JLTV

[BobS]

Seems like we are re-inventing the wheel. Wasn't there this thing called a "mighty might" somewhere a few decades ago. Seems like we aways go back to basics.

Absolutely. Although underpowered for the role of EFSS prime mover, the size constraints are almost a duplicate of the M422. The main issue of being able to tow the mortar at speed would not be corrected by going back to the "Mighty Mite".

Basic description for those not familiar wit hthe M422: http://www.m38a1.ca/m422.html

Photos: http://www.enter.net/~lbensinger/mitymite.html

Unfortunately, even the M422 (specifically NOT the A1 or A2) would not meet the specs-my PERSONAL OPINION (definately NOT fact) is that the Marine Corps is looking for a return to the MB of WW2, however, the specs for airlift and internal carry in the Osprey even eliminate the MB. If you will excuse the expression, it's 10 lbs. of crap in a 5 lbs bag.

 

[BulletDr]

Tanner and BobS,
You both have raised my curiosity with your familiarity and partial knowledge of the Growler and EFSS. I work for GD-OTS and am on the program, so I feel my knowledge of the product is as good as anyone's. Thanks to BobS for the opinion on Steve Wilson as being the worst kind of investigative reporter. Your comment about his one sided stories are spot-on. He and his wife were fired from Fox 13 here in Tampa some years ago for failing to present both sides of a story...WXYZ Detroit conveniently forgets this in his online bio. And with all due respect to Hackworth's SFTT site (I used to be a technical advisor to Hack before he passed away, in his early web days for all things large caliber ammo related) remeber that portraying SFTT as the champion of the little guy is their schtick. They seem to hate every new piece of hardware and portray all active duty acquisition personnel as evil.
Just to set the record straight about the EFSS and ITV/LSV vehicles....here's the truth. These vehicles have undergone numerous redesigns to get to the current spec-compliant state. The LSV is now oficially the M1161 Light Strike Vehicle. The EFSS system received full rate production status last thursday. That system begins fielding in August. ITV/LSV decision will be in mid-July. Both vehicles did indeed begin their design process as re-bodied MUTT variants offered by American Growler. But that was 3 years ago. Since then, GD has completely redesigned them to meet all the requirements. Am Growler simply didn't have the design sophistication to do it so they now assemble our vehicle design. We met every FMVSS rollover requirement and the MIL-STD-209 J and K requirements for air transport. We use a very low CG and air-ride suspension (adjusts on the fly) to address the narrow body rollover problem successfully. We use a 2.8L Navistar Defense (former International Harvester) turbo diesel tuned for JP8 making 132 bhp married to a GM 4L70 AT and two speed Mopar transx case. The air ride suspension has 3 dash settings for height: 1 is fully deflated on the jounce bumpers for internal in MV22, 2 is road height where we are safety certified to 65mph on improved and unimproved and 3 is high setting giving 13" clearance at mid-body for extreme terrain. Setting 3 interlocks the tranny to only 1st and R gears to prevent rollover. LSV also has joystick rear wheel steering with auto centering momentary button and can only be used in 1st and R. This allows line-up and "crabbing" as the LSV enters the MV22 cause side clearance is tight. Only one part remains on either of these vehicles from the M151. It is the floor headlight dimmer switch! We couldn't find a watertight (for fording) replacement floor dimmer switch so we still use one that was on the old MUTT. All of the newer dimmers are stalk mounted and we didn't want those. So there is the truth! There is one part from the MUTT on the EFSS/ITV/LSV vehicles. Aside from that, these are brand new, state-of-the-art tube/monocoque vehicles with amazing capabilities in a miniscule envelope

 

[BFR]

which mopar tcase?
is that 2.8 a 4cyl?
you may have just created my dream jeep driveline...

 

[BulletDr]

The 2.8L is an I-4. Navistar calls it their Maxxforce D2.8I4 http://maxxforce.com/Application/defense. The bhp and torque ratings they provide here are on commercial diesel. We are tuned to run JP8 which has a lot less energy. We are getting about 235 ft lbs or torque. I'll have to check the transx model and get back. I don't have the info on my desk right now.

This engine is not yet EPA certified in US (undergoing cert right now) so I doubt Navistar can sell it for commercial application

We initially looked at the Jeep Liberty 3.0L diesel from a couple of years back and are glad we didn't select it. The supplier agreement with the Italian co. who makes it has broken down with Chrysler and Liberty owners can't get parts for those even from their dealers

 

[BobS]

The 3.0L is NOT a VM engine-it is a Mercedes POS (lots of issues of maintainability, cannot be rebuilt, other issues like poor durability). Don't blame Chrysler for the issues with VM-thank Daimler-Detroit Diesel owns VM now. The VM worked out quite well in the EU and military versions of the XJ years ago (the 2.8L inline 4). The transfer case is not "Mopar", it is a New Venture Gear NVG241OR IIRC-a former joint venture between GM and Chrysler that is now a seperate company.

For myself, my knowledge of the GD EFSS prime mover was based on a visit to American Growler about issues of the original vehicle, a job offer after a review of the program at GD-OTS in Florida (great guys, but unfortunately, family issues prevented me accepting the offer), and several reviews of TAACOM documents.

Best regards,

Bob

 

[BulletDr]

Bob you are right. I went to our chief design engineer to get straightened out.

The transfer case is a New Process/New Venture/Magna Int'l (latest name) 241OR. I mistakenly said Mopar because I remember when we specified it specifically for its 4:1 low gear (most all others are 2.8:1), it's only current application was for the Rubicon which I associated with Chrysler Jeep. My bad on that.

I also erred when I said we looked at the 3.0 Liberty powertrain. It was in fact the 2.8L and it is the VM Motori engine that we looked at. Chrysler quit selling it in 2006 because US emission requirements changed and the 2.8L didn't meet. This resulted in a dispute between VM and Chrysler, and the result is not only is the engine no longer offered but also there are difficulties in getting spare parts in N America. When we talked to Chrysler about it they said they couldn't offer us that powertrain because it was no longer an "active" product in 2006.

Bottom line is we determined the 2.8L VM was not robust enough to meet our tractive effort requirement. We judged the block to be too light for our application (our LSV weighs 2 tons and carries a 1 ton payload) and more suited for a light duty application like a small passenger car. As our chief engineer said, it would've "pooped" the crank out the back in our tractive effort test.

Hope this clears things up.

 

[BobS]

You are quite correct on the original application for the NVG241OR-it was the Rubicon Jeep. I also agree the VM2.8 would not have been a good choice. It worked very well in the Egyptian YJ's and USMC XJ's, but the Efss would have been a bit too much, assuming you are pulling a minimum of .7 TE. You can't do much better (yet) than the 2.8 Navistar engine. The comparable Cummins (the 3.3B- a Kubota engine originally) is not heavy duty enough either.

As far as "pooped"....I think it might have been more like "shotgunned" the pieces left over....ROFLMAO.

Best regards,

Bob

 

[pmramsey]

The JLTV is here. Has anyone seen one up close and personal?

http://www.lockheedmartin.com/us/products/jltv.html

 

[jpinst]

HMMWV's are not going anywhere. They have too many of them. Many armored versions have only seen the roads on the base. I just got back from Korea and they were driving around M998's that were in pretty good shape....

Do you need a JLTV to ride in around the base in a non hostile environment? These will be exclusively combat trucks, designed for such a purpose, but general logistical trucks are still needed.