flat tow HMMWV

[Ray70]

The 242 does have a pump, the 218 does not. Slow speeds on the back roads you might get get lucky and be ok without pulling the shafts but for the sake of a few minutes it would be well worth your time to pull them. At highway speed it doesn't take long to melt down the aluminum parts of a transmission or T-Case.... ask me how I know... better yet ask the guy who towed my truck with a wheel lift and had to pay to replace the tranny, plus court costs!

 

[Retiredwarhorses]

The 242 does have a pump, the 218 does not. Slow speeds on the back roads you might get get lucky and be ok without pulling the shafts but for the sake of a few minutes it would be well worth your time to pull them. At highway speed it doesn't take long to melt down the aluminum parts of a transmission or T-Case.... ask me how I know... better yet ask the guy who towed my truck with a wheel lift and had to pay to replace the tranny, plus court costs!

Being I have rebuilt my fair share of 218's and 242's, please show me in the TM where the pump is....

 

[Ray70]

When I looked up a parts schematic for a 218 it does not show a pump, but every schematic I see for a 242 does shows a pump, item 24 below.
Each one I looked at says used on Jeep Dodge Hummer etc., so, are they talking civilian Hummer's only? I know there are several different versions of the NP/NV242, does only the AM General HD version not use a pump? I'm not doubting you, just wondering what the differences are between them. I've never worked on a T-Case from a military HMMWV, mostly just civvy 246's and 261's, so I'm just going by the schematics and it sounds like we are talking about 2 different version cases here.

 

[Retiredwarhorses]

I see the pic, but the TM does not refer to anything as a pump. They are just wet sump...not saying it isn't, but just from what I know...either way....the correct method of flat tow has been discussed and I think agreed upon.
its best to disconnect the drive shafts.

 

[ClarkeF]

When the t-case is in neutral the internal pump will not operate which would burn t-case.

That's incorrect. The t-case pump is operated by the rotation of the tailshaft. As long as the tailshaft is spinning the pump is pumping. Now as to flat-towing the 3L80 trannys without a park - I would recommend no - even with the t-case in neutral. The tranny can still spin from parasitic drag and that pump requires the input (engine) be spinning. On the other hand, if you have a 4L80E tranny (four speed with park from the later A2 HMMWV's), put the tranny in park to keep the output from spinning, the t-case in neutral, and flat tow. This is the recommended approach from AM General for their Hummer - which is mechanically identical driveline-wise to the A2 HMMWV's. No way to put the tranny in park? Either let the engine run while you tow it with tranny in neutral and t-case in neutral or the preferred option would be to disconnect the driveshafts from the t-case, secure them well, and tow.

 

[olewhiskey]

5 more minutes disconnecting the rear driveshaft goes a long way regardless.

 

[ClarkeF]

Being I have rebuilt my fair share of 218's and 242's, please show me in the TM where the pump is....

280-24P1, Figure 130, Item 40. Part number 5938674, pump, rotary.
http://www.hummerpartsguy.com/PUMP-ROTARY-TRANSFER-CASE_p_3507.html

Similar rotary pump driven off the tailshaft in the 242AMG. The picture linked above isn't the AMG version of the t-case.

 

[greenjeepster]

I was reflecting on the comment about towing one with the engine running so I attempted it today. Outcome is that the power steering makes it track poorly if the engine is running. It headed one way and I the other and I had to stop and crank the wheel around straight again.

Keep in mind that this thing does not track well behind a full size Suburban to begin with and the power steering just exponentiates the issue.

 

[dilligaf13]

The other issue with towing a running vehicle, especially one with an unknown service history, is that there is no one monitoring the towed vehicle's operation/gauges. It could easily overheat, or lose oil pressure, and what would be an otherwise minor inconvenience could cost you an engine or more. And since it's illegal, in most states, for occupants to ride in a vehicle being towed I concur that pulling the shafts is the second best option, behind trailering/rollbacking.

 

[Milkman357]

I've flat towed my M-1009s several times, easy peasey. I've been looking for info/pictures on the connections for hooking up a towbar to a Hmmvw. Doesn't look like I can use my Home made tow bar ends on the Hmmvw.
Any help or suggestions would be appreciated.

 

[ClarkeF]

Look for a post from me in this forum about seven months ago for pics.

 

[springbok]

Flat Towing a HUMVEE

Wanted to see who else has flat towed a HUMVEE. I towed an M1113 with my Chevy Silverado 1500 once, all I can say is DON'T it pushed the truck around more than once...
Whenever my EUC clears I will be going to get an M998 and was thinking about flat towing it with my M1038.
Anyone ever try that out?
Also just an FYI, it actually tracked worse when we tried flat towing it with it running hoping that having the power steering would help...

 

[Retiredwarhorses]

Personally...what I tell anyone with no experience in flat towing, or towing loads of any sort for that matter is "NO".
flat towing is fine for emergencys, but I would not go long distance...in other words, I would flat tow to get a truck off a base, or to a safer place after a breakdown etc.

I can't tell you the folks who come in my shop who can't use a crescent wrench and want to flat tow an M939 home with there F250.

 

[patracy]

Flat towed my M1038 with a 2012 1500 crew cab 4x4 chevy around 100 or so miles. Driveshafts were disconnected. Make certain the diffs and gearboxes have lube in them. IT was uneventful for the most part. I strapped the wheel into a center position. With sharp turns though, it tried to steer against the turn resulting in some skidding of the truck I was driving. I'd not recommend doing it in the rain for that reason. Also note that with the bodies being aluminum, you're going to need tow lights that you strap down. (I used tie wraps) If it's wired, you'll need extra long cables. If you've never towed a heavy load before, I wouldn't recommend it either. There's no braking from the HMMWV happening. I guess I'd say only do it if you feel the vehicle to be towed is up to it. (Good tires) The tow vehicle weighs as much or more (6K lbs or more). And you're not "green" to trailering and towing. Also I took back roads the entire way.

 

[springbok]

I have towed pretty heavy things before, my Chevy 1500 did fine other than tight turns. We did about 200 miles at 65 mph.
This one is only 1.5 hours away and the main question was should I use the 1500 again or take my other HUMVEE.
I thought about renting the U-Haul but it states to be 1" to narrow..

 

[Retiredwarhorses]

I have towed pretty heavy things before, my Chevy 1500 did fine other than tight turns. We did about 200 miles at 65 mph.
This one is only 1.5 hours away and the main question was should I use the 1500 again or take my other HUMVEE.
I thought about renting the U-Haul but it states to be 1" to narrow..

Flat towing at 65mph?

 

[Retiredwarhorses]

Flat towed my M1038 with a 2012 1500 crew cab 4x4 chevy around 100 or so miles. Driveshafts were disconnected. Make certain the diffs and gearboxes have lube in them. IT was uneventful for the most part. I strapped the wheel into a center position. With sharp turns though, it tried to steer against the turn resulting in some skidding of the truck I was driving. I'd not recommend doing it in the rain for that reason. Also note that with the bodies being aluminum, you're going to need tow lights that you strap down. (I used tie wraps) If it's wired, you'll need extra long cables. If you've never towed a heavy load before, I wouldn't recommend it either. There's no braking from the HMMWV happening. I guess I'd say only do it if you feel the vehicle to be towed is up to it. (Good tires) The tow vehicle weighs as much or more (6K lbs or more). And you're not "green" to trailering and towing. Also I took back roads the entire way.

but you know how to work a Crescent wrench...I say to all newbs who are clueless to flat towing, rent a flat bed trailer.

 

[springbok]

65 mph was fine, Figured the M1113 would take it. I was not driving though...
The M1113 is a bit heavier than an M998 so my truck would probably have less issues. Just trying to decide, take the truck or take the HUMVEE.
If I had easy access to a trailer that it would fit on I would do that..
FYI, Anyone in the Delaware area need a tow bar, once I get this thing back I will sell it off. It is brand new with the feet. Will have only been used once...

 

[olewhiskey]

From friends experience-All Flat Tows M998
F150 4 x4 5.4 towed with OD off. Tracked excellent , 128 miles , all highway 60-65mph, got on road from rest stop forgot to put in D, left in OD. Truck never knew it ran 65mph before noticed. Temps all good.
F250 4x 4 7.3 Auto- 344 miles two trips, as above no issues. All Highway 1st trip Detour on about 111 miles back roads 2nd trip
Suburban LT1500 350 Vortec Auto. Not Again Did not track well, low speeds and back roads required 234 miles, Average speed 38mph. Humvee tracked better over rough roads than smooth.
No trips where executed in rain. All Humvees had proper inflation and very good tires. Drive shafts disconnected. Differentials inspected for fluids, leaks, loose bolts etc..
Uhaul rents a 7.5 trailer , they do not like to rent it for Humvees, the 1038s will barely squeeze onto these, but will.

 

[springbok]

May rent the U-Haul, not like they will know what I am putting on it. Cost is only $58 for the day.
Probably much safer. It would be fun to pull my M998 with my M1038 though, the looks I would get haha