spyder7724

i finally got rid of the gear whine i've had since i installe the 3.73's last fall. i tried two sets of gears and had it apart 3 times trying to rid the car of noise. this time(number 4 and gear set #3) i got it. i installed a set of motive 4.30's and set up the shims tight on the pinion and loose on backlash. if anybody need any specs just e-mail me. the techs at frpp said that the 3.73 gears will make more noise due to the tooth count and pitch of the teeth on the ring gear FYI.

DuBaI

i got a loot of whinning ya please send me the specs..
4:10 FRPP

BlowByRacing

backlash is different for every manufacture of gears - everyone besure to check that before just adjusting by ford specs.
Companys like: Motive Gear, FRPP, Yukon, Moser, Richmond, etc they are all different - just a little FYI

spyder7724

one thing i confirmed is that my carrier is not machined correctly. it is either .005" out casing the ring gear to wobble or it is causing the ring gear to turn eliptically. in any case my backlash varies by .005" while turning the ring gear 180degrees. i increased the backlash to a minimum of .010" on the tight area and max of.015" in the loose area. i also took a trick from justin @JPC racing. i started with the stock pinion shim this time disregarding the pinion depth gauge. i wish i had another posi unit to try cause i'm sure it would have cured the noise problem. i've setup lots of 8.8" rears and this is the only one i've had so much trouble with. justin told me they had one(05 auto) apart over 10 times and used 4-5 sets of gears and it still made noise when it left. all i have to say is thanks fomoco.

mustangman02232

the only reason gears whine is if they are not installed correctly, nothing to do with the teeth

spyder7724

tell that to the frpp technical staff.

FredTT

You guys are prob gonna be mad, but I bought 3.73 FRPP gears used (1 and a 1/2 years old). Had them installed today and no whine.

~Fred

spyder7724

i'm not mad at all i'm happy for you. mine has been a real PItA but at least they are quiet now and anyway if the 3.73's did make any noise i wouldn't have been able to justify switching gears again especially regarding my wife.

FREAKO

did you do a runout on the ring gear when it was installed? Its supposed to be .004 or less.....

Steven6095

Apparent carrier issue also with my car!! This may be more common than we all think