Rim sizes

[Tonka]

Anybody know if I can take the 15" rims off my '88 F-150 and put them on my '89 Ranger? I'm about 1100 miles away from either of those trucks at the moment.

The idea, once I do all the math, is to drop my axle ratio one size, then put oversize tires on the truck to correct the final drive ratio so it's back to stock. What I want to do is have the ability to put my 14" rims and tires back on it whenever I tow my camper, but run the 15's normally.

If I go to the junkyard to get the rims, can I just tell them to give me 15" rims for an F-150? Or do I gotta tell them it's for a newer ranger? Explorer, Aerostar, etc? I'm pretty sure I've seen 15" rims on newer Rangers.

 

[adsm08]

150 rims won't fit. The bolt pattern is wrong. Ranger pattern is 5x4.5, F-150 is 5x5.5.

Newer Ranger rims will fit.

I have a set of Aluminum mags from an 88 B2 sitting in my garage. They are for sale if you want 'em.

But tire size is more important than rim size for what you are trying to do here.

 

[Tonka]

Here's what I figured out. To maintain the effects of my stock equipment, (3.45 rear end, 215/70R14 tires with 25.9" tread diameter) I will need a 3.73 rear end and tires with an outside tread diameter of 28" which would be a 235/70R15 unless there's a tire that'll fit the 14" rim and give me that tread diameter. I don't want "balloon" tires with flexible sidewalls that'll be likely to enable trailer-sway. I want some side-load stiffness, so I'm thinking the 15" rims will work better.

There's a page on this website that explains rims but didn't really help. There was a lot of useful "blah blah blah" (as I interpreted it) that would be helpful if I was looking for fancy aftermarket rims that would clear my front brake calipers, but what I was looking for is info about what to tell the guy at the junkyard what type of vehicle I need two rims for. If I say 89 Ranger I'll end up with 14" rims. I haven't converted the truck to a twin axle 6x6, ....... yet..... so I don't need 6 identical rims at this time.

If all the conversions and calculations are correct, the result will be no change in final drive ratio from stock (accurate speedometer) with the 15" tires, but when I put the 14's back on, I'll have the speedo showing 70 mph when I'm actually going 64.75 mph. That'll be for towing.

 

[adsm08]

If I say 89 Ranger I'll end up with 14" rims.

Not necessarily. There were several rim options (notice I say OPTIONS there) in 89. There were 14" steelies, 15" steelies, and several styles of 15" aluminum rims.

All three of my RBVs came stock with 15" rims.

 

[Tonka]

So I guess now my only issue would be how accurate are the3 calculators I used that are in this site's technical pages section? I used the "gears needed after adding larger tires" calculator, the "metric tire size to inches" calculator, and the "road speed after gear change" calculators to arrive at the conclusion that a 3.73 rear end running 235/70 R15 tires (assuming a 28" tread diameter according to the metric tire calculator) would give me the same overall ratio as a 3.45 rear end running my dinky little stock 215/70 R14's. (The 235/70 R15's happened to be the "example" tire the metric conversion calculator used in it's explanation, I just happened to notice it said 28" OD.)

So I'm assuming I'll have no problem with tire clearance if I use the stock steel 15" rims off a ranger? Provided the rims don't stick OUTWARD any more, they'll clear the body metal even when the suspension is bottomed out. And if I'm hauling or towing anything i'll be using my 14" tires anyway.

 

[cody93]

fyi, the 4x4 rangers and B2's had 15 inchers stock, 2wds were 14, i found out the hard way when i bought a replacement spare tire for my 2wd ranger from someone with a B2. if memory serves me correct, the 15s arn't much wider than 14s, but i could be wrong, i only used it once, on the rear axel. if your switching to 15s for gearing, mabey use 2 ranger 4x4 15 inch steelies in the rear?

 

[straycat]

I would not change gear ratio for any tire under 31 inches, Bro. Not worth the cost to do so. Jeep wheels (Wrangler) will work as well on the Ranger. I have used them before. Buy some of the black style wheels, they look cool!!!

 

[Tonka]

I would not change gear ratio for any tire under 31 inches, Bro. Not worth the cost to do so. Jeep wheels (Wrangler) will work as well on the Ranger. I have used them before. Buy some of the black style wheels, they look cool!!!

I have to change ratios anyway because the one in there right now is way too high a ratio. Stock is supposed to be a 3.45 but it's got a super high "mystery axle" in there with no tag. When speedo says 55, I'm going 64 in real life.

I'm talking about steel wheels from the junkyard. I'll spray them gray to sort of match the fronts. Maybe the plastic doogelies from the hubs will fit the 15" rims, maybe not.

I have a CDL license and there's a new set of regulations on the trucking industry called "CSA 2010" which means we get points on our federally maintained driving records even for things like warnings and accidents when we're not even at fault. There's no appeals process, and even if you're found not guilty of speeding, you're still stuck with those points. (Yes, I'm aware of the constitution that says we "shall not be deprived of life or liberty without due process of law" but try telling that to the federal DOT.) So I can't afford traffic tickets, even in my personal owned vehicles.

So I want my speedometer to be accurate and it's worth the trouble of swapping rims when it's only gonna make a 5 mph difference. And I'm also looking at installing aftermarket cruise. There's a thread on here about that. Seems easy enough.

 

[straycat]

Just get the speedo re-calibrated. Most 4x4 shops and performance shops will do that. I had mine done before and had no issues. It was not expensive at all. All my 2wd andn 4x4 Rangers came with 15 inch wheels. I had 2 BII and they came with 15 inch wheels (both 4x4) and some of my buddies with BII's that had 2wd came with 15 inch rims.

 

[adsm08]

Just get the speedo re-calibrated. Most 4x4 shops and performance shops will do that. I had mine done before and had no issues. It was not expensive at all. All my 2wd andn 4x4 Rangers came with 15 inch wheels. I had 2 BII and they came with 15 inch wheels (both 4x4) and some of my buddies with BII's that had 2wd came with 15 inch rims.

His speedo isn't a plug in recalibration. It also requires knowing the rear end gearing.


However it is also possible that some idjut put the wrong speedo sensor in it and that the rear end gears are correct. Also possible that the same hypothetical idjut put the wrong size tires on it.

 

[Tonka]

No, there were two idjuts involved. The first one was me, driving the truck down a gravel road with really deep wheel ruts and I high-centered the diff. Gravel or something got past the seal and next thing I know it's grinding when I'm on the gas.

The second idjut was the dude at the junkyard who gave me the wrong replacement axle after I told him "AXLE CODE 84" several times.

 

[adsm08]

OK, so now that we know you have a replacement axle, we can figure out what gears you actually have.

What tire size do you have on there?

 

[Tonka]

OK, so now that we know you have a replacement axle, we can figure out what gears you actually have.

What tire size do you have on there?

The tires are P215/70 R14. To the best of my knowledge that's what's supposed to be on there. All 4 are that size. There's no manual.

I'm not sure how accurate the speedo was before, but I noticed a big difference immediately after I swapped out the axle in 2004. I had a friend pace it with his car on the interstate. When my speedometer said 55, his Lincoln LX said 65. A few years later I ran a GPS in the truck and it was showing 64 when speedo needle was EXACTLY right over the 55 mark.

 

[straycat]

His speedo isn't a plug in recalibration. It also requires knowing the rear end gearing.


However it is also possible that some idjut put the wrong speedo sensor in it and that the rear end gears are correct. Also possible that the same hypothetical idjut put the wrong size tires on it.

Hmmm, my 83 Ranger has 33's on it and I had my 4x4 shop take care of the speedo for me and my 89 BII too with 32's on it. They just knew what to do. He should just do it that way. Most rear ends have the gear ratio tagged on it, right? All my Fords have had a tag on the rear end as far as I can recall. It is a pain buying something that has be bastardized, you know??

 

[adsm08]

Well, the math says your rear end gears should be about 2.95:1. But that doesn't make sense since that ratio was never offered in a Ranger axle.