Big Trouble on a Big Tire!

[M1075]

Had the first flat on the Oshkosh. It was during a fire, so didn't bother to stop until the fire was out. The beadlock worked great, but the tire was trashed when we changed it. Two of us changed it in the field with basic hand tools and a 3/4" impact.

 

[cranetruck]

Good thing it didn't happen on the road!

We don't see enough pictures of your beautiful truck, how about some close-ups?

 

[rizzo]

ditto

 

[clinto]

Why did it fail in that way (first pic)? Dry rot, overloaded, etc.?

 

[M1075]

I've got several pictures up on my website. If you want to see something in particular, let me know.

The tire blew on a rock. See the hole it made in pic # 2. The CTIS was engaged and the tires were deflated so it left the sidewall a little 'exposed'.

 

[rizzo]

what air pressure does the ctis use deflated?

 

[M1075]

Good question! The CTIS has four settings: Highway, Cross Country, Mud/Sand/Snow, and Emergency. It uses different air pressure for each setting (front and rear) and also engages the necessary differential/axle locks.

Highway - 65psi Front, 75psi Rear
Cross Country - 34psi Front, 38psi Rear
Mud/Sand/Snow - 20psi Front, 23psi Rear
Emergency - 15psi Front, 18psi Rear

 

[cranetruck]

M1075, I have asked this question before, but never received an answer (on other forums also).
You actually have this system and are using it, so if anybody can answer, you should be able to.

Question: How long does it take to cycle the tire pressure from high to low and back to high? What is the capacity of the compressor on the M1075? On a deuce with about 7 gal/min, it would take a long time, perhaps 20 minutes or so, if my calculations are correct.

EDIT: Cubic feet/min not gal/min

Thanks,

 

[M1075]

Bjorn, I'll have to check the manuals to be sure, but your estimate is close. Those 16.00R20 tires take a lot of air! My memory tells me that it is approximately 4 min between each setting during inflation, with the exception of 8-12 minutes to get to Highway. Times are a little quicker airing down or when the RPMs are up. The settings are incremental (i.e. you don't normally go from operating on the highway to an emergency off-road situation or vice versa). I think the compressor is 31CFM.

 

[rizzo]

Good question! The CTIS has four settings: Highway, Cross Country, Mud/Sand/Snow, and Emergency. It uses different air pressure for each setting (front and rear) and also engages the necessary differential/axle locks.

Highway - 65psi Front, 75psi Rear
Cross Country - 34psi Front, 38psi Rear
Mud/Sand/Snow - 20psi Front, 23psi Rear
Emergency - 15psi Front, 18psi Rear

my michelins say 100psi on them????