Old Gears Old Noise, New Gears New Noise

[rbreith]

So I had some rear end noise so I decided to tear it apart and re gear the rear end.
I changed:
U joints
Rear wheel bearings
New gears new bearings to go with the new gears
New dif cover
New upper control arms
New Lower control arms
New lowering springs
New brake fluid
Torque box reinforcements (welded in)
New wheel cylinder passenger side (for brakes)

So while I was re gearing the rear end I followed directions and everything was within tolerance. I soaked the clutch packs in oil, then in oil and friction modifier.

It was fairly hard to read the gear tooth pattern but I felt it looked good. I did it about 5 times and had my wife look at it and tell me where she thought the teeth were impacting and we were on the same page.

Put the whole car back together took it for a drive yesterday seemed fine a lil noise.

Took it for a longer drive today, AND

has a whine seems to be from the drivers side (wheel bearing?)
goes away when I turn to the right (passenger) makes noise when I turn left (driver)
has a whine at about 20mph from the center
brakes sound like they are grinding and petal feels weak, but the car stops

lots of fun stuff with this car. I'm trying to get her so I can drive it but problem after problem.

Thanks in advance for your help.

 

[Mintsick]

Sounds like possibly a wheel bearing on the left side, what brand gears did you go with? Some brands are known to be louder than others.

 

[mikestang63]

• how much ger oil did you fill it with..
  
• did you take it easy for the first few hundred miles..
  
• does it make a noise when accelerating or decelerating.
  
• what brand gears did you use
• what tolerances did you end up with for backlash and preload
• are you sure the c clips were firmly seated

 

[rbreith]

I put about 3 bottles in I'm going to try and get another bottle today and get it in there. new dif cover so I'm not to sure how much to get in there.
I have probably put 2 miles on it since I did the gears. the harsh noise makes me not want to drive it.
I'm going to take it out again today and try to narrow down more how it makes the noise. but it was about 20MPH while accelerating.
used Ford Racing gears
I don't remember the tolerances but they were within spec as per ford racing directions.
c clips were seated and retainer pin slid in with no issues.

My plan is put another bottle of oil in and take her out again. if that does not fix the noises I'm going to drain the fluid and take the dif cover off and have a look. If it comes to that I can re check my tolerances and get you all those numbers.

I'm on "vacation" for another few days so I hope I can solve the issue or issues by then.

 

[mikestang63]

spec is 2 bottles of gear oil and the small bottle of friction modifier. I would be pulling the cover off and the axles out

 

[rbreith]

well I also had a sound from my right (passenger) rear brake and took that off and seems a spring broke and shredded the auto adjuster so need to get a new one of them guys. I'm drying out a big jug so that I can save the good gear oil that comes out when I drain the dif. ill pop the cover off and pull the axles and see if there are any issues.
Any clues on what to look for.

 

[RaggedGT]

How did the spider gears look?

 

[Moosee1955]

I'm no differential expert but consider myself a pretty good mechanic. I've owned 3 80's mustangs. The broken spring will keep the shoes from returning, and with the jammed up adjuster, you were running on 1 1/2 rear brakes. As to your gear noise, I'd pull cover inspect all clearances again. Did you replace rear bearings/ seals or did you reuse anything? Everything in the differential has got to be dead nuts! Proper oil/ friction modifiers. I'd use Ford oil/ additives. I also participate on the Ford expedition site, and see guys having noises with wrong oil/ additives. That being said, can you remove gears and clutches and have a second set of hands inspect your work. Again I'm not questioning your work, but sometimes we miss something. You've got a good chunk of cash invested, I'd like to see you fix this issue. As a rule never change just one wheel cylinder, always change in pairs, uneven braking if you do, not to mention other side starts leaking soon after. I'd put new axle bearings, a bearing that works ok coming out, acts up when you throw it back together. Weakest link theory.. Ford parts usually work best, but you could have gotten a bad fit. See if your dealer will warranty your gears. Like other reader said, inspect spiders, and all washers, shims, make sure nothing is amiss


Sent from my iPhone using Tapatalk

 

[rbreith]

so just pulled the rear end apart, backlash was not good. so I changed it. its now at .010 within the .008-.0012 spec as per FRPP manual. the pinion preload is at 26 in lbs within the 16-28 in lbs spec as per FRPP manual.

Thanks for the info on the wheel cylinder makes since to me should probably replace the other one.(driver)

The wheel bearings are new have probably 20 miles on them. Did them because they were bad then on the way to work I had the weird "old noise" which was from my upper control arm bushing failing.

The whole install of the ring and pinion were done with FRPP, New bearings and races all around even though the old ones seemed fine to me. Spider gears look good to me, there are no chips, burs, or any heat marks on them. Clutches were soaked in FRPP friction modifier and I am using Royal Purple 75-90 oil to help the gears brake in.

Drivers axle has some pitting due to a bad bearing (fixed when I bought it) and after I fixed it the noise went away.

I would love to have someone check my work but I do not really have the time to do it now. This gear (and control arm) install has takin me over a week and I'm running out of "vacation" time.

thank you guys for your help. Taking the dif cover off was my last step and I'm glad I just jumped to it and seen that the backlash was off.