We have a 99 ford 250 plow truck. Here recently it was making a awful grinding noise in the front end. Almost sounded like the gears weren't catching in the diff. We replaced the steering stabilizer upper and lower ball joints both sides, u joints on both sides and on the front drive shaft and put new hubs on it. Still making the noise. I think I pin pointed it to the passenger u joint is hitting on the lower ball joint. Could this be caused by leaf spring being bad. Ours are starting to bend the other way.

Thanks.

 

Lets take a look at this from another angle.
The dimension between the u-joint and the universal for the end at the wheel should not be affected by what ever the leaf spring does. Something has changed, among which could be the spindle may be bent, the axle where the u-joint is attached is bent or possibly incorrect parts.There are grease fittings on some aftermarket ball joints and if I recall correctly the lower joint fitting is on the top of the lower joint . It is a close fit, but usually enough room for both. Can you verify that there is enough room so the u-joint doesn't hit the fitting? If the wheel bearing is not right the other half of the joint may be wobbling around.

 

I agree with Hanky, I am going to subscribe for future posts in case my assistance is needed.

 

I have taken it apart about 4 times now and can't figure it out. Is there a seal or a bearing that goes where the axle shaft enters the axle housing. I know there is the vacuum, but is there another one?

 

Like Hanky mentioned, some joints will make contact with ball joint grease fitting. In those cases you would grease the zert , remove, and install a low profile grease plug. OE ball joints didn't have grease fittings.

The axle tube itself doesn't have a outer seal, their is a dust seal that presses onto the axle shaft flange and runs against the axle tube face that keeps debris, water, mud, out of the axle tubes. Usually noticed tumbling around the axle, liked to split and fail.. When you had it apart, what condition was the larger (black) nylon thrust washer in? After setting the axles large seal in the spindle bore, bearing assembly installed,, snap ring, small thrust, spacer and snap ring was installed against the bearing carrier?