Question about Noisy Posi unit

[jdsent]

Hey Everyone,

Just got 373 gears installed and they make a humming noise when I'm driving at a consistent speed. Just wanted to kknow if that was normal.

I'm driving under 50mph for the first 500 miles I'm at 230miles now and I haven't been on the highway.

Will this noise get quieter as the gears break in?

Thanks in advance for the help!

[NJSPEEDER]

New gears often make noise. Get it to 500 miles and then do a fluid change and it shoudl quite down a lot.

-Tim

[jdsent]

Ok thanks. I never had new gears. The unit also has new clutch internals

[mustang51js]

keep an eye on them, mine never made any noise, doesnt mean its a bad thing just some people dont like the noise.

[Hotshot]

you are supposed to do duty cycles of approx 20 minutes then let them fully cool down then again and repeat process, never exceeding a certain RPM level for up till 500 miles.

Or it could be just a bad install. Guy over on AFM is on gear set #9 right now. 4 of them bad installs or inproper break in procedure

[hpwrestler220]

I have been told by numerous people and mechanics that there is no need to break the gears in. If they are installed correctly, they should not be making any noises whatsoever... Mine don't make a single noise...

Take it back and tell them to fix it.

Just think about buying a new car. Do you break in those gears lol? No. As long as gears are set up the right way, you can drive it however the heck ya want.

[Dark_Knight7096]

Could be a problem with pinion depth. Many of the people I know that have had gears installed have had them make noise, most of the time you can keep driving it without a problem, if the install was too outta whack you will have problems after a while (how botched the install depends on how long), if they were installed perfectly they shouldn't make much noise at all. Keep an eye on it, do as NJSPEEDER suggests and do a fluid change and see if that helps, if not they may not be installed correctly and I would take it back to the shop and voice your concerns.

[jdsent]

Thanks to all who posted so far. I will do the oil change after 500 miles and see what happens. I was told that the gears get hot and could chip. That is why the break in cycle is required. I will take them back if the oil change doesn't work.

[hpwrestler220]

Originally Posted by jdsent

Thanks to all who posted so far. I will do the oil change after 500 miles and see what happens. I was told that the gears get hot and could chip. That is why the break in cycle is required. I will take them back if the oil change doesn't work.

The only way i see them chipping is if they werent installed properly...

You definitely had friction modifier put in there?

[jdsent]

Yes I bought the friction additive from a ford dealership.