I have a 1989 F150 rear wheel drive. Can I put dual wheels on the back axle? How hard is it to do this?

JC Whitney used to sell adapters and fender extensions to do this, but I’m not sure if they do anymore or not. You might check their website or request a catalog.

For an F150 I’m not sure why you would want to. Weight carrying will still be limited by the chassis though it will handle weight with more stability. A 3/4 ton it isn’t and never will be. The only thing you add is flotation and being that it’s 2wd, you’ll not be taking it anywhere you need it; at least you shouldn’t be. If you drive in snow, it will be really bad traction wise with out 4 wd. IMO, it’s too much to do for a truck this old for looks.

First, you would need a replacement box for a setup for dualies. Second, you’ll need to replace rear differential assembly for the proper gear/axles/and rear brakes for dualies. And third, I doubt that gas engine provides enough torque to get those dualies rolling.

Sounding expensive?


In addition to what dagosa said, the brakes, the springs, the engine, and the transmission were also not designed for the additional weight.

This is not a good idea. If you need additional payload capacity, get a truck that was designed for it.

My neighbor did this with his old unlicensed dedicated plow truck which we all took turns plowing our private road with. It was 4wd and we lost so much snow traction he reverted back after half a winter of fruitless plowing. The only advantage, it was more stable throwing sand off the back on the road and trimming trees from side hill lies…that was it. He couldn’t carry more sand. And did I mention, the ride was worse with the added unsprung weight and it was terrible parking and maneuvering in tight quarters.
Now, on the one ton dump we used at work, a different story…you need it.

It is difficult to imagine any benefit to such a modification.

And just driving it anywhere but the open road is a pain - lots of extra width to remember.

Ok. Sounds more complicated than I thought and more money than I have. Thanks

Now what could I do to get a little more hp out of the engine? I live near a junkyard, so could I take engine parts from bigger trucks/vehicles and swap them with the ones on my truck?

Short of a larger, more powerful engine there is nothing you could yank out of a junkyard (other than a supercharger) that will increase power.

Even if the supercharger were free it will require time, aggravation, and $ to install and set up correctly.

If the truck has a 5.0 you could swap it out with a 5.8.

Next step would be to drop in a 460. That would give it some grunt and even make the gas gauge scream for mercy.

There’s no cheap solution to more power unless you happened to find someone willing to trade a larger motor even up for what I assume is a 5.0 and can do the work yourself.

Do you have any good reasons for your dually or more hp ideas other then just to do it?

like ok4450 stated…a junk yard wont do much for you. But there are always some little things you can do for free or very little cost that will improve hp a little. Like for instance putting a short belt on to bypass some of your un needed accessories. Another thing that was very common with the 80s 5.0 mustangs was to advance the timing. Thats pretty easy and free. Dont advance it too much though or you start to lose hp…and will need a new motor.

You can check the rear axle ratio and if it is very tall, i.e. 3.40 or lower, swapping a junk yard axle with a stump pulling ratio will improve acceleration and pulling power at the cost of top speed and fuel mileage.