So I just got my magnecor wires in the mail and will be installing them this weekend. But that isn't what this is about.

I have a vibration that comes on at about 70 mph or so. It is probably there at slower speeds but not enough to where I really feel it. I have done some reading on the forum and know that I need to change my drive shaft u-joints, especially the two on the rear of the front drive shaft. My question relates to this.

When I bought the Disco I noticed that all 5 tires (including the spare) were slightly scalloped. I was told that this was an alignment issue and that it had been fixed. I always contributed the vibration to this and since the tire scalloping problem never worsened, I thought a new set of tires would solve the problem. But the tires have lots of tread on them and don't want to buy a new set if this problem still persists. So do bad u-joints cause scalloping of the tires? I will still be changing the u-joints to greasable ones since everyone of you recommends it, but I'm not sure if this would cause the tire problem. Since the spare is slightly scalloped also I can't say if the problem comes from the front, rear, or both axles.

Any thoughts? Many thanks

 

Just install your magnecor's and you'll be fine.

 

Just kidding - I'm no expert, but I doubt that the driveshaft would cause tire wear (although if it can cause the steering wheelto shimmey, why not the tires?). I would replace the ujoints, make sure your tires are aired up properly and rotate them often. If the vibration / shimmy is that bad and the tires still have decent tread on them, I might get them rebalanced and the front end aligned again to be sure.

 

Yep, I plan on doing that. I am curious what other members have noticed with their tires when also noticing vibrations at speed.

Any others?

 

I had some vibrations after 75, they went away after u-joint replacement. When you say scalloped, are they getting worn heavier in the center? That's usually tire over-inflation. Do you inflate to the spec that is in your manual or printed on your door frame?

 

Nah, by scalloped I mean that all around the edges on the inner tire it is worn every two inches or so. Imagine a pie crust that is lumpy all around the edge. To a much smaller degree that is what the inner side of all my tires look like. It isn't much, just slightly worn. This will cause vibrations I know but since all five tires are this way I can't localize the problem. That is why I am curious if u-joints are the cause, to me it seems like front end alignment or tie-rod/bearing/stabilizer anything else in the front end. I'd really like to know if anyone with bad u-joints noticed anything with their tires.

I can't understand why the previous owner would have just rotated the back tires to the front when the fronts were scallloped.

 

What brand of tires are on your truck, and are they 16 or 18"??
Get that front drive shaft rebuilt before you land up buying a new tranny, which you will when the u-joints fail.

 

I've got a set of Goodyear Wrangler HPs on 18" rims. Tires are 255/55 R18s. I know I'll get that front shaft rebuilt. One of the things on my list before I start driving it again.

So Mike has it been your experience that the front drive-shaft/u-joint problems have caused scalloped or uneven tire wear? If this is common to the problem then great! If not then I'm sure I have another problem lurking under the car.

Thanks

 

Sounds to me as though your tires are what's commonly referred to as "chopped".
The most common cause of this is lack of timely tire rotation.
dk

 

thanks doug

So is it typical then for D2s, or any 4 wheel drive to develop "chopped" tread if tires haven't been rotated? If so what is the main cause? I know that varying amounts of torque over time can cause uneven tire wear but all the tires seem to have the wear in the same place and manner.

Thanks again guys keep it coming.