Help with wheels and backspacing

[Devil Frog]

Just sold my 31X10.5R15s with the steelies.

I am going with to install the 2.5" OME/Dakar lift, and want to run 33x12.5R15s on 15x10.5 rims. Pro Comp has steelies with 3.75" back space, I have not ordered the rims yet because I am not sure about the back spacing. I have a front axel with disc conversion (monte carlo I think?) would like to avoid a spacer.

 

[Groundhog]

I have 33x12.5 on 17" rims with no backspacer you can come over and measure.

 

[jstncse]

That is going to stick out a lot. I think you would want something closer to center, maybe a 4.75 backspacing.

 

[2manycruisers]

I personally wouldn't put them on 10" rims, I think they are too wide. Regardless of the width you choose, though, 3.75" is too much backspacing for a stock disk brake front axle with 15" rims. Actually, I think it's too much for a drum brake axle, too, because the rim hits the tie rod, not the caliper. If you step up to 16" or 17" rims, you can run more BS. IIRC 3.5" is the max BS on a 15" rim without a spacer.

 

[pappy]

I am going with to install the 2.5" OME/Dakar lift, and want to run 33x12.5R15s on 15x10.5 rims. Pro Comp has steelies with 3.75" back space, I have not ordered the rims yet because I am not sure about the back spacing. I have a front axel with disc conversion (monte carlo I think?) would like to avoid a spacer.

Tacoma or FJ40?

That is going to stick out a lot. I think you would want something closer to center, maybe a 4.75 backspacing.

On the FJ40 the factory backspacing was either 3.5" or 3.75". Can't remember. I'm running 3.5" steel on the FJ40, and 3.75" alloy on the 4Runner. The factory steering on the 4Runner hit the rims. As David says below, it hit the tie-rod. The x-over steering is no problem.

I personally wouldn't put them on 10" rims, I think they are too wide. Regardless of the width you choose, though, 3.75" is too much backspacing for a stock disk brake front axle with 15" rims. Actually, I think it's too much for a drum brake axle, too, because the rim hits the tie rod, not the caliper. If you step up to 16" or 17" rims, you can run more BS. IIRC 3.5" is the max BS on a 15" rim without a spacer.

Agree with David. An 8" rim would be better and I would look for 3.5" backspaced wheels. Of course, assuming you are talking about the FJ40. I have a set of 33x12.50-15 on 3.5" wheels if you want to try them for fit. Steel wheels do have a reputation for rubbing on calipers. They do on mine, both the FJ40 and the 4R so I run a 1/4" spacer. But then, I am running the V6 mini calipers which are larger.

 

[Devil Frog]

I personally wouldn't put them on 10" rims, I think they are too wide. .

the tire that I will run is a GY Duratrac 33x12.5r15, the approved rim width is 8.5-11" so 8" rim is just out of spec

Wrangler DuraTrac | Goodyear Tires

So I guess will look for a 15x9 or 10" rim with 4.75" BS

 

[Devil Frog]

Tacoma or FJ40?

.

for the 40

 

[Devil Frog]

I am thinking a LT285/75R16 will be a better option as it will fit on a 16x8 rim

 

[Devil Frog]

12.5 wide tire on 8" wide rim?

There is an inconsistancy on tire MFG specs for 12.5" tires and minnum rim width. Many tire companies say that a 12.5" wide tire can be mounted to an 8" wide rim. Goodyear specs a minum rim with of 8.5". Has anyone run a 12.5 GY on a 8" rim? If so any problems?

 

[pappy]

32x11.50-15 BS Dueler AT on a 8" rim.
33x12.50-15 GY MTR on a 8" rim.
33x12.50-15 BFG MT/KM on a 8" rim.
35x12.50-15 GY MTR on a 8" rim.

No problems.

 

[pappy]

So I guess will look for a 15x9 or 10" rim with 4.75" BS

I'm willing to bet the 4.75" backspacing won't clear your steering. Try a 3.5" backspaced wheel before you buy. That way you can take some measurements.

 

[jstncse]

I'm willing to bet the 4.75" backspacing won't clear your steering. Try a 3.5" backspaced wheel before you buy. That way you can take some measurements.

I agree with Pappy. I didn't realize the stock offset was so shallow, I would go with an 8" rim wit a 3.5 back spacing. Running a 12.5 tire on an 8" rim is not a problem.

 

[sl33p3]

There is an inconsistancy on tire MFG specs for 12.5" tires and minnum rim width. Many tire companies say that a 12.5" wide tire can be mounted to an 8" wide rim. Goodyear specs a minum rim with of 8.5". Has anyone run a 12.5 GY on a 8" rim? If so any problems?

i have 285/75R16 Dtracs on my oem 80 rims 8" wide. discount didn't wince at install, i haven't had any problems...

 

[Rudical]

I am thinking a LT285/75R16 will be a better option as it will fit on a 16x8 rim

i have 285/75R16 Dtracs on my oem 80 rims 8" wide. discount didn't wince at install, i haven't had any problems...

I have 305/70R16 GY MTR's on my stock 80's rims. No problems,on my truck just like John.

 

[Devil Frog]

Okay, went ahead and ordered 5 GY DuraTracs @ 33x12.5R15 and Pro Comp 52 series 15x8" with 3.75" BS. The rims I had on my 31s were 15x7, with 3.5" BS- no interference, so let see if I need a spacer

 

[BionicCruiser]

my bet is you will need one. I had 15x10's on mine for the 36x14.50 tires for a while and I ordered 3.5" backspace and they came in labeled as 3.5 w/ actual measurement of 3.75. they hit the rod end.
I had a terrible time finding 3.5" backspaced steel rims. IIRC, that's how I ended up with aluminum rims.