question about flat towing a 715

[snakeater]

I have a 350 and turbo 400 in my truck with a stock transfer case. I am wondering about the ability to flat tow it behind my deuce if need be to events and such or for maintenance if something happens. Is it safe to tow with the tranny in neutral? I know the transfer case has no neutral persay, but isn't there a middle stick placement that is not realy either2 or 4wd? Or am I relegated to removing the rear driveshaft and adding lockout hubs to the front to flat tow it? Almost had a jeep catch fire on me towing it on a dolly once and don't want that to happen again. Suggestions are appreciated, Snakeater

[scottsmyth]

Ya, not a good idea to put in neutral, you will toast tranny. I have pulled mine by putting transfer case in "neutral" while in 2wd (t-case levers weren't hooked up so it was possible), don't plan on doing it again, a little nerve racking, but it was my only option at the time.

[brute4c]

Selectro hubs up front and pull the rear drive shaft OR make a plate that has the same bolt pattern as the rear axle and pull the rear axles and bolt the plates on...this is what I did. If you just pull the rear drive shaft, you leave the rear diff spinning...with 5.87 gears, thats making heat and it is drag...pulling the rear axles stops that.

As far as the NP200 having a neutral....

If you pull the rearmost lever back to put it in 4wd, then pull the forward lever back, but only halfway you will find thet you can be between hi and low range and if you hit the gas, you go nowhere...like neutral right?

Well, you still are in 4wd, so while you dont get input from the transmission to the tires and rolling the truck will not get tire rotation to get to the transmission...you still have both the front and rear axles connected. If you jack the truck up and spin any tire/wheel, the rest spin....notwithstanding open diffs, you get the point.

If you ever, like I did, need the truck towed, wheels up, this "neutral" position will allow the front tires to rotate as the tow is in progress...though the trans and motor are still, both axles, driveshafts and the tcase are spinning.
Unlock the Selectros and pull the rear axles and the only things turning are the wheel/tires/axle bearings.

[Barrman]

BOOM! You just stepped on a mine in the great internet mine field.

The issue of flat towing a M715 has been debated for as long as the Zone has been around and probably as long as the M715 has been around. You already got the answer about your 400 and towing. You were also told several ways to "make it work."

However, you haven't been told about the many cases of overheated front bearings, overheated up to on fire front brakes, messed up steering boxes and at least one case I know of where the rear bearings failed allowing a rear tire spinning on the axle shaft to walk out far enough for the driver of the M35 pulling it to see in the mirror.

Yes, I also know of some successful flat tows. But, the horror stories are more plentiful. Add in the fact that nowhere is there anything in the manuals about how to flat tow a M715. You have a M35 and the -10 tells you how to flat tow and what to do. Not so with these trucks. Then you have to find that funky very expensive adaptor unless you build your own.

It is your truck, so do what you want. My personal thoughts are that unless you are being pulled at low speed back to a place to work on the truck. Don't flat tow it. Build a reciever hitch for the M35 and trailer the M715 if you are going more than 20 miles or so on the highway. Not trying to tell you what to do. Just my thinking.

[brute4c]

Dont know about the overheated front bearings, except mine during the brake fire, but I could have missed that part...

The rest, dead on.

The steering needs to be disconnected or the stock manual box will wear out quickly...it doesnt like input from the tires, just from the steering wheel to the tire.

The brakes do tend to grab and can cause a catastrophe...been there! Even members that are aware of this have backed their brakes off, a lot, and still had troubles with the brakes getting very hot and having to be backed off a ton more.

For the rear, in the plates I made to replace the axle shaft, I put a pipe plug in the middle of the plate that can be removed as gas stops so gear oil can be squirted in to lube the outer bearings to prevent trouble...the front brakes grabbed and burned up less than 100 miles from home so I cant tell you how effective that would be on a longer trip.


I do concur with Barrman that the M715 does not seem to want to be towed any great distance in this configuration and that the military does not have any documentaion for doing this like is does for the other vehicles that do respond well to flat towing.

Flat tow is 20-25 miles...might be alright if everything is setup as listed in the thread...still would make me worry to do it again...

[Barrman]

Dave had his bearings and brakes get hot going to Colorado last summer. I don't remember if his fronts gave him trouble back in '05 for the Texas FE.

[brute4c]

I knew his brakes got hot...missed the bearing part...my bad.

[snakeater]

I have a trailer large enough for the 715, but my m-35 is bobbed with 53" michelins. I have to drop a long way to get it low enough to hook it to my trailer. I wonder about the stability of such a rig. If I flat tow the 715 it will most likely be less than miles for everything else i will trailer it behind my tow vehicle. Then hae someone drive the m-35 if needed. Snakeater

[Barrman]

I see your point about the drop. I have one of those 6" solid drop hitches on my M35 with the receiver snugged up right below the pintle. My trailer is still tilted up some. Look at a 5 ton and see how they have the dropped pintle. Maybe something like that with a receiver below it would work?

Here is part of the flat towing story I left out. I you look at two M35's hooked together, the tow bar is angled down just a hair to the front truck. All of the bad M715 flat towing experiences had the tow bar severely angled down to the pulling truck. As in 30 degrees or more. This by nature causes down force on the truck being pulled anytime the towing truck pulls forward. Could that down force be the cause of the bearing/steering problems with the front end?

Hooking a tow bar to a M35 will be the other way. The M35 will actually apply some lifting force to the front of the M715. I have never heard of any bad front end experience when pulling with a M35.

Some Saturday when you wake up wondering what you are going to do. Hook up to the M715 and take the M35 down the road at highway speeds for 20 miles. Stop and use an infrared thermometer to check all 14 tires and 8 bearings/brakes. I would imagine the front M715 tire tread will be hotter than all the other tires. See if the bearings or brakes on the M715 front are the hottest as well. If not, Go another 10 miles or so from the house and then make a 30 mile speed run home checking everything again at home.

It would probably be safer to do this when it is cool outside. So, any high heat build up will actually go away once you stop compared to summer where it just gets miserable.

Oh, if you have the solid state blinker on your M715. You can run a trailer plug from the M35 to the trailer plug on the back of the M715. Unscrew the M715 blinker arm plug on the steering column and then all the blinkers, running lights and stop lights on the M715 will work off the M35.