Is the JKS max clearance kit always necessary for 37 tires?

[BroncoStang]

My factory Goodyears are at the end of their service life so I'm replacing them but I've been seriously considering 37" tires.

I like the factory Sasquatch wheels my Wildtrak came with so I really don't want to replace them.

- I'm on a 2.25" Zone lift & level kit.
- I'm torn between 1" or 1.2" spacers, but either from what I've gathered should work with 37" tires and my lift.

One thing I'm still not totally clear on, is the JKS max clearance kit still required once the lift and spacers are on to clear 37s?

I do wheel my Bronco and need to keep as much articulation as possible, so if I need the kit then I'll order it but I'm just unsure.

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[CitrusBronco]

You can always start with trimming the crash bar and see for yourself if it works for you or not.
I ended up with the jks kit, the lugs on my mud terrain kept catching it.

 

[Squatch]

You can always start with trimming the crash bar and see for yourself if it works for you or not.
I ended up with the jks kit, the lugs on my mud terrain kept catching it.

I'll second removing the crash bars now and you'll know whether or not you need it soon after you get the 37s on there.

 

[Fordified1]

I trimmed the corners off my crash bar mounts (see picture) which rubbed immediately (turned at full lock on flat ground)and front inch off my factory rock sliders (not sure this was absolutely necessary but gave room for mudflaps not to rub). Slight non audible rubbing with +12 offset wheels but have only done mild trails so far. I plan to do the stinky fab front body mount replacement, which requires welding, but haven’t had time yet.

 

[KABQ]

You'll definitely have to cut the rears off. I only have the slightest rub up front with 1.25" spacers flexed out at full lock. I've been on here long enough to have some residual fears about my tie rods so I try not to end up at full lock while flexed out off-road anyway, so it hasn't been an issue.

 

[Fordified1]

You'll definitely have to cut the rears off. I only have the slightest rub up front with 1.25" spacers flexed out at full lock. I've been on here long enough to have some residual fears about my tie rods so I try not to end up at full lock while flexed out off-road anyway, so it hasn't been an issue.

Mine isn’t close to hitting the rear. Do you have aftermarket upper control arms by chance? I don’t and because the caster is corrected with the lowers it may have moved the tire forward a little more than one with the caster corrected with aftermarket uppers. My tires measure 36.5”

 

[BigMeatsBronco]

No...I've had the biggest tires for some time 37s...then 40s, now 41x14.50r17...I didn't buy any "kit"!!! Just carefully trimmed.

 

[GI_Jo_Nathan]

What @BigMeatsBronco said. I took his lead and chopped my factory mounts. For other reasons I couldn't run any of the bolt on options, and didn't want to weld on the other option. However I didn't realize that the jks kit comes with brackets for the rear to remove the big plastic piece for more clearance. I know @bigmeetsBronco did a bunch of massaging back there for the big tars. I'm having issues back there and weill have to fab something up, or bite the bullet and buy the metalcloak kit for the rear.

Lots of people have more issues than others, a lot of the 37s are on the small side like the bfgs at around 36/36.5. Some are more aggressive and more square tread and tend to tear things up. Also seems like some suspension flexes more than others and causes issues.

I am running Pro Comp upper control arms, wonder if that could be affecting things for me. My Kenda Klevers seem to run pretty true to size, versus my buddy who has factory arms and bfgs with very minimal rubbing.

 

[BroncoStang]

What @BigMeatsBronco said. I took his lead and chopped my factory mounts. For other reasons I couldn't run any of the bolt on options, and didn't want to weld on the other option. However I didn't realize that the jks kit comes with brackets for the rear to remove the big plastic piece for more clearance. I know @bigmeetsBronco did a bunch of massaging back there for the big tars. I'm having issues back there and weill have to fab something up, or bite the bullet and buy the metalcloak kit for the rear.

Lots of people have more issues than others, a lot of the 37s are on the small side like the bfgs at around 36/36.5. Some are more aggressive and more square tread and tend to tear things up. Also seems like some suspension flexes more than others and causes issues.

I am running Pro Comp upper control arms, wonder if that could be affecting things for me. My Kenda Klevers seem to run pretty true to size, versus my buddy who has factory arms and bfgs with very minimal rubbing.

Honestly that's what I was thinking, I'm going with the Mickey Thompson Baja Boss and 1 inch spacers, I've seen posts on here where some people ended up with minimal rubbing so I was thinking about just cutting and grinding where needed and not going with a kit
I agree those JKS brackets look like they would be nice to have though.

 

[GI_Jo_Nathan]

Honestly that's what I was thinking, I'm going with the Mickey Thompson Baja Boss and 1 inch spacers, I've seen posts on here where some people ended up with minimal rubbing so I was thinking about just cutting and grinding where needed and not going with a kit
I agree those JKS brackets look like they would be nice to have though.

Yeah I believe the Mickey's run pretty true to size, if not maybe a little larger than most. My buddy has them and they're definitely larger than my Kendas. And they're a very Square tread pattern which is what gets you into trouble on those outer lugs rubbing things.

This is what I did based on what Bigmeats did. I picked his brain a little before I attempted it. The main heads up I will give you is that this Mount seems to be under some sort of pressure, so it kept trying to grab my Sawzall blades when I would get about halfway through. Made it sort of a pain, versus just lopping it off and being done with it.

I have my winch plate bolted where the jks kit goes. I also did not like the idea of having my front body mount being bolted on versus the original welded configuration. Just one more thing to in theory be a weak point.

 

[BigMeatsBronco]

Here's mine...good for 40s +

 

[KABQ]

Mine isn’t close to hitting the rear. Do you have aftermarket upper control arms by chance? I don’t and because the caster is corrected with the lowers it may have moved the tire forward a little more than one with the caster corrected with aftermarket uppers. My tires measure 36.5”

I don't, I'm still on stock sasquatch UCAs. Mine rubbed the rear bars pretty badly, especially at lock in reverse.

 

[BroncoStang]

Mine isn’t close to hitting the rear. Do you have aftermarket upper control arms by chance? I don’t and because the caster is corrected with the lowers it may have moved the tire forward a little more than one with the caster corrected with aftermarket uppers. My tires measure 36.5”

No touching the rear at all? Even under flex or full lock? That does seem like a decent gap still. I'm hoping to keep my rear because of my mudflaps use it to mount, if they clear the tires as well, but I guess we'll see. May consider a "smaller" 37" tire now if I can get away with just hacking at the front.

 

[Fordified1]

No touching the rear at all? Even under flex or full lock? That does seem like a decent gap still. I'm hoping to keep my rear because of my mudflaps use it to mount, if they clear the tires as well, but I guess we'll see. May consider a "smaller" 37" tire now if I can get away with just hacking at the front.

Your mileage may vary. Haven’t had it fully flexed yet. We do rock crawl, but haven’t since switching from 35’s to 37’s. Also your wheel offset comes into play. Mine are +12mm. Zero offset or negative offset may very well hit at the rear.

 

[N8do]

Love the feedback! I have 37s and a 17X9 wheel with +12 ready to go on soon.
The 37x12.5 Blackhawk Ridgecrawler RT is measuring 36 even, when non mounted on the wheel.
I'm expecting with only a 1.5 front level, and 1/2 inch rear, to be right in there with little to no rub on this set up.

I appreciate the guidance and pics for trimming the crash bar mounts if necessary.
Thanks @BigMeatsBronco and @GI_Jo_Nathan!

I rather not do a JKS if not needed!

Here is another caveat....did everyone do a Forscan speedo recalibration for the tires to 37??
If not, any issues??

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