M939 tire clearance?

[Buffalobwana]

Anyone consider just raising the bed off the frame by using a 4X4 wood spacer on top of the frame instead of the standard 1X installed?

umm, yeah, I wondered the same thing.
http://www.steelsoldiers.com/showth...-when-you-added-16-00-s&p=2011281#post2011281

 

[Buffalobwana]

Bufflowwanna - I asked in another thread - but you may know...
I was told by someone that has and/or works on the 923 & 925 A2's - that said when airing down for 'Sand' on the CTIS the 1600's will rub. I was trying to wrap my head around the notion of how less air increases tire diameter.... unless the increased sidewall buldge rubs?? Do you know?

Hard to believe, but, possibly they expand outward a little? Hard to believe it's a significant amount.

I was told by someone who really knows tires, that you can not air a 16.00 down below 60 and expect to not have a flat the next day. Said they need 80 to keep the beads seated. And that you can't air these big 16.00's down without beadlocks. I trust him because This guy knows tires very well.

 

[98G]

Hard to believe, but, possibly they expand outward a little? Hard to believe it's a significant amount.

I was told by someone who really knows tires, that you can not air a 16.00 down below 60 and expect to not have a flat the next day. Said they need 80 to keep the beads seated. And that you can't air these big 16.00's down without beadlocks. I trust him because This guy knows tires very well.

What's the low pressure setting on the CTIS on the HEMTT series?

I suspect that the answer to that question will invalidate your expert's opinion...

 

[Buffalobwana]

Do tell? (I know you know!) I don't know what the low psi range (sand) is. Do HEMTTs run beadlocks? I have found them in HEMTT rims tires I bought from you. Do they always run them?

I try to soak up as much knowledge and info as I can from guys who have been at this longer than me. It's why I'm on this site. You know me, I pepper you with questions!

 

[Mos68x]

I've done exactly that. ..

View attachment 680129

View attachment 680128

I like how that looks, I'm going to have to space the frame for the ISO up a bit anyways since the cargo bed is reliefed on a couple of the bed frame pieces. I was originally concerned that lifting the "bed" up too high might make it look retarded, but 3" isn't hardly noticeable.

 

[Mos68x]

I don't know what the low psi range (sand) is.

Hwy is 70, X-C is 35, Sand is 25, Emer is 12, Run Flat will dump air into the tires to get you out of a hotspot. This applies to all trucks except the wrecker.

Its in the 9-2320-272-10 TM

 

[Castle Bravo]

What's the low pressure setting on the CTIS on the HEMTT series?

The HEMTT doesn't have CTIS, but the M1070 and M1074/M1075 PLS do and run 16R20s on 20x10 wheels similar to the HEMTT wheel. Some numbers -

M1070 Tire Pressure

Highway - 45 MPH - 75 PSI
Cross Country - 30 MPH - 55 PSI
Mud, Sand, & Snow - 15 MPH - 40 PSI
Emergency - 5 MPH - 30 PSI

M1070 Axle weights

Axle 1 - 17,620 LBS empty, 20,122 LBS loaded (w/46,000 LBS on kingpin)
Axle 2 - 7,291 LBS empty, 22,022 LBS loaded
Axle 3 - 7,050 LBS empty, 21,982 LBS loaded
Axle 4 - 7,030 LBS empty, 21,982 LBS loaded