Nasty Hawk

. i had the BMR adj. torque arm and 3.73's put in about 4 days ago. took it out today and it started making a real loud HUMMING sound. it sounds like it is coming from the drive shaft and maybe the rear end, cant tell. the mechanic says my stock gears and posi unit were a little worn out, probly from hole shots with nittos and hittin juice in top of first gear.he just looked at it and says it is the posi unit, he says the gears are a little worn out. What do u guys thing. mods are below.

wrencher

iTrader: (2)

I'd say dont drive it & take it back to who installed the gears.
Let them look at it & see what is wrong.
It is prolly in the differential, namely the ring, pinion & the bearings, not the posi.

Joe "Preachers Sheets" DIESO

iTrader: (4)

My rear was toast when I got the car. I got a humming sound on the highway and it could be heard easier if I barely stepped on the gas, it was a humming/buzz sound. At really high speeds it was real loud but I was told that was my axle bearing.

The humming sound when I lightly pressed the gas was my gears (as I was told). Took a new set of gears to fix the issue and the meathead didn't install them right so I had to have them re-configured.

taqwache

if the 3.73s were installed only 4 days ago then they are not installed correctly. ask the mechanic what he set the backlash to. it should be between .004"-.008". also ask him to run a pattern on them to see if the pinion teeth are pushing on the middle of the ring gear teeth and if he used the orignal pinion shim for that axle. then ask him how much torque it takes to turn the pinion by itself with out the differential. it should be 25-30 inch pounds if you used new bearings. if he does not know what you are talking about then i say try another mechanic. there is a hundred ways you can install gears incorrectly and cause a humming noise. trust me i do it for a living. Posi's will not make any humming noise because there is no parts moving in it when you are driving straight exept the side bearings and these can be replaced separetly with out having to get the whole posi. they will only make noises when you are turning if they are worn out. what ever you do, dont drive on them to much or you will wear a incorrect pattern in them and the noise will never go away unless you buy another set.

Deeavi

iTrader: (16)

I just put a set of Richmond gears in my car. I set them up with .007 backlash. When I test drove the car the gears were whining pretty bad, so I went back in and rechecked my setup. I found that when I did a final torque on the bearing caps the backlash changed to .005. I changed it to .010 after final torque and the noise is barely noticeable now.

Setup is critical to proper operation of rear ends. That being said Richmond gears run a little noisier than some others, because of the nickle content in the gears. If I change gears again for the street I will use another brand.

Take it back the person who set up the rear! Good luck!

pjb

iTrader: (2)

I had a passanger side axle bearing (outer) cause a lot of humming. it sounds like snow tires or monster truck tires going down the road. when I pulled the axle the shaft showed some wear so I installed a bearing that had a spacer to make it ride on a different place on the axle shaft. it worked but now, a year later, I have the same noise coming from the driver side and it looks like the seal on the passanger side may be leaking. Tomorrow I am going to replace bearings, seals and axle shafts on both sides. I have loaner tools from autozone for removing and installing the bearings. Mobil 1 synthetic gear oil, GM limited slip additive, Felpro rear cover gasket and all should be quiet again. I just hope that I don't have trouble removing the ABS/traction control rings from the old axles and installing them on the new ones (I haven't done that part before). I'll let you know how it goes and the results.

pjb

iTrader: (2)

Everything went great with my axle and bearing swap (no problem removing/installing the ABS rings) until I went for a test drive. I have a real bad squeak from the drivers side. It appears that the new (actually used) axle has a bent flange (where the lug studs are) and now the rotor doesn't track correctly through the caliper. The place where I got the axles from say they will have a new axle for me today. The big pain is the fluid drain/replacement and resealing the rear end cover. I almost never use used parts on any of my cars or motorcycles, maybe this is why. $50 for a pair of axles sure sounded like a better deal then cost of new ones. Once this issue is resolved I'll report back on the original problem (humming noise).

pjb

iTrader: (2)

the guys where I got the axles from gave me 2 new ones. I put one in the drivers side, along with a new seal. I pulled the wheel and brake caliper and rotor from the passenger side, just to check if that axle was bent. It was ok. After all this, all problems are now gone and I am gliding down the road with no humming or noises (if you can call the loudmouth "no noises"). I love the sound of the loud mouth, but for a daily driver it can be a bit loud at times. Funny considering the open pipes on my Harley or my Texas Chopper NEVER bother me. Oh... the original problem with the humming noise from the rear was Axle shafts that had quite a bit of pitting on the outer bearing surface. It seems to me the wear would be pretty uniform all the way around the bearing surface, but these are pitted randomly around the bearing surface.