Quiet 9” set up
07-09-2018, 01:29 PM
#1
Quiet 9” set up ive tried different sets of gears in my 9” and been unable the get it as quiet as i would like(factory quiet in an f-body). It is a moser 9” with wavetrac and 3.50 gears. Is anyone in the houston area about to set these up?
07-09-2018, 01:44 PM
#2
TECH Addict
Use a high of a zinc content NON SYNTHETIC lube as you can find,, it will help burnish the gears in and they run smoother.
the 75w90 from a farm store for tractors is one cheap source..
For fresh gears, you need to break them in for the first 500 miles with lots of short lugging style high load cycles,
keep track of the rear temp, you don't want to cook the lube.
The wave-trac is not the smoothest of posi rear ends until they break in,,
I think its a surface mating process kinda like a clutch break-in..
For limited slip clutch or cone rear ends I used to do about 50 figure 8's at low speed (20 MPH tops) before I head out
on the road/track to start them breaking in. Now I use a selectable locker or a Detroit. Gave up on clutch packs.
(I do more 4x4 than other uses, and got used to a ARB or E-locker's "hard" spool up.. )
Good luck,,, Oh and 4x4 shops do way better bear setups than generic shops in my experience.. YMMV.
the 75w90 from a farm store for tractors is one cheap source..
For fresh gears, you need to break them in for the first 500 miles with lots of short lugging style high load cycles,
keep track of the rear temp, you don't want to cook the lube.
The wave-trac is not the smoothest of posi rear ends until they break in,,
I think its a surface mating process kinda like a clutch break-in..
For limited slip clutch or cone rear ends I used to do about 50 figure 8's at low speed (20 MPH tops) before I head out
on the road/track to start them breaking in. Now I use a selectable locker or a Detroit. Gave up on clutch packs.
(I do more 4x4 than other uses, and got used to a ARB or E-locker's "hard" spool up.. )
Good luck,,, Oh and 4x4 shops do way better bear setups than generic shops in my experience.. YMMV.
07-09-2018, 01:48 PM
#3
Ford factory gears are the best place to start. A little noise is very common tough in a 9. I set my 3.50s up and they are quiet (I believe so anyway as the Kooks True Duals were loud). With this turbo conversion, I may find they are slightly louder than I think.
07-09-2018, 03:35 PM
#5
TECH Addict
Yukon are very strong and HARD gears,, they break in really really slow, and don't seem to
burnish out as smooth as the old factory Dana Spicer or FOMOCO gears did..
Also ,, there isn't really any such thing as a 9" gear set any more,, the current gears are
not cut the same angle and are actually a metric machine spec, From what I've seen they are using a
8.8" gear billet with a different CNC program.. But the sets seem to be optimized for less drag,
which means less quiet.. Way back they used to sell "quiet" gears,, and "Drag" gears. But haven't
seen that in a Long time..
burnish out as smooth as the old factory Dana Spicer or FOMOCO gears did..
Also ,, there isn't really any such thing as a 9" gear set any more,, the current gears are
not cut the same angle and are actually a metric machine spec, From what I've seen they are using a
8.8" gear billet with a different CNC program.. But the sets seem to be optimized for less drag,
which means less quiet.. Way back they used to sell "quiet" gears,, and "Drag" gears. But haven't
seen that in a Long time..
