Hi people I am after some advice. I just put in a reconditioned LSD centre with 3.55 gears in my 8 inch diff. The gears are auburn. I am noticing a diff noise on acceleration between 40-50 miles an hour. I only drove the car four about 10 miles after the install from the work shop and the noise seemed to ease. I haven't driven it since due to work and weather. I am wondering if the noise is just gears and lubrication settling in or does that mean the centre wasn't shimmed or regeared right.

 

if they are dead on they can whine.... My 380 wines a bit in coast but not under power.

They may quite down after a bit but I doubt it. Its probably just because the ring and pinion weren't perfectly matched during install. If its just barely noticeable you should be okay.

If you can feel the sound or hear it over the radio...that might be a different story.

-Gun

 

OKay, changed the oil to a heavier weight of 140 and it quitened it down a little. Drove it this weekend for about 300 miles and when coasting no noise, under slight throttle between 50-63 miles noise. Thinking back I had a little noise after fitting the Heidts four link, it wasn't there prior to the four link. It got worse when I changed it from 2.79 to 3.55 gears. When I took the diff back to the diff builder he said the drive shaft was at a bad angle. I am thinking that maybe the diff angle needs to be changed to set the angle correct and this could be causing the noise. Any opinions?

 

Pinion angle should be checked immediately, I'm surprised no one brought this up. Anytime you alter the makeup of the rear, the pinion angle should be checked. If the pinion is not exactly parallel to the engine/trans angle, you'll get stress, and gear whine is only the beginning. You can get pinion wedges from and speed supplier.