Max Tire Size for Stock FJ40?

[FloridaLife]

Yes, my tires are like 27.5-inches. Now, in reality, my air pressure, psi is a ratio, and I have less area on my smaller tires. My vehicle actually makes the sidewall squish, and the tire conforms to the road, way more than it does with bigger tires, at the same pressure. Part of that is that the sidewall thickness is proportional to the overall tire, bigger tires are for more massive trucks. Sure you probably need to run big tires at slightly lower pressures.
Without removing a wheel, what does the back of the spare tire carrier look like? MIG welding was developed in the '70s, before that, riveted wheels.
Ask in the 4Runner forum about seat and running board height? I'm a big 4Runner fan, as my buddy certainly out-wheeled my cool-looking lifted 40, back before Gen2 Runners were classic. Somewhere between 84 and 86 4Runner / Pickup remains Toyota's state-of-the-art 4wd, imo.

Hmmm. Well, my Gen 3 4Runner was a 2 wheel drive, so this will be the first 4 wheel drive I've ever had. Looking forward to it.

 

[FloridaLife]

My owners manual says H78-15 came with the vehicle. I installed a set of 215/75/R15, (not 205/75R15 as in post #102) on stock wheels, no lift. I stay off of the freeway. Coker Tire cross-references H78-15 to about a 225/75R15, but that is usually a trailer-tire when I was shopping for shoes, not typically mounted on a passenger vehicle.

Because the ball joints, aka 'steering knuckle,' on the front axle are angled, not vertical to the car, or what we call the 'kingpin angle,' it allows the weight of the vehicle, and the rolling resistance of the road to make the tires point straight. On a flat surface, the car will somewhat center itself if you let go of the steering wheel. It is tuned to the tire-radius and width of the stock wheel. You can install a wider wheel, and it will allow you to also install a taller tire, while essentially maintaining the factory axle's kingpin-tune, aka 'scrub radius.'

I did 33x12.5 on 8-inch aftermarket wheels - fun ride at slow speeds, but all over the highway, back in the day. Low speeds, it was tons of fun, especially from the driver's perspective being so up there. When I bought it, the ride came with 265/75/r15 on 8-inch wheels, and that was decent for stock springs with longer shackles - it needed wedges to change the camber angle between the front spring perch and the stock leaf spring. Tighter steering components, a Saginaw steering conversion, a change in camber angle with spring perch wedges, those will also help if you are doing big tires like 33s. However, I ran out of time, money, and my rear driveshaft was a vibration nightmare on the highway.

I really think that the stock wheels look cool, but when stock equipment is paired with a taller tire, it allows the rolling resistance of the road, and the car's weight to steer for you. Lifts are nice, but, the modifications are often beyond what is often sold in a kit. I had rubbing issues with the (Rancho) lift springs that I put on with 33s. A double cardan u-joint for the rear driveshaft might have helped the vibration. I flipped the vehicle for a beater sedan, years later, during a moment of inspiration and regret, I bought my current LC.

I really appreciate all the input/info.

I've had input from several people, which has me learning towards taking the lift kit off, and taking the taller mudder tires off and going with a more stock size tire.

Thank you

 

[Grayscale]

I really appreciate all the input/info.

I've had input from several people, which has me learning towards taking the lift kit off, and taking the taller mudder tires off and going with a more stock size tire.

Thank you

Where will you find stock-size springs? I'm unaware of a source, aside from custom-springs made by Alcan, in Colorado.

 

[FloridaLife]

Where will you find stock-size springs? I'm unaware of a source, aside from custom-springs made by Alcan, in Colorado.

From the pics I posted, people here on iH8MUD have said that someone added leafs to the factory springs, so my thought was to just take those added leaf springs off.

I also remember back when I was building a '34 Coupe and a '34 4-Door there were multiple places you could find in Street Rodder and Street Scene magazines that would custom make you new leaf springs and even offered a single mono leaf that would have the same performance as a stack of leafs and a better ride. Or like for the front of my '34's I ordered coil springs custom made off the calculation of total weight including how many quarts of oil and how much coolant and have a better ride while lowering the front end a couple of inches.

 

[WarDamnEagle]

Or like for the front of my '34's I ordered coil springs custom made off the calculation of total weight including how many quarts of oil and how much coolant and have a better ride while lowering the front end a couple of inches.

So what did you do if your girlfriend gained a quart or two?

 

[FloridaLife]

So what did you do if your girlfriend gained a quart or two?

Find a new one. And with a car like that, there was a long line waiting! It was similar to ZZ Top's red Eliminator car, but better.

 

[mondo45]

Hi everyone. This is a nice discussion. I need your opinion just to make sure I'm not off. I got some power king 7.50x16s and thinking of getting the 70 series 16x6 steel wheels (part # 42601-60262-03, silver painted and I think they're pictured somewhere in this thread.) Will this be good for a stock height 78 fj40? No rubbing and such? I really like the City Racer 16-inch rims, though. Thank you for your advice.

 

[-MaTTi-]

From searching I've done, the FJ40 came originally with 205/75/R15 tires

Not true. H78-15 or 7.00-15, 7.00-16, 7.50-16, 9.00-16 have been the original tire sizes. So something between 29-33”.

 

[charliemeyer007]

I like my 235/75R-15

 

[65swb45]

We just installed 31x10.5x15 tires on factory rims onto the TekTeq cruiser with stock lift. There does not appear to be any issues with the fronts, but the rears are a little too close to the wheelwells for my liking, especially with the flex of 60 yo stock springs. So I recommended adding spacers to the bump stops to make sure that they hit before the tires contact sheetmetal.

 

[FloridaLife]

I like my 235/75R-15

Hey Charlie, I can't remember, are you running stock height suspension? If so, the chart I looked at for tires says the 235/75R-15 has a tread width of 9.3 inches, and a height of 29.1 inches. No rubbing on yours? I ask because I've been trying to decide between the 235/75R-15 and the 225/75R15 with a tread width of 8.8 inches and a height of 28.3 inches. Mine appears to have a lift kit on it, but I think I'm going to take @cruisermatt 's advice and take the lift kit off for a better ride.

 

[charliemeyer007]

Stock springs, old and really needs re-arched or something. Stock wheels. Never rubbed as far as I know. I have been lock to lock in low range low and everything on up.

 

[FloridaLife]

Stock springs, old and really needs re-arched or something. Stock wheels. Never rubbed as far as I know. I have been lock to lock in low range low and everything on up.

Thanks, good to know.

 

[Grayscale]

Hey Charlie, I can't remember, are you running stock height suspension? If so, the chart I looked at for tires says the 235/75R-15 has a tread width of 9.3 inches, and a height of 29.1 inches. No rubbing on yours? I ask because I've been trying to decide between the 235/75R-15 and the 225/75R15 with a tread width of 8.8 inches and a height of 28.3 inches. Mine appears to have a lift kit on it, but I think I'm going to take @cruisermatt 's advice and take the lift kit off for a better ride.

Are not all 225/75/R15s offered as 'trailer' tires, not 'passenger' tires.

 

[FloridaLife]

Are not all 225/75/R15s offered as 'trailer' tires, not 'passenger' tires.

No, they are offered as light truck and SUV tires too:

Toyo Open Country A/T III P225/75R15 102T Light Truck Tire - Walmart.com

Buy Toyo Open Country A/T III P225/75R15 102T Light Truck Tire at Walmart.com

www.walmart.com

Falken Wildpeak A/T4W All Terrain 225/75R15 106T XL Light Truck Tire - Walmart.com

Buy Falken Wildpeak A/T4W All Terrain 225/75R15 106T XL Light Truck Tire at Walmart.com

www.walmart.com

Robot or human?

 

[Grayscale]

No, they are offered as light truck and SUV tires too:

However, 225-75-R15 is technically out of spec for the older 5.5-inch stock wheels.

 

[FloridaLife]

However, 225-75-R15 is technically out of spec for the older 5.5-inch stock wheels.

I "think" a lot of guys with OEM wheels are running those tires and the 235/75-R15. I'm planning on running my OEM wheels, mainly because I can't afford to replace them right now.


@charliemeyer007 are you running your stock OEM wheels?

 

[charliemeyer007]

Discount Tires online tire selector wouldn't let select the 235. Since about 1983 I have bought and had installed 235 from Big-O and Les Schwab several times never with an issue. I bought my current ones on ebay or Amoron and had them mounted at Commercial Tire. I guess I'm done with Discount Tire.

 

[FloridaLife]

Discount Tires online tire selector wouldn't let select the 235. Since about 1983 I have bought and had installed 235 from Big-O and Les Schwab several times never with an issue. I bought my current ones on ebay or Amoron and had them mounted at Commercial Tire. I guess I'm done with Discount Tire.

I usually get mine from Walmart and get the Road Hazard Warranty so that no matter where I am, if I have one blow or one gets damaged I can get it replaced easily. The last time I bought 4 new tires for my 4Runner, a week later they had to replace one due to a nail. A month later I went across a train track and there must have been a sharp piece of metal that slashed a tire. Within 6 months 3 of the 4 had been replaced, so I was thankful for the road hazard and lifetime rotation & balance.

 

[FloridaLife]

Discount Tires online tire selector wouldn't let select the 235. Since about 1983 I have bought and had installed 235 from Big-O and Les Schwab several times never with an issue. I bought my current ones on ebay or Amoron and had them mounted at Commercial Tire. I guess I'm done with Discount Tire.

@charliemeyer007 are you running your stock OEM wheels?