Why Airing Down Works...

DarbyWalters · **Posted:** Tue Sep 04, 2007 11:54 pm

Luckily I replaced the OEM Slicks with Hercules Terra Trac ATs...and none too soon! It is raining here in San Antonio...all day...and I should have known better but I couldn't help myself. I went DOWN (fairly steep) a back alley that was grass covered with slick mud underneath. The alley dead ends so now I have to negotiate a 180 degree turn and OH YEAH, IT IS NIGHTIME :shock:

I was in Full Time 4WD and started sliding around until I was turned around facing uphill but in a slight ditch and up against (or nearly) a tree and fence. I am getting NO TRACTION but the TC feature is working. If I slid back anymore, I was going to either damage the CRD or the fence. I decide to air down my 40psi tires to 16psi. I can only get to 3 of the four tires but I get it done. While I am in the middle of this process a man and his wife stroll down to see what the "50 year old kid" is up to now. The man owns a Wrangler and says "It looks like you are going to be stuck here all night". I keep airing down and they walk away...back up the hill I need to climb up. Yeah, he didn't bother to offer any help but it didn't bother me in the least.

I finally crawl across the passenger seat and slide into the driver seat. I had already put it in Part Time 4WD before trying to air down, so I am set. I put it in 1st gear (auto) and lightly touch the "diesel pedal". If I slip backwards, I will be FUBUed. The airing down of just the three tires does the trick...all sorts of traction and I drive out past the couple...they can't believe thier eyes :shock:

If you have never aired down, it is a good thing to know. The process "lengthens" your tire like a tank tread and gives you a larger tire patch on the ground. It is not because the tire gets "wider" but instead because the tire tread gets longer. Works great for sand too. Just glad my 4Wheel experience came in handy again.

CRDburnouts · **Posted:** Wed Sep 05, 2007 12:22 am

4wheeling 101, works well on mud but is most noticeable in sand. Beadlocks let you air down to 1 or 2 psi for the most tire surface possible :lol:

wildrussian · **Posted:** Wed Sep 05, 2007 7:15 am

nice to know in case I ever decide to go sliding down a muddy hill in the rain :lol:

dirtykj · **Posted:** Wed Sep 05, 2007 7:25 am

What's the lowest PSI that's still "safe" on MT/R mounted on the Moab rims? I have gone down to 18psi. Has anybody gone much lower?

FreeJeep · **Posted:** Wed Sep 05, 2007 7:53 am

I've had my MTRs down to 12 in the sand with no problems. Wouldn't suggest it if your gona be moving much more than trail speed.

LibertyFever · **Posted:** Wed Sep 05, 2007 8:21 am

I agree that airing down can improve your traction on the trail and there are a lot of opinions as to when you should, how low to you go and why it works.

I've experienced a few problems with airing down. The last time I was out on a trail with my stock KJ aired down to 22 lbs I found myself hitting every small rock on the trail

Time for a lift & bigger tires.

I've also wheeled with a YJ with less than 10 lbs in it's 33's. Great traction but I've lost the bead once on the trail and even managed to get gravel jammed into the bead. Had to remove the tire & clean the bead.

Does anybody have an onboard air system on their KJ? I haven't seen any postings about it.

Oh, one last word. Its kind of a no brainer but I'll say it anyways. Don't drive very far on the highway on underinflated tires. It will be difficult to handle and may damage the tire sidewalls.

BeepBeepJeepJeep · **Posted:** Wed Sep 05, 2007 8:38 am

I can't help but wonder how you would have faired with um... better... tires

DarbyWalters · **Posted:** Wed Sep 05, 2007 10:24 am

On the OEMs I would still be there this morning. On the ATs, walked right up the alley. The tires I have now really clean the tread as they go...worth every penny :wink:

It wouldn't have mattered what tire you had at 40psi...lol...

dirtykj · **Posted:** Wed Sep 05, 2007 10:41 am

DarbyWalters wrote:

It wouldn't have mattered what tire you had at 40psi...lol...

Oh yeah

I tried to see how far I could push the KJ on soft sand, MTR, 44psi in 2WD ... answer: not very far

Jeepjeepster · **Posted:** Wed Sep 05, 2007 11:18 am

40psi is a bit high for the kj. 33-36psi is better suited for the libby, so that could of been against you also.

callaway · **Posted:** Wed Sep 05, 2007 11:53 am

I air down to 15 mainly because that's the lowest my air gauge reads

I was out with some xj's - one guy with 33" BFG AT's air'd down to the mid 20's and wound up with grass/twigs lodged in the bead

4wdParakeet · **Posted:** Wed Sep 05, 2007 12:28 pm

I have gone down to 10psi with my MT/R's and stock wheels. I'm really nervous at that point just for my wheel sensors. I usally stay in the 12 to 15 range though. I'm running a 33x13.5x15 pit bull rocker on my XJ and I plan on going down to 5psi next weekend. Hopefully it holds the bead

Parakeet

DarbyWalters · **Posted:** Wed Sep 05, 2007 12:38 pm

Jeepjeepster wrote:

40psi is a bit high for the kj. 33-36psi is better suited for the libby, so that could of been against you also.

With the CRD I get better tire temps and wear pattern with 40psi front and 38psi rear...it is a bit heavier that a 3.7L.

dog_party · **Posted:** Wed Sep 05, 2007 4:00 pm

I think you should have trail-rashed the unhelpful onlooker that was walking back up the hill. I can't believe he didn't offer any assistance.

DarbyWalters wrote:

With the CRD I get better tire temps and wear pattern with 40psi front and 38psi rear.

Same here.

Rush345 · **Posted:** Wed Sep 05, 2007 4:37 pm

I'm new to off roading only had my '02 Sport for a year. I have yet to take it off road since I haven't any armor other then the stock Engine skid plate and I also know I need some sliders. Just a matter of getting $$$$ together. Anyway would not the best scenario be put bead lockers on for airing down your tires??? I'm ignorant on this subject and just adding more thing on the wish list when I can afford to get set up to go out and play. Ever time I sign on to L.O.S.T. the wish list gets bigger and bigger Go figure :!:

dog_party · **Posted:** Wed Sep 05, 2007 4:54 pm

Bead locks are preferred, but aren't legal for road use in a lot of states (if any).

Green Renegade · **Posted:** Wed Sep 05, 2007 5:16 pm

There are lots of DOT legal bead locks out there now. They are just way too much hassle and maintenance for most people. Beadlocks allow you to air down to around 2psi which is overkill for most situations. You are pretty safe with 15-20 on normal wheels.

Rush345 · **Posted:** Wed Sep 05, 2007 5:23 pm

That is what I love about this forum so many helpful people to help us newbies. Although some have slapped me down for coments but I alway appreciate helpful advise and not making feel like a Dumb stupid :oops:

L.O.S.T. rocks :wink:

dog_party · **Posted:** Wed Sep 05, 2007 5:33 pm

Green Renegade wrote:

There are lots of DOT legal bead locks out there now.

I didn't know that. I thought they were illegal in VA. I'll have to check locally. Although, I agree with you that it's overkill for the majority of situations.

Rush345 wrote:

L.O.S.T. rocks :wink:

I agree Rush! That's what's kept me here so long!!

tjkj2002 · **Posted:** Wed Sep 05, 2007 6:45 pm

dog_party wrote:

Bead locks are preferred, but aren't legal for road use in a lot of states (if any).

There are some out there,Rock Stomper makes some,and so does Hutchison bead locks(oddly they make the Rock Stomper one's to).They are pricy,about $450+ per rim but are alloy to help keep the weight down,also they are double internal bead locks which makes them DOT legal.

Oh and if you can get your hands on a set of military H1 rims they are also double internal beadlocks with a metal/rubber run flat,DOT legal.Bad thing is they are 16.5" rims,steel(very heavy),and very expensive.You can have them recentered though to change the BS to what you want,they come with like 8" BS to clear the geared hubs(portals).

Bothe stlye of the above rims are a 2 piece bolt together rims,not a seperate bolt on bead.

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