24 replies to this topic

[TerrA LX]

some gear sets (ratios) are noisy by design.

[Toranamat69]

I had the same prob with my LX with Brand new motive gear sets - 2 different ratios. I ended up changing the Pirelli rear tires to Goodyears and the noise magically disappeared:-)

Lucky I was changing diff ratio because I wanted a different ratio, not to actually get rid of the noise or it would have been an expensive waste of time.

Matt

[TerrA LX]

Yeah I had some tyre noise in the rear which everyone swore was bearings, maybe absolutly rule out any other possible cause.

[unclefestal34s]

hi guys looking for any help
I have a LX sedan with ford 9 inch with diff noise that i cant seem to fix it has had 3 different gear sets in it trying to ilimimate diff noise (gear noise)
i have had a reputable diff specialist do the job but still noisy.
has anyone had same problem if so possible fixes as im running out of ideas
Cheers
Chris

people always seem to forget the 9in is a heavy duty truck diff (and was slightly noisy in trucks anyway)and when modified into smaller cars you always get some noise..
generally speaking if use factory ford gears they can be less noisy even worn my diff guy tells me something to do with the metal ford used...
i've used all the after market stuff including strange,richmond and motive gears..richmond are by far the most noisy...i find you'll always experience noise especially when going up the ratio's 3.77s and upwards ..motive gears are by far the less noisy one's on the market..

[rexy]

Step 1, borrow some rear wheels and tyres from a quiet car and see if your noise goes away.
Step 2, change oil to a straight 140 weight and add friction modifier of your choice. I have used the ford motorsport and nulon stuff with good results.
Step 3, add undercarpet insulation, preferably double layer bitumen containing stuff.
If you still have a bothersome noise then your gears may be at fault (or wheel bearings/unis etc..)
In my experience none of the cars with 3.7s or less eg 3.25 should have an audible whine from inside the car.
Good luck.

[ls2lxhatch]

The factory springs do not have an insulator at the diff but there is usually a rubber insulator between the spring and the body.

Rare Spare now sell reproduction spring to body insulators H1117 REAR SPRING INSULATOR KIT HQ-HZ, LH-UC.

Edited by ls2lxhatch, 22 July 2011 - 09:24 PM.

[ozyozyozy]

back lash and pinion height are critical to the amount of noise generated. the 9 inch diffs are prone to gear noise.
as was mentioned before the best gearsets to use are the genuine ford and ford motorsport gear sets.
iv used iron and alloy housings, havent noticed a difference between the two.

[AbsynthHatch]

I've had qiute a few 9 inch diffs in various models falcons and in a couple of Holdens, none ever had noise problems, ratios from 2.78 to 5.14

Gear boxes yes, other driveline components yes

I would get a second opinion or beg, borrow and err... off some mates and substitute driveline components till I eliminated the noise

[rodomo]

An educated guess would be 0.

[S pack]

An educated guess would be 0.

+1
no toe in or toe out on a live rear axle.

[rodomo]

hey guys just had car wheel alighned again and rear has 4.5 mm - toe

This could probably be enough to cause mechanical/and/or/tyre noise.