hey guys i have a weird kinda question. I just upgraded my rear end on my 1990 firebird its a v6 currently ( getting it ready for my 350 swap ) i just installed a 3.27 discbreak posi rear end ( came out of an 88 GTA ). i didnt change the proportinating valve because its a 1990 and i think its the same ( i originally had drums ). i bled the breaks until the pedal was tight and strong. now that i have been driving it for a little while, with new pads and rotors, it makes this weird moaning noise when im going really slow and i tap the brakes to start to stop. it does stop but it keeps making that weird noise. and its only when im going slow. if im going fast and stop it dosnt make that nose only when going slow. it also sounds like its coming from the passanger side rear. please please please help me out.

 

can anyone help

 

are you sure its not the rear end moaning?

 

My rear end moans with my Baer kit, but only when I'm going in reverse. I've the proportioning valve turned all the way towards the rear indicator and I still don't lock up.

 

im pretty sure cause it only sounds like its coming form the passanger side. if however it is the rear end what is it the problem the diff. or the whole assembley

 

differential pinion angle. now if your rear is out it will make noise. gears worn or harder gears make noise too.

 

how do i change the pinion angle. if the rear is out what in the inside do i have to replace all of it or just a few pieces and would i have to pull it again?

 

adjustable torque arm will adjustpinion angle. Is your car lowered? If the rear end was ever apart and someone set the gears up in the housing incorrectly it will have to be pulled apart and shimmed correctly.

 

my car is stock height i plan to lower it after i do dual exhaust and i swap in my 350 motor. i dont know if the rear was ever played with cause i got it out of a junked 88 GTA (got the motor out of the same car). is it possible to re adjust the rear with out taking the whole axel out of my car. also who makes a good adjustable torque arm that is possibly my problem cause i have a V6 and i use the same torque arm and i had a HELL of a time getting it back on the axel. if it is the diff what else do i have to buy (ill probably go with aftermarket stuff) its a stock 3.27 rear axel the rare one and i believe if i can remember it is a 9 bolt. btw thank you for all your information

 

I have the Eibach Pro-kit, Tokico HP shocks, Spohn LCAs w/ relocation brackets and panhard bar. My rear was rebuilt with a Torsen posi and 3.23 gears added. I am running the stock torque arm. Could this be my problem with my rear brakes moaning while going in reverse?

 

It sounds like it's doing the exact same thing the rear end out of my '87 GTA did. It sat for three years before I parted it into my Firebird, and when I got it together, it would groan like that. hitting the brakes would stop the groaning, and it would stop after hitting about 30 MPH, but it still sounded like something was rubbing. It turned out to be the differential cones in the posi unit. I'm currently trying to find a diff right now. If that turns out to be the case for you, then I pity you. 9 bolt parts are hard as hell to find.

 

No, No, No everybody. Its the brake pad compound that is causing the low speed moans.

ssj, Try and taper the leading pad edge with a grinding wheel. If that does not reduce of eliminate it then go to a softer pad compound.

 

hmm that sounds interesting i will have to try that when i get a chance to do that. and i hope that fixes it casue i really dont want to fix the rear end cause it seems to work well and i got a TON of torque out of it ( for a v6 )

 

I also have a V6- very custom, but still a V6. It is the very reason that I will never have real raw HP on this car is why I decided to retain a factory 10bolt rearend and modify it with better axles, bearings, gears, and locker. I do not think I could ever break in- this car was designed for strictly a daily driver and not a high HP racecar (I have others for that purpose).

What pads are you using? Might I guess they are Performance Frictions?

 

i dont remember what type of pads are on the car i got them for advance auto parts and they were the cheapiest they had cause it was all they had. im not sure of the name i know its ceramic pads thats all i can remember. can anyone recommend any good ones for me to go get or should i just try grind them down

 

If you want a very good pad that will give you GREAT performance levels and not one bit of noise trouble then I have always and still do highly recommend Stillen MetalMatrix pads. I have used them for years on several of my vehicles including my Camaro.

I do not currently run them ONLY because they do not offer a pad to fit my custom Wilwwood application. I to this day am still having trouble finding a brake pad that is a decent all around pad- EBC greens are so far the best I have tried for my Wilwood setup after trying 3 different wilwood coumpounds, 2 different EBC compounds, a Porterfield coumpound(currently on there making noise), a Hawk compound and a Ferodo compound. IF I COULD BRIBE STILLEN TO MAKE A SET FOR MY WILWOOD I WOULD HAVE THEM ON THE CAR RIGHT NOW-I tried to bribe them, they will not do a special run for me even though I offered the backing plate.

I had tried EBC greens on my old factory brake caliper setup and they were the closest thing to Stillen however EBC pads leave a pad buildup on the rotor when they reach higher racing temps, and then they do fade. This pad build up leaves the pulse feeling in the brake pedal from uneven surface. Stillens never did this on any of my vehicles and they are very very hard to fade unless on a high speed road course. I thought I had possibly discovered that the Stillen pads were a R4-S compound and hence I tried going to Porterfeild for theirs- not even close, I was wrong. The porterfeild actually felt promising when I was bedding them, but once the conditioned the rotors enough they began to moan and there was a lapse in initial bit when low temps and you have to press a bit harder then the grab a bit to hard making it uncomfortable to drive in daily traffic.

 

That's what I thought mine were coming from at first as well. It acted exactly the way that's being described. It turned out to be one of the friction cones in the posi carrier that was worn out, and rubbing against the carrier.

I hope it's just your brakes, but if the brakes turn out to be good, I'll bet dollars to donuts that it's the posi cones.