Mixing Radials with Bias Tires

[Bill Becker]

I have a JD 4440 that has 460/85R38 radial tires that are matched on the rear of the tractor. I purchased a set of duals that are 18.4/38 bias tires that are matched for the tractor. I have only used the duals on my farm and have not gone on the road with them until I was asked to disk a field for a friend. My question is, can I run with the duals on down the road without any problems? Would running mixed radials with bias tires harm the tractor in any way? The field is about 5 miles away. Thanks for the input.

 

[BarnyardEngineering]

The bias tires probably won't even be touching the road, so no problem at all.

Even if they are I can't see why/how they could possibly cause problems. If you had both tires bias on one side and both radial on the other, that would be a whole different thing. Then you're looking at potential premature differential failure.

 

[rrlund]

Not saying I'm right,but I've been running 18.4 38 bias duals against radial inners for years.

 

[Bob Bancroft]

If, as mentioned, the radials set higher than the duals, no problem. If you're running the radials soft, just run the duals soft too.

 

[centash]

Same here, no problem.

Ben

 

[oliverkid]

Buddy of mine has been doing this on an Oliver 1855 for 4 or so years now, radials on the tractor, bias on the duals. The only reason he wasn't to worried about it was that the tires were mediocre at best when he got the tractor so he is just running them till they are shot and going all new radials next year. One trip won't hurt but here's what happens in the long run. Since the radials want to squat the height of the tire will change. With the bias plies they don't squat as hard so even with a lower air pressure, on a hard surface where they don't sink, the bias tires will actually hold up on the radials and carry more weight. The result is that the duals and mains start fighting each other and depending on which one has more grip, one set of tires or both sets will scuff more and your road ware goes to heck. They do the same thing in the field, since the radials squat harder and have more footprint they are always fighting against the bias tires. Another side affect in both cases is increased fuel consumption. All that aside though, like I said, for one trip you won't notice much.

 

[Bill Becker]

I forgot to mention the outside bias tires are almost an inch taller than the inside radial tires. Not sure if that makes a difference or not.

 

[Bob Bancroft]

Then you're going to want to run the duals REAL soft.

 

[rustred]

differential failure how and what??

 

[ed12345]

Always put the taller tier to the inside. Easer on the bearings

 

[504]

Just make sure the tires do not rub together on the inside and you will be fine.

 

[Stephen Newell]

On a car on the highway I wouldn't mix the tires but on a tractor I can't imagine it making a difference.

 

[Bill Becker]

How much air can I put in the inside radial tires? Right now I have the inside radials at 35 psi and the outer bias tires at 5 psi.