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Hummer Central Tire Inflation System - Conversion?

Discussion in 'The Garage' started by BorregoK5, Jul 23, 2002.

  1. BorregoK5

    BorregoK5 1/2 ton status

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    I'm not familiar with the mechanical specifics of the system other than how it acts. Is anyone familiar with any conversions onto the GM straight axles?
     
  2. DieselDan

    DieselDan 1/2 ton status

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    The Hummer setup is very different than a straight axle K5. Hummers (HMMWVs) have a reduction box at each axle. IIRC air is plumbed through the spud shaft. I've only seen a couple of HMMWVs with the CTIS (it's not real popular).

    What you really need to take a look at would be the CTIS off a M35A3, which is rebuilt duece and a half. They have a collar added to the stock axle that plumbs air through the hub. If I get hold of a digital camera I'll be taking some pictures next time I have one apart.
     
  3. Sandman

    Sandman 3/4 ton status Author

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    I thought that the air line connected to the center and rear of the rim on like a sliding o-ring or seal. Might be kind of hard to do without some type of portal axle or something.
     
  4. BorregoK5

    BorregoK5 1/2 ton status

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    Are those Rockwell axles with the CTIS converted onto them on the M35A3? What about failure, is it a leak prone system?
     
  5. Parf

    Parf Registered Member

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    One of the MOG axle shops does this conversion on MOG axles. Dana makes a ctis that hangs down outside the tire on a hose for semis. Not rock friendly.
     
  6. chulisohombre

    chulisohombre 1/2 ton status

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    i just got out of the army last year.i have never seen a hummer with the ctis setup.if they make them the army doesnt use them on their hummers,just the deuce and a halfs.the rim is 2 pieces with a oring between the two and held together by nuts on one side to sinch the 2 together.i dont know if this is what you were looking for?? /forums/images/icons/laugh.gif
     
  7. DieselDan

    DieselDan 1/2 ton status

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    The Army DOES have CTIS available for HMMWVs, <font color="blue"> BUT </font color> like I said it's a rariety (check TM 9-2320-280-20P-2). It must be added as an Modification Work Order. Most unit's don't bother with it, 1) because of the added maintenance, 2) the M998 has plenty of mobility compared to the heavier vehicles that are also deployed.
    AFAIK CTIS is used on the M35A3 ESP, all the FMTV, PLS, M939A2, M918A2? Dump, Super HET, M800 series ESP, and available on the HMMWV.

    All systems utilize a valve arrangment on each wheel to (help) prevent (single wheel) leaks. All except the HMMWV use a electronic controller to limit air pressure/speed; if you drive too fast the system will increase airpressure to the next level. Levels are Highway, Crosscountry, Sand, Emergency, &amp; Runflat. Emergency is the lowest setting and is time limited. Runflat is a mode that checks/fills air continiously (for those bullet holes you don't have time to patch
    /forums/images/icons/wink.gif ). The controller looks at the tire pressures as ONE big air tank and raises/lowers pressure as needed. Individual tire pressure is adjusted by the wheel valve (like a check valve). There is a metal guard at each wheel to protect the valve, very noticable to ID. Every system that I've looked at direct air thru the hub via a manifold that wraps around the axle housing, typically within the brake drum. The exception with portal gearboxes is the HMMWV. The M939A2 series was the first large scale application and they can be prone to leaks usually at a wheel valve or a dump valve. Supposedly the M35A3 ESP Duece doesn't leak as much with better seals (surprising for a retrofit).

    I guess I gotta get some pictures ... /forums/images/icons/ooo.gif
     
  8. kickinasphalt383

    kickinasphalt383 1/2 ton status

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  9. 88K5Jimmy

    88K5Jimmy 1/2 ton status

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    Ok, so I have no idea why there a big interest for hummer wheels? I have seen a lot of talk about it but don't know if they are good/bad?

    Thanks
     
  10. K10ANDYKHAMNIC

    K10ANDYKHAMNIC 1/2 ton status

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    some have beadlocks , and beadlocks are good for 16.5 tires cuz amost the other rims lack and small raised area that 15s and 16s have , ie it lets go of the tire if you air down . hummer rims have lots of backspacing so it would be kinda a pain to run them i think ,cept maybe on a dually axle setup , or put new centers in them or big wheel spacers.
     
  11. chulisohombre

    chulisohombre 1/2 ton status

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    on our deuces half of the ctis was broken so we had to check it manually anyways.i was out at ft irwin.so we usually just got it working well enuf to run every monthly rotation.not much time to keep 300+ vehicles in perfect running condition.if there was a field fix we could perform thats what we did as parts usually did not come in time and the vehicles usually stayed out for 2 weeks at a time.i just have not personally seen hummwv's with ctis equipped hubs.i think it is better not to have on hummvs personally.with the heavy wheeling we always gave them being in the mohave desert i dont think it would have lasted too long.we changed tires almost daily on the scout vehicles.they think they are sheep on some of the stuff they get in and out of.most of our maintenance was on their vehicles.they also tore up the tanks pretty good too.1 engine cost 250,000.we changed at least 5 every rotation.nice to see where some of our tax money goes huh?
     
  12. DieselDan

    DieselDan 1/2 ton status

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    Ya I was out at Ft Irwin last summer. We're a DS Company so we were helping to fix some of that maintenance backlog. Stuff get's pretty tore-up out there, "driven hard and put away wet." Wasn't too inpressed with the NTC for the reasons you mentioned.

    Personally I think CTIS is a goat rope as far as the DOD is concerned. Logistics folks bought it to save money on tire wear. What good is a bigger footprint when you've got open diffs front and back?

    /forums/images/icons/confused.gif
     

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