Hydro-assist necessary for 40s?

[Frank..]

Was planning on running 37s but finding some isn't easy right now. I've had STT Pros on order since June and still no eta. I've considered 37" Trail Grapplers as well but they are also hard to find. Might make the jump to 40s. I know it's not ideal but need something for an upcoming trip. I have the RCV shafts for up front and chromolys for the rear. Also have front truss and gussets and rear truss. Still not ideal and I know the possible consequences of running 40s on dana 44s. Anyways, now that I've got all that out of the way, if I decide to go with 40s, will I also need a hydro-assist for steering or can I get away with stock for now?


Also, if someone has a hookup on 37x12.50r17 STT Pros, DM me please.

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[NoahVD]

You could try this system first. Less expense than a full system
https://www.apexdesignsusa.com/collections/all/products/1-1-steering-boost-kit-jl-jt-compatible

 

[Upsidwn]

I mean, in the rocks with beadlocks and 35s the stock box barely gets by IMO. I’m def looking to go hydro assist before any more real wheeling and especially before I’d consider 37s or bigger.

The apex kit is nice, gives you more power, but doesn’t address snapping sector shafts off. You should be looking to take stress off of your box not putting more to it. I’ve spent the better part of a weekend getting a rig with a snapped sector shaft out of the trails before, I don’t wanna do that again haha

 

[GSLSE21B]

Drill and tap your existing box . Disable esc while off-road to run high speed or shim the stock bypass valve to raise pressure

 

[Moto_21]

I must have a rare box or something, im on 40s and at 12 psi i have had zero issues turning the wheels offroading. Id start with the apex booster though hefore full blown hydro assist. Maybe im just used to the struggle I havent noticed any difference than when i was on 35s

 

[Frank..]

I mean, in the rocks with beadlocks and 35s the stock box barely gets by IMO. I’m def looking to go hydro assist before any more real wheeling and especially before I’d consider 37s or bigger.

The apex kit is nice, gives you more power, but doesn’t address snapping sector shafts off. You should be looking to take stress off of your box not putting more to it. I’ve spent the better part of a weekend getting a rig with a snapped sector shaft out of the trails before, I don’t wanna do that again haha

Thanks for the reply. Would the apex kit with the Yeti sector shaft brace be a good fit for eachother?

 

[hoag4147]

Also, if someone has a hookup on 37x12.50r17 STT Pros, DM me please.

Another option

https://www.jlwranglerforums.com/forum/threads/5-brand-new-38x13-5r17-patagonia-tires.77813/

 

[Big_Lebowski]

IMO yes. I felt like I needed it on 37s with my JKU, so added it. Now on 40s with that Jeep. I used the Red Neck Ram from West Texas Offroad. Works great.

 

[DOOKEY]

What 40's are you finding in stock?

 

[Frank..]

What 40's are you finding in stock?

Trail Grapplers and STT Pros

 

[JustaJL]

Look at BFG KM3 39x13.5x17. They are 37 1/4" tall, drive nice and look badass. Stock steering and have no problem steering this tire. I have done a a bit of crawling through some rocks and so far so good. I see the Apex kit, drilling and tapping the stock box, adding hydro assist in my future.

 

[OBJLU]

I run the 39 KM3's, yeah yeah they're not 39 but neither are the DOT 40's 40. I think they're a great middle ground, noticeably bigger than the Milestar 38's and the traction on the rocks is amazing. I took my rig thru the rubicon and I only needed my lockers a handful of times, less than 5. My opinion they're perfect for the JL.

I’ll be adding the Apex boost sometime in the next couple of weeks, sitting in the garage now

If I go to 40's it's for the looks, not the performance.

 

[J0E]

I mean, in the rocks with beadlocks and 35s the stock box barely gets by IMO. I’m def looking to go hydro assist before any more real wheeling and especially before I’d consider 37s or bigger.

The apex kit is nice, gives you more power, but doesn’t address snapping sector shafts off. You should be looking to take stress off of your box not putting more to it.

I’ve spent the better part of a weekend getting a rig with a snapped sector shaft out of the trails before, I don’t wanna do that again haha

Was that a JK with a snapped sector shaft? I've read it's a much more common problem on the JK that a JL.

Look at BFG KM3 39x13.5x17. They are 37 1/4" tall, drive nice and look badass. Stock steering and have no problem steering this tire. I have done a a bit of crawling through some rocks and so far so good. I see the Apex kit, drilling and tapping the stock box, adding hydro assist in my future.

Did you ever upgrade steering?

I must have a rare box or something, im on 40s and at 12 psi i have had zero issues turning the wheels offroading. Id start with the apex booster though hefore full blown hydro assist. Maybe im just used to the struggle I havent noticed any difference than when i was on 35s

Won't cranking on the steering like an old time rig without power steering risk breaking the sector shaft or another steering component? Just made the jump to 37X12.50R17LT KM3s and now I'm worried I'll break a sector shaft deep off road.

 

[Kreepin1]

Was that a JK with a snapped sector shaft? I've read it's a much more common problem on the JK that a JL.



Did you ever upgrade steering?



Won't cranking on the steering like an old time rig without power steering risk breaking the sector shaft or another steering component? Just made the jump to 37X12.50R17LT KM3s and now I'm worried I'll break a sector shaft deep off road.

I feel this is a bit like asking "can I run 40's on Dana 44's?" The answer is "it depends." Like axle shaft failure a sector shaft is most likely to fail from fatigue. Meaning if you don't thrash it you can get away with it for a long time and possibly never have a failure. So if you keep the offset as close to stock as possible, don't turn on hard surfaces with the front locker engaged and you turn when moving (even if this means making short front/back moves while turning) you'll be fine without hydro assist. If you drive fast in rocks and the tires take a lot of hits then you will eventually break the shaft.

However, hydro assist on the trail is a wonderful thing. Effortless turning. Shift the whole front end away from that rock? No problem. Game changer. On the street it's like the biggest steering damper ever. Completely eliminates death wobble. The only downside is driving fast through the trees the steering can't keep up sometimes which means you flat out have to slow down, there is no "if I turn harder it turns faster" effect.

 

[JustaJL]

Was that a JK with a snapped sector shaft? I've read it's a much more common problem on the JK that a JL.



Did you ever upgrade steering?



Won't cranking on the steering like an old time rig without power steering risk breaking the sector shaft or another steering component? Just made the jump to 37X12.50R17LT KM3s and now I'm worried I'll break a sector shaft deep off road.

Was that a JK with a snapped sector shaft? I've read it's a much more common problem on the JK that a JL.



Did you ever upgrade steering?



Won't cranking on the steering like an old time rig without power steering risk breaking the sector shaft or another steering component? Just made the jump to 37X12.50R17LT KM3s and now I'm worried I'll break a sector shaft deep off road.

I have not upgraded the steering yet. I do see it in my future though. I am going to start with the Apex, then drill and tap the box and install a ram and see how that goes.

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