vanillagorilla

iTrader: (1)

I've been having a bad vibration at certain speeds, and just started last week. I was a new stretch of freeway here that is perfectly smooth and I found that my rear end started hopping at about 54-56mph. I adjusted my mirror to see the rear tire and sure enough it wobbled a bit.

I threw it up on jack stands and ran it and it was obvious the wheel was wobbling. All lug nuts were tight and good to go. I pulled the wheel off and ran just the rotor with the lug nuts tight against it. The rotor had a significant wobble to it too.

So I pulled the rotor off and by that point it was hard to tell if it was wobbling. I put a dial indicator perpindicular to the axle flange and got about .005 of runout. I got .010 at the end of the rotor. I didn't check the runout at the wheel since I didn't want to scratch them and I'm sure it's worse. The axle bearings have no radial play and they have about 40K miles on them. The rotor is still the original too.

How much runout should I be looking for, and how in the hell did I bend the axle If that's even what the problem is?

Toaders

Did you crash the truck or anything? I bent my axle and it was because i hit a curb around 20MPH sliding sideways. it takes quite a bit of force to bend an axle.

vanillagorilla

iTrader: (1)

Lol...no wrecks or curbs or anything. I avoid potholes like crazy too. I don't think I could jump a curb if I tried with how low and long it is. It was sitting for about 2 weeks, then I drove it to Ace hardware and that's when I noticed it. I took it to work last friday just to confirm what speeds it did it at. It smooths out around +65mph.

budhayes3

iTrader: (19)

Not sure on the runout spec, but if you can visually see it the way you're describing I'll bet that it's out of spec. We have an 08 GX on a lift right now with a bent L/R axle that's causing a squeak when braking...the rotor is rubbing against the backing plate...

454navyss

iTrader: (46)

if you can see the rotor wobbling when its on jack stands and a dial indicator says its bent i'd change out that axle

vanillagorilla

iTrader: (1)

Yeah, I have no problem changing out the axle or rotor, but I guess I'm more concerned with how this happended. If I put a new one in, will it do it again? Could a bent housing cause the axle to bend/warp?

I can't see how an axle could fatigue after 90K street miles.

Edit: Here's a quick video of the flange doing its thing. It appears its just the flange surface that got bent. Total runout of .010.

On20Z

iTrader: (3)

You my friend have just answered my headache with the rear end.Dou you notice at all when you are goin at about 50-60 the let off.My bed bounces like crazy.My axle does the same thing with new wheels,shocks,etc..Let me know how you make out.I still need to get someone to check runout for me as i dont have a tool.

budhayes3

iTrader: (19)

I just did some digging in my 99 service manual, and found the spec for "wheel hub" runout, it didn't specify front or rear so I'm assuming that the spec is the same in all 4 corners. (it's in the same spot of the manual that tire and wheel runout, as well as propeller shaft and pinion runout can be found)

Max runout is .0052

2005 Silverado

iTrader: (19)

I get what you described at 75, but it goes away around 90, then i have a driveshaft vibration (its only balanced to 3300 rpm, and that is a fuggin nightmare haha) I think i need to check my axle now.

I hate vibrations...they can go to hell!

Dustni

budhayes3

iTrader: (19)

Vibrations are cool when there's a lady in the passenger's seat who's not wearing a bra....besides that they suck!