Just brought a boat 1100 miles on a tandom trailer(2001 loadmaster). The two front tires seem to be bowing to the outside, the tire wear on the one is half a bald tire and half good tread. There must be a 1/4 inch difference between the bald and tread on the tire. Whats wearing,worn or needs replaced?Would the bearings cause this? Have no info on the trailer history. It does have the most grease slung all over the wheel then the others. The other 3 are clean other then road grime.

Bearings would be a good place to start, grease every where would indicate a problem with them. Might want to check on that sooner rather than later, some designs will allow the rim to come totally off once the inner race is destroyed.

could be the foward axel is bent from highsiding. as for the excess grease, I see that mainly from someone over greasing the bearing and when you go highway speed it gets to its normal operating temp and shoots the excess out on the wheel. Wipe off the wheel and after some more towing keep an eye on it. If a bearing was bad with the miles you already traveled you would already be sitting on the side of the road cursing it out. Now that you are home with it if you have some extra time just pull the wheels and check the bearings, not a hard job, just dirty and time comsuming. good luck.

2 things to consider:

If bias ply (non radial tires) the wear could be casued by sway (trailer swaying back/forth due to weight distribution issues like boat too far back or tongue too high)

Check to see if axle is bent, try measuring on flat ground if both sides/ middle are same height off the ground. The forward axle takes a beating from curbs if driven by a novice.

I have had that problem with smaller trailers in the past and it was both issues in my case.

Is there feathering of the tread as well? If so, it sounds like a toe in/out issue. You can use a tape measure to check it, measure the front vs back on the tread of the tire, you'll be able to tell very easily. Do you have torsion or spring suspension?

What is the model number stamped in the top of the i beam behind the tongue jack ? Prehaps trailer is not rated for the boat you hauled on it ? Tire size ? 5 or 6 lug ?

Take the trailer in for allignment. They all need it once in a while. Will help tire wear and it will tow better.

I have had this problem on a brand new triple axle trailer. Did allkinds of measuring everything checked out ok. Put Goodyear tires on problem went away. Michelin's are good also.

Could have bowed the front axle from too low a tongue height also. Depending on the trailer and the type of axles there are some that you can tow with the tongue too low and it will allow the front axle to bottom out easily. Enough bumps and jolts and you have a bent axle.

I had same type issue and was tires. I bought brand new tandem from a local reputable trailer builder, right away the tires wore goofy, I am pretty good with pressure and maintance so knew that was not the case. I orginally thought it was outta alignment issue and took it to have it checked. The dealer said he bets it is the crap tires he tried for short while (, they were low profile TowMasters bias). Sold me GY Marathons for cost and problem went away, have tons of miles on it and tires wearing perfectly.