2021 Rims on a 1999 | Ford Explorer Forums - Serious Explorations

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2021 Rims on a 1999

So I am not the best with off-set, so maybe you can help me.

My 1999 Mountaineer has the 15" rims, 7" wide, and ET12. (5.0, AWD)

A 2021 Lincoln Aviator has some cool greyish rims, 8" wide 19" diameter, with an ET37.5.

On the 99, from the centerline (at 3.5") the offset is 3", right?
On the 21, from the centerline (at 4") the offset is more like 3.5"?

So the 21 rims sit 1/2" deeper, or closer to the suspension?

I also understand the hub would need bored maybe to fit the 99, out to like 70.5mm or something.

I think these would look great, not sure I want to tackle boring them and spacers, but thought it was a good exercise for me to learn.
 



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Buy appropriate rims vs spacers and modifying the wheels.
 












Yes, offset wrong, center bore too small. Don't steal the wheels off a '21 to get free tires, lol. ;)
 






I don't think those 2021 wheels can work. What is the bolt circle, didn't they change most to metric years ago?

The offset figures already tell you what you asked. Don't confuse things by trying to reverse the math and make them back spacing figures.

The old wheel offset is 12mm, the new ones are 37.5mm, the difference is 25.5mm, which is one inch, not 1/2". The offset is the distance from the hub surface, to the centerline of the wheel.

BTW, 35mm is too much for the 2nd gen trucks for a wide wheel. I have 18x8.5" wheels with 35mm offsets, and those required spacers to clear the upper BJ's in front. About 30mm is the limit to fit an 8" or so wide wheel on the 2nd gen trucks.
 






It won't work, I guess it will be best to just buy aftermarket wheels on shops like 4WheelOnline. You can find a lot of affordable rims that will fit this car on the internet nowadays.
 






I don't think those 2021 wheels can work. What is the bolt circle, didn't they change most to metric years ago?

The offset figures already tell you what you asked. Don't confuse things by trying to reverse the math and make them back spacing figures.

The old wheel offset is 12mm, the new ones are 37.5mm, the difference is 25.5mm, which is one inch, not 1/2". The offset is the distance from the hub surface, to the centerline of the wheel.

BTW, 35mm is too much for the 2nd gen trucks for a wide wheel. I have 18x8.5" wheels with 35mm offsets, and those required spacers to clear the upper BJ's in front. About 30mm is the limit to fit an 8" or so wide wheel on the 2nd gen trucks.

I had done a bunch of searching online and here, wanted to make sure I got it right.

I thought going to 1" wider rim, which is 1/2" each side from centerline, would get a deduct from the 1" difference in 37.5 minus 12. One reason I was asking.

Thank you.
 






The offset is only the measurement of the centerline, the wheel width is additional change to calculate.

Yes a 1" wider wheel means 1/2" more is inboard. But the offset changing 1" inboard also matters a ton. That 2021 wheel would set 1.5" farther inboard than the stock wheel.

The offset is stamped into the back of most wheels. The ET12 is the stock offset, that's 12mm, or very close to 1/2"(6.35mm is 1/4" exactly). So the 2021 wheels are ET37.5, the offset.
 






It won't work, I guess it will be best to just buy aftermarket wheels on shops like 4WheelOnline. You can find a lot of affordable rims that will fit this car on the internet nowadays.

I had found some 56 mile take offs that look awesome and not bad $$$, I drive 4k miles a month, I spend what I need to spend like good tires, but I don't see me spending on aftermarket wheels. I just got this 99 Merc with 90k miles (5.0 awd) and probably drive it till March and then set it aside for the kids - so I'll be research shocks/struts for it and stuff too
 






Very good, your kids will love the truck if it's well taken care of, and it'll last for a long time even at this age. The key is maintenance, typical normal things. But at this age, most of these have been neglected to some degree. So you need to spend some time inspecting things, and look for common issues. The front suspension seems to be #1 to be ignored, some trucks will have new parts there, but many will have original, which needs to go.

If you don't know how old anything is, I'd replaced all fluids, filters, the plugs and plug wires, and all belt pulleys that can be, and the belt. With high mileage and old age, the front O2 sensors are good to replace also.


Keep a close watch on the tires, if they are not the same size(wear) all the way around, the AWD will be forced to make a lot of heat. It's sole purpose is to maintain the same speed of the front and rear driveshafts. If you have mismatched tires, the viscous clutch inside the AWD will be running very hot, like a person riding the clutch constantly. It won't destroy it immediately, but it may be toast in a month or a year, depending on the tire wear difference(front to back). Tires are easy to change, the AWD is over $1000 for a rebuilt unit.
 






Very good, your kids will love the truck if it's well taken care of, and it'll last for a long time even at this age. The key is maintenance, typical normal things. But at this age, most of these have been neglected to some degree. So you need to spend some time inspecting things, and look for common issues. The front suspension seems to be #1 to be ignored, some trucks will have new parts there, but many will have original, which needs to go.

If you don't know how old anything is, I'd replaced all fluids, filters, the plugs and plug wires, and all belt pulleys that can be, and the belt. With high mileage and old age, the front O2 sensors are good to replace also.


Keep a close watch on the tires, if they are not the same size(wear) all the way around, the AWD will be forced to make a lot of heat. It's sole purpose is to maintain the same speed of the front and rear driveshafts. If you have mismatched tires, the viscous clutch inside the AWD will be running very hot, like a person riding the clutch constantly. It won't destroy it immediately, but it may be toast in a month or a year, depending on the tire wear difference(front to back). Tires are easy to change, the AWD is over $1000 for a rebuilt unit.

Yes, I already have most the PM parts and stuff, I have a handful of old Ford iron. The only thing I haven't researched yet is the AWD transfer case and whats best to do for it. The 4R70w will get serviced and plugs etc, check ujoints and front end all in process now. I had good luck with the Z36 brakes on an F150, I was going to search this forum and see what people like for discs/pads, and I need to check the front wheel bearings/hubs while I rotate tires
 






Change the AWD fluid, which is the old Mercon or Dexron III(still available and the cheapest). That fluid is separate from the internal viscous clutch(which is sealed with its own fluid). So the TC fluid should always look like new, change it often if needed. The newer vehicles had issues with the newer ATF's(Mercon V etc), so they began making special TC fluid(high dollar). Then they changed the name(probably the same thing as the first Mercon, then a 3rd version. Now Valvoline makes a TC fluid, that's a favorite brand of mine, and it was $30 for six quarts on Amazon in 2019. So I suggest getting the Valvoline if you can, any Dexron III is a cheap quick choice, and the high dollar versions will be $20 or more per quart.

I prefer the Motorcraft SD brake pads, rears don't matter much, but those upper level Ford pads last me as long as anything. I'm a rural mail carrier, I know brakes. Rock Auto has the pads for about $50 normally, they have so many you have to look closely through their groups.
 






I had found some 56 mile take offs that look awesome and not bad $$$, I drive 4k miles a month, I spend what I need to spend like good tires, but I don't see me spending on aftermarket wheels. I just got this 99 Merc with 90k miles (5.0 awd) and probably drive it till March and then set it aside for the kids - so I'll be research shocks/struts for it and stuff too
No struts. 4 shocks. I’d swap out the brake fluid and power steering fluid as well. Old fluid will make the pump whinier and louder.
 






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