Rads

My '86 with LSD has a high-pitched, variable (weeoooweeoooweeooo etc) whine audible only on the road with the car warm, generally above 20MPH, minimally louder recently. I've checked everything I can think of including parking brake, CV's, brakes etc. I can shut the engine off and still hear it, coasting. No change with slalom turns, not a typical bearing growl. My next thought is to replace the diff oil in case I got the wrong type last change. Any thoughts? Can't reproduce it in my garage, recently replaced the fuel pump with an 044, no difference.

RADS

Zermatt Silver, Vitesse 2, single owner from day 1

snappy

ex wife maybe?
on more serious note, i had a slight wine as well, turned out they did not fill my dif oil to the correct level.

Ian Carr

You might have low trans oil. My 5th gear has a whine, im not sure what its from.

lart951

Ian, could be the extra weight

Ian Carr

And now you know why i never post in the 944 turbo section

lart951

Don't make me feel like an azz

Back to topic. My 2nd 951 had a similar whine when I was on the fwy and let go of the gas, but I replace the tranny oil with red line and the whine was gone.

Rads

Thanks, guys. Snappy, I backed it up this morning and didn't find my ex. Tomorrow I'll check the tranny oil and probably replace it. I think there's synthetic in it at the moment, and a number of people at the track have told me they don't like synthetics for the rear end.

RADS (currently in Estero, FL for the winter)

'86 Zermatt silver, Vitesse Stage 2, single owner since June 10, 1986

Andy

Not knowing what it really sounds like, I'll throw this out as a possibility.

Tire noise. My Kumho Ecsta Supras began making so much noise that I replaced my rear wheel bearings, my mechanic even thought that's what it was...

Good luck.

Rads

Final answer:

Up on the lift with the wheels turning at about 60MPH, the left rear wheel proved to be the source. The tranny oil was good, filled to the top, and review of my old service reconds showed Sepco, left that alone. A defective, scored left rear hub proved to be the culprit. Who'd guess?

RADS

Zermatt Silver '86 951, Vitesse Stage 2

ehall

Since you have it solved, allow me to add one thing.
lart told me that when he doesn't oil his tranny just right, sometimes he/she will whine all night as well.