Cooper Discoverer S/T Maxx

[Simons]

Typically if a tire is causing a pull, if you swap them left side to right the pull will follow the bad tire. So if it pulled right before the cross switch it'll pull left after. That's how a tire pull is confirmed. If it still pulls right after the cross switch then it's not the tires.
That being said I learn new stuff everyday...

 

[98GP]

Typically if a tire is causing a pull, if you swap them left side to right the pull will follow the bad tire. So if it pulled right before the cross switch it'll pull left after. That's how a tire pull is confirmed. If it still pulls right after the cross switch then it's not the tires.
That being said I learn new stuff everyday...

Not if it is the tread pattern causing the pull. The tread pattern will contact the road the in the same manner from side to side. I have wondered the same thing regarding the General Grabber MT (ones with the red letters). These tires have a very defined slant to the center tread pattern.

 

[leelikesbikes]

whiners

i just put a set in 37" flavor on my ram 2500, they are so much better that my 37" kevlar mtr's that they replaced. i haven't noticed any bad road manners, and they actually balanced! you would have to be driving down a perfectly flat stretch of highway to notice any pull, and that sounds like no fun! i thought we were all into driving offroad around here. ive been driving big tired jalopy 4x4's for so long that maybe my tire moral compass is screwed up.:sombrero:

 

[SandCuda]

Alignment Specs

This is my current alignment which appears to be in acceptable range....However I have heard that Toe should not be equal on both sides, that a 5 degree difference is needed to compensate for road crown. Is this true?

 

[Redline]

This is my current alignment which appears to be in acceptable range....However I have heard that Toe should not be equal on both sides, that a 5 degree difference is needed to compensate for road crown. Is this true?

Not the toe, but a 0.5 (1/2 degree) of caster difference, more on the right, to help compensate for road crown on a highway that drains to the right shoulder. More caster on the right steers/pushes the car left. Camber will influence the handling and tracking too, but to a lessor amount.

In recent years I've used many sets if tires, and found the need to go well beyond the 0.5 degree of cross-caster with several sets. A few have been happy with th standard of 0.5 degree.

I can't see the exact numbers on your printout, looks like maybe 0.1 degree castor difference?

Every vehicle and tire combination is potentially different and it's not unusual for a different tire to make a rig drive differently. For example, my new '14 Ram/Cummins project had a right pull when new. A baseline alignment measurement confirmed the truck was 'within spec' and already had 0.5* cross-caster (more on the right) that in theory should have helped the truck drive straight...this was with the OE, highway tread tires. But Dodges have a reputation for needing much more cross-caster, particularly with some tires. I added a 1.5 degree offset ball joint to the right-front, dramatically increasing the cross-caster, and now the truck drives straight for several seconds (up to 20+!).

The Cooper Discoverer S/T tires are great treads, and induce less of a right pull/drift than I've experienced with Toyo M/T tires, but more than some others. Your rig will vary.

 

[1stDeuce]

Sand Cuda, your pull isn't the tires, it's the .8 degrees of cross camber that you have. Camber difference from side to side has the same effect on pull as caster difference, and even more with some (wider) tires. Your left front is at almost -1.0 degrees, and your right front is at about zero. That will cause a right pull. You need either a 1.0 deg balljoint, or a 1.0 deg shim on the left front to bring that wheel to about zero camber, and I bet you'll find that the pull goes away.

Also, your caster is a little low. It should be more like 4.5 degrees. There are two hole positions on the AEV drop brackets for the upper control arms. I think they probably have yours mounted in the wrong set of holes... Check the lift instructions, or ask on the AEV forum to find out which they should be mounted in. Adding caster will increase the vehicles desire to go straight down the road.

But your problem is camber. Buy this shim and put it in on the left side and your pull will most likely go away completely. http://www.amazon.com/Jeep-Camber-Shim-1-0%C2%B0-26014/dp/B00N27PSRS
Then check the AEV lift instructions and make sure you have the UCA's mounted in the correct holes, and you should end up with about 4.5 degrees of caster, and you will be a much happier camper.

Chris

 

[1stDeuce]

Here, I stole this from AEV's instructions. Your AEV lifted JK has this bracket installed on the frame at the front upper control arm attachments. If you scoot under and look at the inside holes, you'll see where your arms are mounted. Check the hole position against the lift height that you have. Far easier and cheaper to move the upper control arm mounts than to add balljoints to get more caster. Even if you're in the correct hole for your claimed lift, going to a higher lift position hole (Uh, lower hole in the bracket) will add a degree or so of caster IIRC.

 

[SandCuda]

Thanks 1stDeuce....I think my caster is on the low side due to running a stock front end with the AEV 2.5 lift. I think if I had dual batteries and an AEV front bumper the caster numbers would probably be closer to 4.5. The upper control arms are in the upper holes of the AEV drop brackets. I have considered moving them to the center holes as my front end is a little high and loose or flighty while driving.
Having new Synergy ball joints installed next week as the factory ones are worn. Alignment will be checked after ball joint installation. I think I will install the shim if the camber numbers don't improve.

 

[1stDeuce]

All good things. Once you get your jeep fixed up the way it should be, you can stop badmouthing the perfectly good tires that you've got!

And if your nose is high, that would definitely cause the low caster, and the fix would indeed be to put the bolts in the middle holes. If you don't plan to put a bumper or winch on anytime soon, you may as well take a beer and do it this weekend. Shouldn't affect the rest of your alignment (Toe or camber) at all.

And with tight new balljoints, it'll help to have a little more caster for return to center. (You may have a bit of wandering at first due to the joints being very tight when they're new.)

 

[richard310]

You should have no issues. They are a great tire.

They performed great on their maiden voyage! On-road and off-road manners are grippy and predictable, although with this talk of the "right side pull," I am getting that even with two alignments. It's not that bad in the Xterra as some others' vehicles, but I'll be rotating this week to see if anything changes.

Richard, when you get a chance can you throw a tape on those 265s. I would love to know how they measure out. Thanks.

Sure thing. Anything specifically you need measured? I'll chalk up some quick measurements/pictures for you tomorrow (overall height/width and contact patch).

 

[kbahus]

Who has had these in the snow yet? I need some real world winter driving reviews.

 

[Silversurferyyc]

Who has had these in the snow yet? I need some real world winter driving reviews.

I'm in my second winter with mine up here in Calgary.. Very good snow traction! With ice there a little more skittish, but manageable.


Sent from my iPhone using Tapatalk

 

[snowfiend]

Anyone have the 255/80/17 on a full size? I see most pictures online of these on mid-size trucks (tacoma, etc) or on the rear of duallys but not any on a full size. Too narrow? Trying to decide between the 285/70/17 Cooper AT3's or the 255/80/17 ST MAXX for my 2013 F150 SuperCrew Heavy Duty, both are 32.8" tall. Stockers are 245/70/17 BFG Rugged Trail which are anything but rugged.

 

[Redline]

Anyone have the 255/80/17 on a full size? I see most pictures online of these on mid-size trucks (tacoma, etc) or on the rear of duallys but not any on a full size. Too narrow? Trying to decide between the 285/70/17 Cooper AT3's or the 255/80/17 ST MAXX for my 2013 F150 SuperCrew Heavy Duty, both are 32.8" tall. Stockers are 245/70/17 BFG Rugged Trail which are anything but rugged.

Not yet, but I've given much thought to pulling my 255/80s S/T MAXX from my 4Runner and mounting them on my built and heavy Tundra or my Ram/Cummins, the Tundra is the more likely recipient. It will likely be several months before/if I make this swap as it will involve alignment adjustments on both rigs and other projects are more important.

Too narrow is of course a personal preference, though I'm a big fan of 255 width LT tires, including or even particularly on full size trucks, having run 255/85R16 tires on my F-350 for most of the 18 years I owned it; loved them. 285s stuck out too far beyond the fenders for me, sucked fuel, grabbed ruts and edges more both on- and off-highway, etc.

I've never consider the 255/8x size particularly small, historically any 33x10" tire would have been considered a large tire. I consider it a normal width tire, not really narrow like a 235 nor wide like a 285 or wider size. The possible exception being the Copper S/T (not MAXX) and its variants that had an exceptionally narrow tread width compared to other 255 designs.

$0.03

 

[snowfiend]

Not yet, but I've given much thought to pulling my 255/80s S/T MAXX from my 4Runner and mounting them on my built and heavy Tundra or my Ram/Cummins, the Tundra is the more likely recipient. It will likely be several months before/if I make this swap as it will involve alignment adjustments on both rigs and other projects are more important.

Too narrow is of course a personal preference, though I'm a big fan of 255 width LT tires, including or even particularly on full size trucks, having run 255/85R16 tires on my F-350 for most of the 18 years I owned it; loved them. 285s stuck out too far beyond the fenders for me, sucked fuel, grabbed ruts and edges more both on- and off-highway, etc.

I've never consider the 255/8x size particularly small, historically any 33x10" tire would have been considered a large tire. I consider it a normal width tire, not really narrow like a 235 nor wide like a 285 or wider size. The possible exception being the Copper S/T (not MAXX) and its variants that had an exceptionally narrow tread width compared to other 255 designs.

$0.03

Thanks for the feedback, any experience with the ST MAXX in the snow? I actually ordered the AT3's on Friday but just saw the 255/80 ST MAXX and am thinking about changing my order.