4.6L Taxi cabs (3.55 gear whine)?

[N A]

I had to take a taxi this morning to a business meeting in town. The cab was a former Law Enforcement, '98-up CVPI. In traffic I couldn't hear the gears. When the street opened up, I could hear the rearend gear whine. Do 3.55:1 gears whine "lightly"? (My 3.08:1 are silent in my GM. I had an IROC-Z in high school with 4.10:1 gears and I know what gear whine sounds like).

[DuceAnAHalf]

Might have had 3.27s also. The rear end might have been rebuilt. originally my 3.27 were silent, after i had a trac-lok installed and the whole rear end rebuilt, the same gears whine now when accelerating. I chalk it up to a pinion on the low side of the torque spec. So far about 10,000 miles and no failure.

[zwack88]

My stock 3.55's have no whine. I have Trac-loc also.

[N A]

Now, I'm confused. If the pinion is set dead-on, no whine at all? How do you get "silent operation" from the rearend?

[DanHool]

3.55 and no whine

[DuceAnAHalf]

Now, I'm confused. If the pinion is set dead-on, no whine at all? How do you get "silent operation" from the rearend?

if the pinion is too loose it will whine, if it is too tight it will whine for a short while, then fail. just have to set up everything within spec, for whine free operation.

[N A]

Thanks, I'll keep this information in mind when I have my gears done.

[gadget73]

Mine vibrates but its a combination of worn rear bearings and out of balance driveshaft. No whine per se just a hum at highway speeds.

[N A]

I rode in the back of another 4.6L car (Taxi) last night. No gear whine, but it felt strong. I want to race one soon.

[GoodSamaritan]

On a side note, if gears are off even by the least little bit they will whine.
I used to work for a company that had to eat a shipment of 500 gearboxes (forklift transmissions) because they whined. They tore down several of them and the QC guy verified that they were dead on. They finally had to start putting polishing compound on the gears and run them at 1200rpm speed for 20 minutes while the gearbox was partially assembled until they quit whining. They then cleaned them, finished putting them together and filled them with oil. They were absolutely quiet after that. I never heard of a single return after that.

Some of you might also be familiar with gear whine from a set of solid timing gears (vs chain). Actually it surprises me that more diffs don't whine a bit after a gear swap. The fact it doesn't speaks volumes for the design and mfg of the diffs and gears themselves.

[N A]

I don't want any gear whine when I do my gears.

[GoodSamaritan]

O.T.
I had a 76 Plymouth GranFury that had a whine in the rear for over 20 years. (It was in the family since it was almost new) Finally one day my mom was in it and the rear end locked up, stranding her on the railroad tracks. Fortunately no trains were coming. It seems that Ma Mopar forgot to tighten the bolts on the ring gear. When I took the carier out of the diff, I took the remaining bolts out of the ring gear with my bare hands! One of them had finally worked it's way out and happened to land in the spider gears as mom slowed down to go across thr railroad tracks in town. $50 and a junkyard diff, later the car ran for another 2 or three years, until some 17 y/0 girl t-boned it, but that is another story.