need advice. what's the most common cause for gear whine?

[axeman]

i just installed new gears last week. the gear pattern looked fine and i set the backlash to 0.013. anything from 0.008 to 0.015 is within spec according to my manuals. why the heck are they whining? is it possible that my backlash has loosened up a bit and now it's not within spec? i'm just curious what the most common cause is for gear whine. little help here please.

 

[arbailey]

What brand are they? I've heard that Richmond Gears whine. I also heard the best (quietest) ones are the Ford Motorsports ones.

 

[axeman]

What brand are they? I've heard that Richmond Gears whine. I also heard the best (quietest) ones are the Ford Motorsports ones.

they are ford. i bought them used from a friend of a friend. he assures me there is only 1000 miles on them. do you think i should just tighten the backlash up a little? maybe 0.010"

 

[thompsonsd]

Ouch... I had this problem. I'd love to give you the magic answer but after installing and re-installing them myself several times I gave up and paid the local speed shop to do it...

 

[stangbear427]

And when the speedshop did it, it went away?

 

[Michael Yount]

Used gears are always a bit of a crapshoot; I've seen them set up incorrectly, and run long enough to have wear patterns established such that no matter what you did with set up/backlash/pre-load they made noise -- so that's a possibility. You mention the pattern and the backlash; was the pinion pre-load and the crush-sleeve done properly?

 

[stangbear427]

Why I will never attempt to install my own gears...

 

[axeman]

Used gears are always a bit of a crapshoot; I've seen them set up incorrectly, and run long enough to have wear patterns established such that no matter what you did with set up/backlash/pre-load they made noise -- so that's a possibility. You mention the pattern and the backlash; was the pinion pre-load and the crush-sleeve done properly?

pinion preload and crush sleeve were set up fine. the majority of the noise seems to only occur between 2000 and 2500 rpm in 4th and 5th gear. the sound is mostly audible during acceleration and deceleration. during coast(trying to maintain a speed) it almost wants to go away. but also when i barely give it some gas or let off the gas you can really hear it.

the gears i put in are 4.30's if that helps at all. i've heard before that the lower the gear the more often you end up with some noise. is that true?

do you think that 0.013" is too much backlash?

 

[sleeper89]

sounds like they either aren't lined up quite right or maybe had a bad pattern worn in them. i'd try to double check/reinstall everything (pita) and see if that fixes it. if not you may be SOL. i had used gears from a turbo coupe put in mine and they whine in a fashion similar to yours. i just learned to live with it 'cause the rear is probably getting swapped soon anyhow.

-steve

 

[speed1972]

as long as all of your tolerances were correct when you put it together, there isn't a whole lot you can do.. thats one of the joys of buying used gears. more than likely they were set up wrong in the old car. I've put together probably 50 rearends and the only ones that whine are the ones with used gears. I personally bought a set of used ones for mine and they whine too. Everything was within specs but there is nothing you can do when they've already got a bad pattern worn in them. You're backlash is within spec so I wouldn't worry about that. Now if you know the gears didn't whine in the previous car, you would need to look at pinion depth.... but if it isn't bad, don't worry about it and take it as a lesson learned.... Larry

 

[PURESTREET5006]

That why i use FMS gears in my car...Iv'e had some new & used gears before and you can always use the .027 shim and it sets up perfect for us.Thats what the gears are in the 8.8's when they come stock with 2.73's 3.08's or 3.27's the only problem that you run into is putting that kingpin back in the carrier with 4.30 or bigger gears,you would have to notch that pin.

 

[90 lx convert]

Pinion depth has alot more to do with it than backlash. I'd say it's time for a pinion depth tool. That's probably the only thing that would help now. I have set up used gears before and never had a problem, you just never know. Mike

 

[axeman]

well, i do have a dial indicator gauge that i used to read backlash. you hook it up to a big magnetic base that has extendable arms on it.

i did check the wear pattern and it looked fine. how else can i check pinion depth? what should it be?

have you guys ever heard of backlash loosening up a bit. while driving it, it almost sounds as if there is a little too much play back there. you can hear it when you are lightly on and off the gas.

 

[ironmedic]

i have new gears and they started to whine. my friend installed them and they never whined when he owned my stang. i used to ride with him alot too. after i bought it, the gears started whining LOL! talk about a PITA! i learned to live with it.