I have a pretty bad vibration coming from the passenger rear wheel over 45 mph. My buddy was following me and said it looked like my wheel was bent. Took it to the tire shop and they checked it and said it's not bent, balanced and sent me home. I pointed my mirror at it for the drive home and see some pretty bad side wobble. Could my axle be bent?

 

Yes..

I know the tire shopped balanced the tire but I would swap tires side to side as another way to eliminate a bent axle. If it changes to the other side you know it is the rim and not the axle..cheaper and easier to replaced a rim.
other possibility is a rear bearing going out and causing a wobble due to free play..

 

Just swapped the wheels and confirmed it's the axle. Next step is to confirm whether my axle is first or second gen. Need to figure out the length of my housing, where to measure and such. I have spacers up front and my tires stick out evenly front and rear which makes me think I have a wider rear axle, just need to know how to tell.

 

Got my new inner shafts. Now question is, do I need to drain the diff to swap them? I realize this is technically the wrong area, but I figured why start a new thread somewhere else if this is already part of my original question. Thanks for your help.

 

You don't really need to drain the rear diff to remove the axle. It will dribble a little, but nothing major. The biggest problem with fluids is the brake line making a mess. You're also going to have some fun getting the axle free from the backing plate.

 

It's not a bad idea to drain the fluid, but its nota requirement. If you jack up one side (replace one axle at a time) the fluid will drain to the other side so that will keep fluid loss at a minimum.

If I knew my fluid was fairly new (10k miles or less), I would do it this way.

If fluid was questionable, drain it, do your axles, fill it up with fresh 75W-90.

 

Thanks. I'll just drain it and start fresh. Can't hurt.

 

I was lucky enough to grab an axle, drum to drum for $100, so I can skip messing with the brake shoes and such for now. I'd go the easy route and swap in the axle, but mines loaded with 5.29s and I can't mess with gears. But, I can use this spare housing to prep for disc brakes and all the beefed up axles, Detroit locker, then pay someone to load my gears and swap in the fresh one.

 

No need to "mess with gears" when swapping axle shafts or housings. To swap axle shafts, just unbolt and remove the old one, slide in the new one. And for a housing swap, just unbolt the 3rd member, and move it to the new housing.

To determine bent axle or wheel, easy check is to put the rear end up on jack stands, block the front wheels. Then pop into 1st gear with the engine idling. Use a pointer of sorts to hold up against the wheel and tire as it spins. If you see runout on the tire surface, check at the wheel surface. In none seen there, tire is out of round. If runout at the wheel, then remove the wheel from the axle and put the pointer against the brake drum and check for runout. If runout visible there, bent axle shaft, otherwise bent or uncentered wheel (might be a hub-centric vs. lug-centric issue). I have had more bent axle shafts than I can remember, at least until I switched to a full floating rear axle, now the truck rides so smooth on the road.

 

Had no idea swapping housing was so simple. It definitely was the inner shaft and that was a twenty minute fix. So now I have a spare housing I'm going to clean up and build proper with discs and a locker (current setup is welded) It's a paycheck to paycheck deal ya know.

 

It takes the a good half a day to swap a housing over, but nothing hard to do. Depends a lot on how complete the new housing is and what all you need to transfer over. Things like the brake hard lines and the e-brake hardware, axle seals, breathers, shock mounts, etc. all take a bit of time to transfer or install. I think it took me a good 2-3 days to swap mine as I had to deal with running brake lines to the new calipers, hooking up different e-brake hardware, etc.:
- http://www.4crawler.com/4x4/CheapTri...shtml#RearAxle