38 inch nitto trail grapplers

[yotajeeper]

Having gone back and forth through tires I finally decided on the 38 inch nitto trail grapplers
They look great. I’m on 410s still protecting by pinion. My prior tire was a smaller 37 (35.7 mounted) these 38 are 37 inch mounted.
4.5 inch rock Krawler lift
Rubicon axles with Reid knuckles and dynatrac ball joints and Rcv shafts
Ready for the fordyce this summer

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[Jeepless]

What offset are those wheels? Any straight on pictures to see the poke?

 

[Headbarcode]

What offset are those wheels? Any straight on pictures to see the poke?

Looks like that member hasn't been around since making this thread.

I've got the Metalcloak Gamechanger on my JLUR, which is similar to Rock Krawler as far as 4.5" of backspace being recommended. For reference, here's mine with 17x9 wheels with 4.53" of backspace and -12mm offset, wrapped in 38x13.5 Milestar Patagonias...

And some more recent pics from dead straight ahead and behind...

 

[J0E]

At least for the volcanic rocks we crawl on, Nitto's have proven the most robust. The group has blown six 38" Pat's in the last 2 years. I've destroyed a couple D rated K02's. E's are better here or a Nitto with a really strong sidewall. NothrRidge4x4 has 3 or my 4 Nitto's waiting for me, same 38 as yours. Oh, and those aren't any Nitto 38's, those are the 38x13.5 wider ones. My RACELINE bead locks are sitting in the garage, although the thick Nitto's require bead lock spacers, which haven't arrived yet.

 

[Jeepless]

Looks like that member hasn't been around since making this thread.

I've got the Metalcloak Gamechanger on my JLUR, which is similar to Rock Krawler as far as 4.5" of backspace being recommended. For reference, here's mine with 17x9 wheels with 4.53" of backspace and -12mm offset, wrapped in 38x13.5 Milestar Patagonias...

And some more recent pics from dead straight ahead and behind...

I’m waiting on the GC 3.5” lift and have a set of KMC Grenade beadlocks. 3.5 back spacing with -38mm. I am going to be going with 38’s and wanted 13.5 but I’m worried now with how much those will stick out. Yours looks perfect. Problem is when selecting the lift I chose the 3.5 backspacing option and love the KMC wheels I’m having custom powdercoated. Maybe I’ll go with 12.5’s to save at least .5” of poke. :/

 

[Headbarcode]

I’m waiting on the GC 3.5” lift and have a set of KMC Grenade beadlocks. 3.5 back spacing with -38mm. I am going to be going with 38’s and wanted 13.5 but I’m worried now with how much those will stick out. Yours looks perfect. Problem is when selecting the lift I chose the 3.5 backspacing option and love the KMC wheels I’m having custom powdercoated. Maybe I’ll go with 12.5’s to save at least .5” of poke. :/

This may get a bit long, as I don't want to go the easy route by suggesting a different wheel with less backspace, because that's not an easy option on your end. You'll lose money reselling them, plus more time spent trying to find another wheel you like as much. I'm also a fan of KMC's XD series of wheels.

38's are an oddball size, so there's not enough options to afford us the ability of being too picky. Yes, your wheels will result in a 1" increase of poke compared to mine, but that is really not a big difference when standing back with both Jeeps parked next to each other. Given that, a half inch difference wouldn't be worth potentially pidgeon holing yourself in an already small enough pile of tire choices.

I see that you have a Rubicon, and I'm familiar with the 3.5" Gamechanger after about 50k miles before swapping to their new 4.5" springs and 40's, so I'll go out on a limb and assume that maximum articulation is your goal as well.

Since the fenders and liners are generally the first to limit uptravel, I chopped mine and added the most high tuck liners available that don't require major engine compartment modifications. Chopping the front will gain about 3.5" of tire clearance and about 2-2.5" in the rear. That's when the entire axle compresses at once, like dropping off a ledge. It's during the more common articulation, stuffing just one tire, that I noticed my next limiting factor to uptravel. The inner shoulder of the top of the tire hits the high tuck liners, while leaving a couple of inches of fender clearance left unused. My 4.5" backspace is the limiting factor of not being able to take full advantage of the chop.

This is where your 3.5" backspace will shine. All else being equal, you'd be able to run with at least an inch less bumpstop spacing than I can. That translates to at least a couple of inches of added wheel lift at the end of the axle, before unweighting a 2nd wheel.

This is the best pic I have that shows the unused fender clearance, while the tire was lightly rubbing the liner...

Also worth mentioning at this point, is that the 38's were hitting the rear pinch seams, which limited rear tire stuff by more than a couple inches...

To sum it up for now, your 3.5" backspace has a clear advantage and I personally wouldn't further hinder tire choice by sticking to a 12.5" vs 13.5" tire, just for the sake of a nearly unnoticeable .5" of tire poke.

I could keep going on about backspace and it's affects on off camber stability and scrub radius, but this particular post is long enough.

Cheers for now, buddy!

 

[Jeepless]

This may get a bit long, as I don't want to go the easy route by suggesting a different wheel with less backspace, because that's not an easy option on your end. You'll lose money reselling them, plus more time spent trying to find another wheel you like as much. I'm also a fan of KMC's XD series of wheels.

38's are an oddball size, so there's not enough options to afford us the ability of being too picky. Yes, your wheels will result in a 1" increase of poke compared to mine, but that is really not a big difference when standing back with both Jeeps parked next to each other. Given that, a half inch difference wouldn't be worth potentially pidgeon holing yourself in an already small enough pile of tire choices.

I see that you have a Rubicon, and I'm familiar with the 3.5" Gamechanger after about 50k miles before swapping to their new 4.5" springs and 40's, so I'll go out on a limb and assume that maximum articulation is your goal as well.

Since the fenders and liners are generally the first to limit uptravel, I chopped mine and added the most high tuck liners available that don't require major engine compartment modifications. Chopping the front will gain about 3.5" of tire clearance and about 2-2.5" in the rear. That's when the entire axle compresses at once, like dropping off a ledge. It's during the more common articulation, stuffing just one tire, that I noticed my next limiting factor to uptravel. The inner shoulder of the top of the tire hits the high tuck liners, while leaving a couple of inches of fender clearance left unused. My 4.5" backspace is the limiting factor of not being able to take full advantage of the chop.

This is where your 3.5" backspace will shine. All else being equal, you'd be able to run with at least an inch less bumpstop spacing than I can. That translates to at least a couple of inches of added wheel lift at the end of the axle, before unweighting a 2nd wheel.

This is the best pic I have that shows the unused fender clearance, while the tire was lightly rubbing the liner...

Also worth mentioning at this point, is that the 38's were hitting the rear pinch seams, which limited rear tire stuff by more than a couple inches...

To sum it up for now, your 3.5" backspace has a clear advantage and I personally wouldn't further hinder tire choice by sticking to a 12.5" vs 13.5" tire, just for the sake of a nearly unnoticeable .5" of tire poke.

I could keep going on about backspace and it's affects on off camber stability and scrub radius, but this particular post is long enough.

Cheers for now, buddy!

Damn, thank you for all the info. The jeep is not my daily, although I tend to drive it daily because my “commute” is only 25 miles round trip, 3 days a week and it’s a lot more comfortable and fun to drive then the beater Prius. I also do frequent long trips to visit family and do tattoo work. Both about 700 miles round trip. So driveability is a concern but again, I kind of know the pros and cons there with the set up I chose.

So, correct me if I’m wrong, if I wanted to get a rough visualization on the car. Going from the XR wheels (315x70x17 4.5” bs and +12mm offset) to KMC set up (38x13.5x17 3.5” bs and -38mm offset) I’d essentially be increasing poke by 3.5” correct. 1” in back spacing, 2” in offset, .5” in tire width?!

Also which fender liners did you go with? I have the AAL lights on order and just began research for fender liners.

 

[Jeepless]

Damn, I just found track n trail post and realized he has the same setup! It’s a lot of poke but I like it. Again not enough of a difference to go with a different setup! At least I don’t think. Haha

 

[Headbarcode]

Damn, thank you for all the info. The jeep is not my daily, although I tend to drive it daily because my “commute” is only 25 miles round trip, 3 days a week and it’s a lot more comfortable and fun to drive then the beater Prius. I also do frequent long trips to visit family and do tattoo work. Both about 700 miles round trip. So driveability is a concern but again, I kind of know the pros and cons there with the set up I chose.

So, correct me if I’m wrong, if I wanted to get a rough visualization on the car. Going from the XR wheels (315x70x17 4.5” bs and +12mm offset) to KMC set up (38x13.5x17 3.5” bs and -38mm offset) I’d essentially be increasing poke by 3.5” correct. 1” in back spacing, 2” in offset, .5” in tire width?!

Also which fender liners did you go with? I have the AAL lights on order and just began research for fender liners.

I've got about 3-3.25" of tire poke in the front. That's measuring from the outermost bulge of the sidewall of my 38x13.5 Milestar Patagonias to the outermost lip of the chopped fender. Different tires can bulge differently, which may skew that measurement. Also, the lower half of the fender, which I deleted, sticks out further than the upper half, which definitely skews that measurement.

If I had to guess, I'd say that you will probably end up with about 4" of poke, maybe a bit more, after chopping your fenders. Personally, I find that to be the perfect range of poke. It not only looks great and overall proportionate to a lifted Jeep on bigger tires, but it also offsets the higher center of gravity in everything from on road curves and corners to off camber offroading.

I also have the AAL lights and went with their front and rear liners finished in satin black powdercoat. I highly recommend their fender retention hardware kits, which replace all of the white clips that the factory uses to attach the fenders. They consist of high quality bronze nutcerts, stainless Allen button head bolts available in either polished finish or black, and special nylon washer blocks that perfectly fit the square holes along the inner fender lips. They give the chopped fenders a more solid and rigid hold to the body, whereas the white clips may leave them feeling a bit loose.

One heads up, when it comes to most liners including AAL's. They will need to be modified to fit the new arch created by trimming the pinch seams of the body. How much depends on how much is trimmed off the seams. And how much that needs to be trimmed off of the seams will depend on the actual size of your tire choice, and whether or not you adjust the rear control arms to center the axle fore and aft in the wheelwells to counter their forward shift from the suspension lift.

Hope that last part made sense.

 

[Headbarcode]

@Jeepless

Forgot to add some pics of my mud splattered AAL liners (with hardware kits, back before black bolts were an option) and before and after shots of my trimmed seams...

 

[DLW]

Damn, thank you for all the info. The jeep is not my daily, although I tend to drive it daily because my “commute” is only 25 miles round trip, 3 days a week and it’s a lot more comfortable and fun to drive then the beater Prius. I also do frequent long trips to visit family and do tattoo work. Both about 700 miles round trip. So driveability is a concern but again, I kind of know the pros and cons there with the set up I chose.

So, correct me if I’m wrong, if I wanted to get a rough visualization on the car. Going from the XR wheels (315x70x17 4.5” bs and +12mm offset) to KMC set up (38x13.5x17 3.5” bs and -38mm offset) I’d essentially be increasing poke by 3.5” correct. 1” in back spacing, 2” in offset, .5” in tire width?!

Also which fender liners did you go with? I have the AAL lights on order and just began research for fender liners.

Just FYI, you don't add backspace and offset together, you use one or the other.
In your case, your going from a 4.5" BS to a 3.5" BS, so you get 1" more poke, plus however much wider the tire might be, so ~1.5ish inches more poke than you have now.
Edit: plus if the wheel width is different then that needs to be added as well.

I have 3.5" BS KMC wheels now with 38's.
New setup will be 4.5" BS with 40's.

There is give and take when choosing BS.
4.5" BS will get better scrub radius and be a bit easier on ball joints, less poke.
3.5" BS will get you a bit more clearance in the extreme articulation area.

@Headbarcode explained pretty good.

 

[Headbarcode]

Just FYI, you don't add backspace and offset together, you use one or the other.
In your case, your going from a 4.5" BS to a 3.5" BS, so you get 1" more poke, plus however much wider the tire might be, so ~1.5ish inches more poke than you have now.
Edit: plus if the wheel width is different then that needs to be added as well.

I have 3.5" BS KMC wheels now with 38's.
New setup will be 4.5" BS with 40's.

There is give and take when choosing BS.
4.5" BS will get better scrub radius and be a bit easier on ball joints, less poke.
3.5" BS will get you a bit more clearance in the extreme articulation area.

@Headbarcode explained pretty good.

Thanks, buddy!

It's hard to go by the xr wheels because I just don't see how they are coming up with 4.5" backspace, meanwhile the outer sidewall is still flush with the fender. I know they added an extended lip to the xr fenders, but it's what, a half inch? My wheels have 4.5" of backspace and I have over 3" of poke. Just doesn't seem to line up. Are xr fenders wider than a regular Rubicon, I wonder. Just strange.

Just out of curiosity, why are you increasing backspace with a taller tire? It'll cost some uptravel. Is it due to scrub radius concerns? If so, I can fully understand. That was my concern as well, otherwise I would've gone with 3.5" bs.

My future plan includes a set of 72.5" axles paired with 8 lug wheels that will also have 4.5" bs. Amongst all the other benefits, it'll buy me more uptravel by getting the inner tire shoulders away from the liners, while keeping scrub radius in check.

 

[Jeepless]

I've got about 3-3.25" of tire poke in the front. That's measuring from the outermost bulge of the sidewall of my 38x13.5 Milestar Patagonias to the outermost lip of the chopped fender. Different tires can bulge differently, which may skew that measurement. Also, the lower half of the fender, which I deleted, sticks out further than the upper half, which definitely skews that measurement.

If I had to guess, I'd say that you will probably end up with about 4" of poke, maybe a bit more, after chopping your fenders. Personally, I find that to be the perfect range of poke. It not only looks great and overall proportionate to a lifted Jeep on bigger tires, but it also offsets the higher center of gravity in everything from on road curves and corners to off camber offroading.

I also have the AAL lights and went with their front and rear liners finished in satin black powdercoat. I highly recommend their fender retention hardware kits, which replace all of the white clips that the factory uses to attach the fenders. They consist of high quality bronze nutcerts, stainless Allen button head bolts available in either polished finish or black, and special nylon washer blocks that perfectly fit the square holes along the inner fender lips. They give the chopped fenders a more solid and rigid hold to the body, whereas the white clips may leave them feeling a bit loose.

One heads up, when it comes to most liners including AAL's. They will need to be modified to fit the new arch created by trimming the pinch seams of the body. How much depends on how much is trimmed off the seams. And how much that needs to be trimmed off of the seams will depend on the actual size of your tire choice, and whether or not you adjust the rear control arms to center the axle fore and aft in the wheelwells to counter their forward shift from the suspension lift.

Hope that last part made sense.

thank you for all the clarification and detailed information. I appreciate the help more than you know. Thank you for the pictures too. I’ll be looking into the AAL liners and retention kit and will be doing the pinch seam chop as well. I’m going to be doing the front steering as well (tie rod, drag link and steering stabilizer) maybe I’ll look into ball joints, although I was going to wait for the time being.

Thank you @DLW, about offset and back spacing. The wheel width will be 1” wider as well (8” to 9”) so that helps knowing. Thank you for the input everyone! Just waiting on parts but should be able to get this all done in the next month or two and will post some updates once completed.

 

[Jtclayton612]

Thanks, buddy!

It's hard to go by the xr wheels because I just don't see how they are coming up with 4.5" backspace, meanwhile the outer sidewall is still flush with the fender. I know they added an extended lip to the xr fenders, but it's what, a half inch? My wheels have 4.5" of backspace and I have over 3" of poke. Just doesn't seem to line up. Are xr fenders wider than a regular Rubicon, I wonder. Just strange.

Just out of curiosity, why are you increasing backspace with a taller tire? It'll cost some uptravel. Is it due to scrub radius concerns? If so, I can fully understand. That was my concern as well, otherwise I would've gone with 3.5" bs.

My future plan includes a set of 72.5" axles paired with 8 lug wheels that will also have 4.5" bs. Amongst all the other benefits, it'll buy me more uptravel by getting the inner tire shoulders away from the liners, while keeping scrub radius in check.

IIRC the XR beadlocks are measured like the mopar beadlocks. Which end up having a 5” or so backspace because when using the beadlock setup the wheel gets .5” wider magically, aka you still have to deal with a 5” backspace wheel but for some reason when it’s mounted regularly not in beadlock mode they knock off the extra .5” and call it 4.5

 

[Headbarcode]

thank you for all the clarification and detailed information. I appreciate the help more than you know. Thank you for the pictures too. I’ll be looking into the AAL liners and retention kit and will be doing the pinch seam chop as well. I’m going to be doing the front steering as well (tie rod, drag link and steering stabilizer) maybe I’ll look into ball joints, although I was going to wait for the time being.

Thank you @DLW, about offset and back spacing. The wheel width will be 1” wider as well (8” to 9”) so that helps knowing. Thank you for the input everyone! Just waiting on parts but should be able to get this all done in the next month or two and will post some updates once completed.

Anytime, buddy! And im looking forward to seeing some pics and reading your thoughts on how it turns out.

And I agree, no need to rush into ball joints prematurely. You already know to keep an eye on them and that they will eventually need to be upgraded. If memory serves, don't you already have nodular iron knuckles on your XR? If so, that's one less cost of big tires and ride height. After some miles down the road, it'll also be ready for a pair of hub and bearing assemblies that can be done when swapping ball joints.

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