vasinvictor

iTrader: (3)

Should this rear axle bearing have play in it? Watch it in blurry 1080p if you choose Could this be the source of a cyclic humming vibration at highway speed? http://www.youtube.com/watch?v=tSKQAxxn_oM

vasinvictor

iTrader: (3)

I just pulled the axle shaft out of my 94 4Runner also. It has the same play in it, maybe a little less, but still there.

TNRabbit

Could be. Have you check the mating of the diff gear surfaces?

dubbsbetty

iTrader: (2)

I would say that could definitely be the reason to the humming vibration your getting at highway speeds. Those bearings should be press fitted with no movement available, also if you have rear abs, there are two bearings per shaft I believe. I know it sounds stupid but check your tire pressures too, if one or more tires are uneven it can cause a rattle-like vibration/sound at certain speeds.

vasinvictor

iTrader: (3)

Can you give me an idea of what I should be looking for? I've looked at them, but I don't really know what I'm looking for. I know one diff has more backlash (I think that's the correct term) than the other. One kinda makes a metallic clunk when turning the pinion flange back and forth, and the other one, more of a soft click.

rlordjr

I just pulled and replaced my left rear wheel bearing. I had a clunking noise going over small bumps, but not sure that was the cause. The bearing was shot and had the back and forth movement as well. It shouldn't move that way at all. If it does the little balls inside are all worn down or the races are worn and that's not ever good in a ball bearing.

vasinvictor

iTrader: (3)

Just took it the best mechanic I know and he said indeed bearing on both sides are shot and he should have new ones pressed in by the morning. He also remembered when I used to have Cadillac cars and teased me a little for it I'll report back when I get my "new to me" 3rd member stuck in and my axle shaft with new bearings.

vasinvictor

iTrader: (3)

Just to update yall. After having new rear bearings pressed in, the original ones didn't look bad at all. Also, brand new bearings still have a tiny amount of play in them. You can still move that drum backing plate in relation to the axle. Anyway, vibration not fixed. $350 down the drain- lesson learned.

vetteman

VASINVICTOR - Did you figure out the cause of your cyclic vibration? My '93 runner has a vibration right around 60-70mph that occurs once every second or so. Not sure how else to describe it. Just rebuilt the whole IFS... new bearings, cv shafts, bushings, seals - no dice... had the tires balanced too.

vasinvictor

iTrader: (3)

I can tell you that I replaced almost every piece on that truck, except for the transmission/transfer case and never did shake those vibes. I had new rear driveshaft built, front end replaced, tires balanced, wheels bearings, axle bearing, etc etc. I still think about it from time to time and I wonder if maybe my front ADD wasn't working and staying locked in, thus causing the front driveshaft to spin all the time. I never did check the front driveshaft for bad ujoints or proper balance. If you jack up the front end and turn front tires, and see if the front driveshaft turns too. If it does, then the ADD is not properly disengaging and perhaps that's causing a vibration. Other than that, you should check to see if you ujoints are in the same phase, your pinion angle isn't off badly (caused by lifting or lowering), or worn out motor mounts/transmission/transfercase mounts that are causing metal on metal. Also, remove one driveshaft at a time and see if it gets better with either of them removed. I wish you better luck than me.