Wheel wobble

[WoodenBirdOfPrey]

I'm still working on Virginia, AKA project "more wrong than I thought".

At speeds above 60-65mph it develops a shake.  It doesn't feel like the front end, as the wheel stays still and calm, the whole car tends to shake so I started looking towards the back axle.

If I put the rear up on a jack and put the car in gear both rear wheels seem to wobble side to side about a quarter inch out at the tread.  The tires are BFG All terrains, purchased new and balanced less than 1,000 miles ago, and my memory is fuzzy but I think the shake was present since I bought the car with the old tires on it. 

I just swapped the front and rear wheel on the passenger side and tried the same test again.  Same result, I'm getting a very noticable side to side wobble.  I'm pretty sure it isn't bent wheels because it seems highly unlikely that 3 wheels are all bent the same amount ( I haven't tried the front driver's side yet )

So what may I be looking at here?  My mind goes straight to the axle shafts, as the early models were known for weakness, even though this was caused by human error during installation.  I have no idea how to check that theory though.

Any help will be greatly appreciated.  Thanks in advance!

[WoodenBirdOfPrey]

Additionally, the car has the 5 spoke steel XJ/YJ wheels on it.  It doesn't look like there should be any clearance issues with the little bolts that hold the brake drums on, and I never heard of anyone else having this issue, but that still doesn't rule out the possibility.  I may have to drag one of the factory alloys from the parts car down to the garage and see if I have the same wobble.

[Prafeston]

Did you try running it without the wheels mounted? See if the hub is also wobbling?

[WoodenBirdOfPrey]

No, I don't know if the wobble would be noticeable or not, especially since the drums aren't the smoothest surfaces.

[carnuck]

Got any spare wheels to put on and see? Could be a twisted (about to break) axle. '80-82 had an issue with the RH side being overtightened from the factory by accident.

[WoodenBirdOfPrey]

I do have spare wheels on the parts car.  I don't think it's likely that this is the same issue as the early years had with being overtightened, as it's an 87 and it's both sides.  I guess it's possible that somewhere down the line somebody has replaced the axle shafts with older ones, or even overtightened the original ones.  It just seems really unlikely to me that something is bent or damaged equally on both sides of the rear end, I'm hoping it's something along the lines of a wheel fitment issue or improper assembly.

[Jurjen]

Do you still have the three little retainer bolts in the drums?
They don't go together with the Cherokee Sport rims, so either remove them or replace them with counter sunk screws (like I did).

[WoodenBirdOfPrey]

Do you still have the three little retainer bolts in the drums?
They don't go together with the Cherokee Sport rims, so either remove them or replace them with counter sunk screws (like I did).

Bingo!   The retainer bolts are still on the drums.   I considered those as being the issue,  but it looked like there was enough clearance to me and I never heard of anyone having that issue.   I'll take the retainer bolts off when I get home and report back.   Thanks!

[Jurjen]

Here's a picture of what I did (counter sunk screws).

[WoodenBirdOfPrey]

I removed the retaining bolts, that definitely helped.  The car still tends to shake at 70mph and over, but not as bad now.  I'm going to start by replacing the worn pitman arm and getting the front end aligned, then continue troubleshooting from there if I still have shaking.

Those retaining bolts must not be all that crucial, I noticed the replacement drums I ordered (and didn't need) don't even have the holes drilled in them.

[txjeeptx]

The lil bolts aren't necessary once the wheel is bolted in place. They're there to help center the brake drum and keep it retained whenever the wheel is not bolted on, but they serve no real purpose if the lug holes in the drums fit closely to the studs in the axle hub. Their only real purpose in life is to confound the next mechanic who has to take a look at the brakes once they're well rusted into place.

Hopefully the steel wheels you have aren't too bent. They don't run all that true from the factory, so some wobble should be noticeable when spinnin em around. The tire shop coud try breakin the bead away from the rim and rotating the tire to find a better balance and/or less wobble.

When you go about aligning the thing, make sure the rear axle is square in the car - they can get outta line and cause weird alignment problems if a rear leaf spring pin has sheared or if one leaf pack was replaced with one that doesn't match the other's dimensions exactly.

[carnuck]

Those bolts main purpose was to keep the drums from falling off/getting offcenter during wheel install on the assembly line.

[WoodenBirdOfPrey]

I think getting the 5 slot alloys on my parts car powder coated and swapping the tires over will be higher up on my to-do list now,  knowing that the steel wheels probably aren't real true even from the factory.  I'd like these tires to last more than a couple years.  Looking at the PO's maintenance log,  seems like he was replacing them every 12,000 miles.

[WoodenBirdOfPrey]

No mistake.  As bad as the wheels were wobbling on the back, I know that had something to do with it, and the strut rod bushings,  we'll,  there wasn't much left of them.  I intend to put XJ leaf springs and new bushings on the back too,  although the how-to on here is kind of open ended about where I would get shackles or bushings that are compatible.