Does anyone know what size spare came with the 2006 Harley AWD trucks? Mine has a P275/65 R 18 on a steel wheel , I think it is original but want to make sure.
Thanks for any info,
Randy

 

Randy, I suspect it IS the OEM size. That was the size of the tires on my 2005 King Ranch. The spare matched the tires on the wheels that were on the ground.

Your driver's door sticker should tell you your OEM tire size.

- Jack

 

The size on the door is 275-45-22 and on the truck now are 285-55-22.
Would this be harmful to the transmission with the spare on with AWD.

 

I see. Here's a link to a calculator: https://tiresize.com/calculator/

Your OEM tires had a 31.7" diameter. The spare has a 32.1" diameter. So there was a small. 0.4" difference.

But the new tires on the truck have a 34.3" diameter - about 2" larger than the spare.

I don't see how this can effect the transmission, but I don't like what it would do to your differential if mounted on the rear axle. If you have a locking differential, and I think you do, then it's going to have some trouble with this on pavement.

I'll assume you would be running in 2WD or AWD automatic, so I think you'd be ok if the spare was on the front.

Now, I'm hardly an expert on this, but I THINK you're in much the same position as the owner of a car with a "compact spare". It's an emergency tire, good for 50 miles at low speed. I sure wouldn't use it for more than this.

My truck has a similar setup: 275/55R20 on the ground and a 275/65R18 spare. The diameter difference is only 0.2". If I were you, I think I'd try to find a spare that more closely matches your road tires.

- Jack

 

A spare that matches the road tires may not fit in the rack.

 

Yup, that's certainly a possibility. I'd still try to get close to the road size with the spare. Two courses of action:I simply would not want to use a spare that is that much smaller.

- Jack