Fitting 33/12.50

Bust out a bfh and go to town on the pinch weld area. Im running 15x10s on 35s now. But when i had 33s, i had zero rubbing.

Here she is on 33x12.5. Same rims.

I know...she looks odd

 

A post from another member corrected me. I was thinking of 12 wide wheels, not 10. It also looks more in place on a rig that’s plenty built like yours.

 

Hell yes to this..

I run stock 15/7 steel wheels with 33/10.5 tires. Castor is maxed out, I’m still using stock uca’s. No rub at all. That’s with the coil over out and fully compressed.

 

The 98-00 front end look is definitely underrated

 

So hold up guys, can we really fit 33/10.50s or 33/12.50s without rubbing by maxxing out the caster??

 

With a bfh it can be done

 

It's not necessarily that simple, but yes. Having more caster pushes the lower control arm forward while leaving the upper in the same place.

That has the effect of pushing the tire away from the firewall at ride height. The more compressed the suspension is, the closer the tire gets to the firewall, because you didn't change the location of the upper control arm the tire just follows a different arc to roughly the same position.

If you're just driving on the street and light wheeling, then nothing more than caster and a light pinch weld trim is needed to fit a 33x12.50 on 15x8's. 10" wide wheels will take a little more because that makes the tire's scrub radius quite a bit wider.

With a reasonable amount of trimming and pounding back the firewall a bit clearing just about any 33" setup completely is doable.

With stock UCA's you actually only want around 2" of lift in the front, once you get closer to 3" of lift pulling the control arm forward is considerably more difficult.

 

Bringing this up again.

Anyone with a 2.5" front end lift with SPC UCA can share their exact setup to clear 33x12.5x15?

What setting for the spc uca star plate?
Did you max out caster with the lower control arm?
Are you running a wheel spacer and if so, what size?

I've done the pinch weld mod and I still rub on full lock. I have a 2 different sets of wheel spacers to test out. Currently testing the 1.5" wheel spacers and still rubbing on the fender on full lock. I'll have to test out the 1" spacer.

Took the truck to an Indie shop I always go to for alignments. They said they could only get 0.5 more degrees of caster for a total of 2.0 - 2.2 degrees.

My spc uca is set at position D. What am I missing? Try another shop? I prefer not to do a body lift.

Any input is appreciated.

 

To clear those with minimal cutting, you are for sure going to need to get the SPCs to setting G; moving the wheel as far forward as possible. I am running 255/85R16 (33x10.5", essentially) and had to move them to the G setting to reduce rubbing. This will reduce your caster, so there's a tradeoff there - some people are OK with that; others aren't. Note: you could get SOLO LCAs to add a bunch more caster via the LCA (moving the wheel quite a bit forward), but that's not a cheap solution.

Your real solution is going to be narrower tires, or more bashing of the pinch weld/trimming of the fender flare, that's really all there is too it. You're essentially running tires that make your setup simulate both more (frame rub) and less (fender rub) backspacing at the same time. As described here. There is litterally a diagram of 12.5" tires there.

Oh, and the other thing - all the people that tell you they "don't rub" with 33x12.5's... they are either not exercizing their suspension, have bashed+trimmed a bunch, or are not being honest with themselves.

 

Thanks. I've been thinking about exactly what you said on the caster. Some threads just say to increase caster and yes I want to increase caster, but that doesn't necessarily mean clearance from the back fender. For example, I can swing the spc ball joint to A and technically increase caster a bunch but I would be pushing the wheel even more into the back fender.

I will try position G with the lower control arms maxed for caster and hope that it still nets at least a +1.5 degrees of caster.

 

I also understand this may be common sense. I'm just slower when it comes to alignment with this spc uca.

 

Update for anyone interested.. swapped from the 1.5" wheel spacers to the 1" spacers and saw a lot of improvement. Still rubbing on the back side of the fender plastic, but less.

Have an appointment with another shop to try and increase caster. Just need a tiny bit and I should have adequate clearance.

 

Just keep in mind, as was hinted to earlier, you can't just simply "add caster" and have that be the magic fix. It's not that simple. Adjusting your caster outside of factory spec has driveability concerns. Castor (and all the other alignment aspects) changes the handling, especially on the hwy, and tire wear.

When you are using aftermarket UCAs, you aren't really "adding caster". When you get it aligned, the angles of your wheels (the alignment) should be the same as factory specifications, but because the UCAs are longer, that forces you to "add caster" to the LCAs to match. The end result should still have the same caster values as stock.

 

Are your 1" spacers bolt on hub centric ones? Have 1.5" on now and they rub. Just having trouble finding a 1" version of what I currently have

 

Thanks. That's exactly what I am after. Just wondering what exact setup people have to fit 33x12.5s without rubbing and you bring up a good point. is everyone who is running 33x12.5s with increased caster beyond spec having wear issues and drivability issues? That's a good piece of information to understand. I have not come across many if any of those posts yet.

 

My 1" are just lug centric and I am only running them with aftermarket wheels. So far drives great.

Now if I can solve my rubbing. Just got a call back from the shop saying they didn't have success increasing caster. Not sure if that means they couldn't or just wouldn't.

 

The other thing is to really figure out what "without rubbing" means. If you don't want it to rub *at all*, you'll going to have issues, and will need to do some trimming of something, somewhere. Or do you just not want it to rub when you're pulling into your driveway. When you're off-road, is the occasional rub at full lock and full articulation a deal breaker?

It's going to be a compromise. My tires (32's) rubbed the frame until I got uniball UCAs and re-aligned. But I can't say for sure it *never* rubs, but it hasn't yet...

Once I step up to 33's, I'm sticking with 255/85's because the skinnies generally don't rub as bad, and there are performance benefits to them as well. But I'm not going to get too wrapped around the axle about rubbing with getting new wheels or spacers or whatever. I'll check if it rubs (with 2.5" lift) and trim/hammer accordingly. If it rubs at full lock off road sometimes, that's not really a big deal.

 

yeah, i'm only looking to not rub under normal commuting driving. It rubs at full lock against the fenders and when I reverse. I already cut, molded, and pounded the pinch weld. Yes, I supposed i can learn to live with it, but if some minor caster adjustment can eliminate this rubbing from my normal driving that would be great.

So far no shop has been able to increase caster and I don't feel confident enough messing with my alignment myself. I've even gone to shops that other enthusiast here have recommended. I've paid for a handful of alignments now that haven't been able to increase caster beyond spec.

I just didn't think with so many people driving on 33x12.5s that it was going to be this tricky. Adding the SPC upper control arm makes it even more tricky, because no one knows how to adjust them. haha.

 

Yeah, definitely don't do the alignment yourself, lol. An off-road fab or racing shop would be familiar with aligning with the SPC's. It's not exactly rocket science, but some kid that only ever aligns Civics isn't going to be familiar with them. Maybe search around in the regional forums for a shop that other people have used.

But a normal everyday alignment shop probably won't add "more" caster because you ask them to, like I said, that changes how it drives and that could have liability concerns for shops. And I'd definitely recommend against adding more caster if this is a daily driver. For a daily, keep the alignment figures all within factory spec.

You said going down to a 1" spacer helped. Have you tried no spacer?

IMO, don't mess with alignment values. Mess with wheel backspacing, lift, and trimming/hammering to minimize rubbing.