer

Make sure the wife or girl friend isn't under there.

corvette95

or maybe..............

WW7

Yeah man.Accidents do happen......WW

proracr

Only if the wife/girlfriend nags a lot!

corvette95

Taking my car to a friends shop today, raining like heck in Alabama, my lift is going to be tied up for a while, I will post results, I just hope I can find it, cant really spin the front tires on the lift, so hope its not FRONT wheel bearings.

corvette95

Put it on lift, noise seems to be going away. The car had not been driven in a LONG time. Couldnt hear noise on lift so I am thinking FRONT wheel bearing since I couldnt spin the front wheels fast on the lift.