Gears & Axles - How bad are these bearing surfaces?
04-22-2012, 05:55 AM
I'm chasing rearend noise and intermittent significant heat in the rotors (not the calipers, though). The noise doesn't come/go with speed, but with time - the longer I drive it (per trip), the noisier it gets. I believe the correct statement would be that it gets noisier with HEAT. It starts out dull and eventually gets to the whining pitch of a prop plane in a nose dive.
I'm struggling with a suspension bind back there and I believe they're all related (bind, heat, noise, my lack of sleep).
The question for today is, are the axle surfaces below "that bad"? I know they could probably be replaced, but they're not bad enough to cause significant noise and heat, right?
04-22-2012, 07:28 AM
Quote: intermittent significant heat in the rotors
Sounds like a brake problem. To affect both sides a collapsed hose
at the differential is a possibility. Rubber brake hoses can be
intermitent as you describe.
axles look to be normal.
04-22-2012, 07:34 AM
Compared to what I've seen over the years,those surfaces seem 'new'.
these I polished and still running
I would consider this beyond serviceable
04-22-2012, 07:43 AM
Those axles are not your problems. The pass one is starting to show some pitting though. I would probably just change that axle bearing and both seals. The noise ,grab pinion yoke and see if can be moved up and down at all. Should not even a little. On road test get noise going then go on and off gas easy. Pich change usually indicates pinion bearings. If continuos grind in middle of pumkin suspect carrier bearing. Best I can describe without actually hearing.
04-22-2012, 08:00 AM
Thanx guys. I did notice the pitting starting on the pass side, and I thought the surfaces looked fine, but I read a thread somewhere a while back that suggested once they dull over they're done.
I went to the brakes first, and did find the sliders to be gummed up, so I took it all apart and cleaned/greased everything. Same problem, so I went extreme and removed the caliper, wired a 2x4 into and secured it to the axle, I also removed the parking brake shoe (so now there were no rear brakes). I still got the heat and noise, which starts once I feel the rear suspension start to stiffen up, about 2-3 miles into my commute.
I'm sure it's the bind that's causing it all, I was just hoping that I hadn't already damaged the axles. I'm not sure the best way to check for a bent tube, since there is so much crap on the tubes I cant find a good place for a straightedge. That's what I'm working on this morning.
04-22-2012, 08:09 AM
Forgot to add:
No movement in the pinion, no measurable slack when wiggling in a rotation (is that what's referred to as backlash?). All seems nice and clean and neither tight nor loose.
With the axles out, I can spin the pinion as fast as I want and everything is whisper quiet. I put the axles in and as long as the are both spinning, still barely a sound. If I stop one, I can hear the typical torsen chatter, but nothing real significant. Pretty much the same if I spin the axles instead of the pinion. It does get noisier with the weight of the wheels, but not that bad.
If I put the rearend up on my lift boxes and run it at 35 mph for 10 mins, no heat. Run it up and down between 45-75 for a while, no heat. It's only there when there's an actual load. When it starts, I can hear what sounds like a tire being drug slightly sideways.
Next I'll find a way to attach a straightedge to the rotors and run it a few feet out to see if there's any toe.
04-22-2012, 10:54 AM
No relevant toe. The pic shows how I measured it. I then stood the rearend so the pinion was straight up and took the same measurements, with nearly the same results. It came out slightly wider when I did it that way (about 1/8"), which I would attribute to camber (wider at the bottom).
That's the best I could come up with the check if the tubes were straight.