Do All HMMWV's have geared hubs?

[Augi]

Hi All,

Simple question. I'm starting to do research so I can get into the HMMWV game in the near future. Question pertains to military of course, not civvy.

Thanks,
Augi

 

[Westech]

civy and military are the same running gear. so yes.

 

[Recovry4x4]

You will find some with and some without. All depends on how long it sits at the CAN point and what the other grunts need for parts!

That's an attempt at humor. As Lugnut pointed out, they all originally had geared hubs.

 

[SETOYOTA]

why do you ask? the geared hub is a great piece of engineering

 

[jwaller]

yup, the only real difference in hubs over the years was the upgrade to 12.1k inputs and then the total upgrade to the alpha hub. CTIS was also mixed in between all makes and models.

 

[Augi]

My dad and I are going to buy a vehicle together so we can go drive around the desert when he visits me in California.

He thought they made some without geared hubs but after reading all sorts of forums I have never seen it mentioned. Seeing as all HMMWVs should have them, it makes sense that no one discusses it.

I am also curious about central tire inflation. I saw some people saying how leaky it was and how much it sucked. They also seemed to imply that not all vehicles had it.

And while we are all here, I guess I should ask the 6.2 vs 6.5 turbo question I'm looking at older trucks and most of them seem to have the 6.2. I am shooting for lightweight setup, probably a soft top anyway, so it's not like there will be tons of armor to tote around. Is the 6.2 that much of a disadvantage?

Thanks for the replies!
Augi

 

[SETOYOTA]

IMHO there is no big difference between a NA 6.2 and 6.5. Now the turbo 6.5 is a bit different. If your looking at HMMWVs for sale 99.99% will have a 6.2 in them as most of these will be 85-93 models.

you do have to watch for cylinder wall cracks in early 6.5 blocks

 

[Alredneck]

I had geared hubs on several humvees I have driven! Then some without after a improvised explosive device decide American engineering was overrated! My head still hurts all day everyday because of them!

 

[jwaller]

the ctis on the H1 can have problems, it's more automatic with electronics.

the hmmwv CTIS is all manual, 1 valve and 1 pump. very trouble free, mine only gets turned one once a week to run the air up after it gets cold out. there are only 4 points of friction in the hmmwv and H1 CTIS system and it's at the back of the gear hub, very good rubber seal that I have yet to see leak on any of them.

 

[jesusgatos]

Only difference I know of is that some of them use straight-cut gears and some of them use helical-cut gears, right?

 

[jwaller]

Only difference I know of is that some of them use straight-cut gears and some of them use helical-cut gears, right?

the H1 Alpha is the only one with helical gears, it was done to help try and hold the torque of the duramax.

All other hmmwv's and H1's have straight cut gears.

 

[Stalwart]

But the early HMMWV's had a tendency to loose the driven gear, and wheel assy. at speed. All Civilian ones were updated but AM General had to keep making the defective ones until they managed to get the Mil. Spec. changed.

One 1992 Civilian model owner was driving across Montana on the way home from the Factory and looked up to see a gear and wheel assy depart his truck. He managed to load it into the back of the truck and continued on his way, at a GREATLY reduced speed, in 4 lock to where he could contact the factory for assistance. I bet a 3 wheel Hummer is a strange sight . . .

 

[Ord22]

they all have geared hubs

 

[papakb]

The military has always used the geared hubs in their HMMWVs because of the significant torque multiplication and ground clearance it gives the vehicle. This holds true of the civy H1s but the H2 and H3s are just Chevy trucks. The early hubs had a problem with the axle nuts backing off and the axle working it's way out of the hub but that was corrected by adding a keyed washer pn 5310-01-213-4185 to the axle locking the nut into the hub.


Kurt Lesser

 

[Augi]

Hmmm... that's good to know. Does that retrofit require replacement of the axle or nut?

The military has always used the geared hubs in their HMMWVs because of the significant torque multiplication and ground clearance it gives the vehicle. This holds true of the civy H1s but the H2 and H3s are just Chevy trucks. The early hubs had a problem with the axle nuts backing off and the axle working it's way out of the hub but that was corrected by adding a keyed washer pn 5310-01-213-4185 to the axle locking the nut into the hub.


Kurt Lesser

 

[papakb]

Yes, the axle nut also gets replaced with pn 5310-01-382-5031. Same axle.


This info is in TM 11-2320-280-24P-1 figure 142


Kurt

 

[hummer4x4guy]

In the 10 years of having my humvee i never had an issue with the drive gear falling you. I even reuse my spider washers but use a different tooth. In my opinion if you take care and note of what you are doing you will not have an issue. But I am a big optimistic.
Joel

 

[p3amea6]

I had geared hubs on several humvees I have driven! Then some without after a improvised explosive device decide American engineering was overrated! My head still hurts all day everyday because of them!

Thank you for your service , I hope you have been to the VA

 

[ClarkeF]

the H1 Alpha is the only one with helical gears, it was done to help try and hold the torque of the duramax.

All other hmmwv's and H1's have straight cut gears.

Actually the reason the Alphaused helical cut gears was to reduce noise over the straight-cut gears as well as the backlash. Straight cut gears are superior to helical in strength - but noisy as heck....

 

[jwaller]

Actually the reason the Alphaused helical cut gears was to reduce noise over the straight-cut gears as well as the backlash. Straight cut gears are superior to helical in strength - but noisy as heck....

I'm pretty sure the helical gears are stronger. You get much more surface area when you twist the contact patch.