I chickend out and took my 72 in for a new rear gear 3.73 Richmond.

It has now twice come back with a whinning noise comming form the rear and it does not make noise if I down shift only when I am crusing and it goes away if I get on it.

Any ideas what could be causing this, and what I can do to fix it.

Bernie--

My experience is that lower (numerically higer) gears are more likely to whine. Also, when I went to 3.42s in my car, the guy who built my rear insisted on using a Motive Gear ring & pinion, he says they are quieter than Richmond. My 3.42s howled just a little bit for the first 100 miles or so, but once broken-in, they are perfectly quiet. Hopefully yours will get quieter.

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Mike Newby

69 Chevelle 355/TH200-4R
97 Grand Prix GTP
64 Chevy C10 Pickup
79 Suzuki GS550

My Richmond 3.73's still whine after a couple of years and several different types of gear lube as well as rechecking the backlash and pattern match. It is only in the "float" condition you describe. It hurts nothing but is annoying.

Troy.

Troy,

What do you mean by float condition??

Bernie--

Depending on whether you are slowing down, running a steady speed, or accelerating, the howling gets louder or goes away. By "floating" Troy is probably saying they make the most noise when he is cruising with only a very slight throttle opening, or coasting to a stop without the brakes. That is the same conditions as when my old 3.55s were loudest.

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Mike Newby

69 Chevelle 355/TH200-4R
97 Grand Prix GTP
64 Chevy C10 Pickup
79 Suzuki GS550