Hot Rod Forum banner

Differential noise after warming up?

5K views 3 replies 2 participants last post by  frankenvette 
#1 ·
Took a ride today in my Nova and after about 30 miles through back roads and small towns, the rear differential was making a grinding noise when starting out, maybe the first 10-15 feet, then quieting. I pulled off the road and checked the brakes and differential for heat. The right brake plate seemed a little hot, could keep my fingers on it for about 5-6 seconds, left was a little cooler. The axles were slightly warm to the touch, but the differential was very warm. Couldn't keep my fingers on for more than a couple seconds. Having never touched these parts before, I don't know if this is excessive heat or not?

When I got home and the car cooled, I pulled the right rear wheel and checked the brake pad adjustment, and they were off as I just installed new pads a few weeks ago. I checked the fluid level in the differential and oil dripped slowly when I removed the plug, so I would assume the fluid level is fine. What else should I look for, or what other checks can I make?

As usual, all assistance is greatly appreciated.

Thought this may help, the rear gears are 4.11's and my average speed was in the 50-55mph range, making 2,500 - 2,700 rpm's.
 
#2 ·
Brakes dragging! The rear drum brakes were serverly out of adjustment, heating up. The parking brake has been removed from this car and I am wondering if the auto-adjusters are functioning properly, and if I can run without the auto-adjusters? I have Wilwood front discs.
 
#3 ·
One thing that I can contribute, not sure of how much use it will be to you, but when I had some chatter in my posi unit a few years back, all it took was some GM differential additive to quiet things down. It's a cheap solution so I always try that first when I get noise in the rear end that sounds like it could be simply due to friction.

good luck

tbw
 
#4 ·
blndweasel, forgot to mention, my pinion seal has a slight leak, but the fluid level was fine. Anyway, I got the addditive and new diff lube and plan on replacing when I change my pinion seal. Any tips on changing the piniion would be GREATLY appreciated!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top