I just picked up a dana 30 out of a TJ over the weekend. The guy selling it said the tj was hit in the back. I saw that the lower control arm mounts wear bent before i bought it. After breaking down the axle i'm noticing that the two upper ball joint mounts are not lined up with one another. Are they supposed to be perfectly center down the axle or is there a offset. I put a tape measure from ball joint to ball joint and it is not center. I also flipped the axle over and checked from center of lower ball joint to the other side and it is center. So it seems just the top is offset. Is there any other way to check if my axle tube is bent?

Thanks, Mike.




Passenger side



Driver side not really that bad



Upper ball joints are not center

 

Not sure the tape measure gives you an accurate answer.

 

Are you going to cut out the bent control arm mounts and install new ones? If so, you better make sure the tubes are not bent before doing all that work.

 

You can just tell by looking at it that the ball joints are not center. I don't know is this is how their supposed to be, thats why i am asking.

And yes i plan on cutting and rewelding in new lower mounts

 

Set up the jackstands so both sit at the same height. Lay the axle over them and take some measurements. Rotate the axle and take a couple more measurements. Without a shop that can check it for you, thats all i can think of. Never tried it myself, tho.

I wouldnt rule out an axle tube that rotated a little, along with being bent, as another possibility.

 

What exactly should i measure?

 

From the ground to the tubes, and other points. A straight edge will come in handy, too. A carpenters square, for example.

 

I guess you need to find two common center points and use those to run a long, straight rule side to side, and then see i how the big C's relate to that ruler. They should be the same, no offset, otherwise wheel alignment would be off.

I guess you could also measure the sway bar links to the floor - should be the same when the axle housing is on jack stands the same height.

 

Don't ya hate threads where you don't know if there was a happy ending?

 

My best advise is to take it to a driveline shop and have them check it. You can also set it on blocks over a hard floor and using a level, set it so the spring perches are level with the floor. Then using a carpenters square set on the floor, measure the angle of the ball joint axis on both sides. The caster angle is built in by the ball joint axis being 7* from vertical. Whatever you find, they should be the same on both sides. The camber angle is also built in, but that can be adjusted with offset ball joints to a certain extent. Both caster and camber angles can be adjusted up to 1.5* with offset ball joints.

Caster is the vertical angle the ball joints are set at front to rear so the wheels try to return to center by themselves. Camber is the angle the wheels are from vertical to keep them from tucking under when cornering. On vehicles with independent front suspension, camber changes as the suspension compresses. Solid axles don't, except for when the whole axle flexes.

 

My best advice is to not drag up old threads.

 

Yeah, they do that all the time and too often we don't catch it.