M1028A3 Towing Capacity

[hooyahdiver]

From what I've read, there isn't an "in-writing" answer (The Army limitation is BS) but everybody has an opinion. Here goes... my 1028A3 is the 8ft bed, dual rear wheel configuration. I think it has 35,500 miles but there's no 1XX,XXX so it may be more. Doubt it though. It has a turbo 400 tranny, NP 208 transfer case and of course the naturally aspirated 6.2L diesel. The DANA 70 rear end is geared either 4.56 or 4.88 to 1 depending on the reference used. I just ordered a CURT class 4 hitch based off what another steelsoldier member did to his truck. Of course it'll have to be modded to fit. I'm also installing a trailer brake controller to pull my 14' utility trailer. Later I plan to either get a Gear Vendor Overdrive or put in a tranny that has one (4L80E).

Anyway, with the configuration I have now, I think this thing should pull 12,000-15,000 lbs with a class 4 hitch and even more with a gooseneck. I don't care about the whole 6.2L is gutless arguement. The only other thing I can think of that needs to be done is possibly install a transmission oil cooler if there's not already one.

I'd really appreciate real experience based opinions over the notional ones. I have a lot of confidence in this truck based off how stout it is and what I've read but there must be a reason the tow ratings are so low the M1008's and 1009's. I can't find much info on mine. Thanks ahead. You guys and this site have already helped me out tremendously.

 

[hovenga67]

I just pulled my extra m1008 on my 4000lbs car trailer to girlfriends moms to store it. With the trailer and load that should have weighed 10,000 plus the truck and my junk in it 6000 equals 16000. It pulled fine but not real fast. I could do 55 easily except for when I hit a hill. Hopefully when I put the turbo on it will help that. I wasn't using a brake controller because I don't have it hooked up yet. Also I only have front brakes because my proportioning valve is off because of my lift. Mine is not a dually like yours either.
Brent

 

[NDT]

Today, with a tired M1008 I was pulling around a 8000 lb mini excavator on a bumper pull equipment trailer that weighs around 4000 lb. With this weight, you appreciate the stock gearing.

 

[Stonepicker1]

Hey, hooyahdriver.
Welcome to SS. Below you will see my M1028 pulling my M1023A2's. I trailered them from Michigan to South Florida at 65 mph(35 to 45 mph up the big hills in Kentucky) I didn't have any problems at all.
I have a gooseneck in the M1028 and I hauled a forklift that weight 14,000 lbs and it pulled fine. Slow on take off, but pulled fine. I have a electic brake controler installed(a must have)

 

[jdemaris]

It has a turbo 400 tranny, NP 208 transfer case and of course the naturally aspirated 6.2L diesel. The DANA 70 rear end is geared either 4.56 or 4.88 to 1 depending on the reference used.

Anyway, with the configuration I have now, I think this thing should pull 12,000-15,000 lbs with a class 4 hitch and even more with a gooseneck. I don't care about the whole 6.2L is gutless arguement.

I understand your sentiments about not wanting to hear the "gutless" argument. It IS an issue though. Because of the severe lack of power, it's very easy to overheat and crack the heads if you're not willing to back off the throttle when the truck won't reach the speed you want it to. That may mean when getting half way up a long grade, you might have to pull off to the side for a cool down period, before finishing the climb. I've had to do it many times over the years. Also pre 1992 6.2s when worked hard at high RPMs tend to get cracked blocks at the main bearing webs. Very common problem. Not often seen in military rigs simply because they don't get the high speed miles on them.

I know you're going to hear claims to the contrary - so you're going to have to make your own decisions. I've been driving and towing with 6.2s since they first came out done pretty well with them. I also worked in several diesel shops fixing or replacing them. I've had many trucks with TH400s and 4.56 gears, and I would never consider pulling more then 8,000 lbs. behind me on a long trip at highway speeds unless it was relatively flat. No problem with the durability of the drivestain, just the light-duty aspect of the engine. It has weak main bearing webs, a cast iron crankshaft (most diesels use forged), light head castings (if original), and a short-stroke relative to bore.

Keep in mind that that when the 6.2 first came out, it was the lightest and cheapest diesel engine around (for its size). 150 horse and 240 lbs. of torque is not much. A few companies that made full-size Class A 14,000 lb. motorhomes tried the 6.2 diesel. It was a miserable failure. Many had ruined engines by 30K miles and got repowered with Cummins 3.9s or Isuzu 3.9s. Many big bread-vans also used them, and many of those also got Cummins repower.

So, you've got an engine that was intended to be a power equivalent to a 305 c.i. gas engine and not built for HD use. Why would you expect it perform well in pulling such a heavy trailer under sustained use? The highway speed need is the main killer. Just about anything can pull any weight if geared low enough and speed does not matter.

You said you didn't want "notional" input here, and that's not what I'm doing. Like I've said, I've been using 6.2s since they first came out. I'm not an "anti-6.2" person. I have over 20 right now. They offer cheap power and reasonable fuel economy when not worked extremely hard. But when pushed beyond their reasonble limits and run steadily over 2500 RPM, not so good, and fuel mileage drops like a rock. 6.2 gets peak fuel efficiency at 2000 RPM.

Also about the overdrive. The Gear Vendors won't eliminate the torque-converter slip-loss that can climb to 15-20%. An OD trans with a lockup converter is a better idea if you are trying to improve efficiency. Don't expect to be towing much in OD though.

And again, I'm talking about towing at highway speeds, in areas with hills, and sometimes altitudes well over 1000 feet. I do most of my towing at 1500 - 2000 feet. 6.2 really gets bads if you ever have to use it in high country, like 5000 ' and higher. It loses 1 % of it's power for every 328 feet abouve sea level. My son took one of mine home with him to Colorado near Denver, and had to put a turbo on it to make it tolerable to drive.

 

[hooyahdiver]

Thanks for the input. The point you make just validates everything I've been reading about the 6.2L. I'm a little disappointed since I bought this truck to tow with (and because it's cool). I've always wanted a CUCV so it's not a loss. I'm still going to tow my trailer with it. I'll just have to take it easy. My unit leaves for Afghanistan again in March so I'll have a year to decide what to do with it. My plan was to buy a new 3/4 ton after this rotation until I found this thing. I thought it was the ticket. Maybe it still is. Thanks again.

 

[4bogginchevys]

I really hope I dont get booo'd of this site.......I like my 6.2 and have already found most of the pro's and cons of having one, it is a cool truck (100 and is less common than normal just because of the 6.2.............I'm going 454 Chevy in this thing when the 6.2 dies

 

[POOR WHITE BOY]

454 - easy swap

 

[jimmy-90]

I've been looking into the 5.9cummins/allison swap myself...So I can finally get my M1028 to tow with authority.

 

[jdemaris]

I've been looking into the 5.9cummins/allison swap myself...So I can finally get my M1028 to tow with authority.

The Cummins turbo 3.9 liter engine makes a great swap. It has more power and torque then the 6.2 and much better fuel mileage. It's a easier fit since it's only four cylinders, and . . . you can buy the parts so it's a bolt in swap. Cummins made special repower kits with adapter housings to replace 6.2 diesels in big bread vans. A CUCV Blazer, if geared right can get 26-28 MPG instead of the usual 16-21 MPG with a 6.2.

I do all my towing with a turbo, intercooled 5.9 Cummins and it's an amazing low-end torque engine. If I was doing a swap into a shorter Blazer chasis though, I'd pick the 3.9.

And, I'm not bad-mouthing 6.2s. I like them fine for what they are. Light dury cheap diesels never meant for severe use. And parts are dirt cheap when compared to Cummins engines. I can buy good running 6.2s for $100-$200. Good running Cummin? Usually $1500 - $2500.

 

[BKubu]

Rather than modifying your CUCVs, perhaps, it makes more sense to buy another vehicle that will do what you want. Basically, you are taking a square peg and cutting off the edges to fit into a round hole. There is nothing wrong with swapping in a better motor or transmission, or adding an after market tranny cooler, but you might be better off finding an early 90s Dodge pickup with a 5.9 Cummins already in it.

 

[dstang97]

Hey, hooyahdriver.
Welcome to SS. Below you will see my M1028 pulling my M1023A2's. I trailered them from Michigan to South Florida at 65 mph(35 to 45 mph up the big hills in Kentucky) I didn't have any problems at all.
I have a gooseneck in the M1028 and I hauled a forklift that weight 14,000 lbs and it pulled fine. Slow on take off, but pulled fine. I have a electic brake controler installed(a must have)

what size trailer is that (16')?

 

[powerhouseduece]

Rather than modifying your CUCVs, perhaps, it makes more sense to buy another vehicle that will do what you want. Basically, you are taking a square peg and cutting off the edges to fit into a round hole. There is nothing wrong with swapping in a better motor or transmission, or adding an after market tranny cooler, but you might be better off finding an early 90s Dodge pickup with a 5.9 Cummins already in it.

Where is the fun in that? There ain't nothing wrong with a 600+hp 5.9 in a M1028, but the 3.9 is still a little small for the dually IMO. The 3.9's are better off in the m1009's. I really really wish Chevy got the Cummins contract!

 

[Croatan_Kid]

The Cummins swap is well worth it! I'd ditch the Allison trans idea though, too expensive (trans & controller can be upwards of 8,000 bucks, plus the adapters to make it bolt together). I'd run a 47RH or something just to make the swap easier.


If I ever do it again, I'm going to build it with an automatic. Probably a 47RH and a 241 DHD and maybe some 35s. I love my current setup, just wish I could grab another gear, even with the NV4500.


Oh and the 4BT are actually harder to swap in because of the motor mount position. 6BTs fit in there perfect, almost like they were meant to be there!

 

[RobM36A2]

Sorry to hijack this topic, but cant find it elsewhere..
What is the max. rated towing capacity of an M1028? This is needed to keep my pulling weights registered when I go register mine as a truck.
Now i can legally tow 2722kg, but when I register to truck, they want Original factory specs..

Thank you, from The Netherlands.

 

[scottladdy]

Sorry to hijack this topic, but cant find it elsewhere..
What is the max. rated towing capacity of an M1028? This is needed to keep my pulling weights registered when I go register mine as a truck.
Now i can legally tow 2722kg, but when I register to truck, they want Original factory specs..

Thank you, from The Netherlands.

Right out of the -10 page 2-57:

2-14. TOW A TRAILER/AIRCRAFT
a. Towing Capacities of CUCV Models.

(1) M1009. Equipped to tow M416 Series 1/4 ton trailers with maximum towed load of 1200 pounds for both cross-country and highway travel. Load on tongue should not exceed 100 pounds.

(2) MA1008, M1008A1, M1028, M1028A1, M1028A2, and M1028A3, Equipped to tow M101 Series 3/4 ton trailers with maximum towed load of 3100 lbs. Load on tongue should not exceed 300 lbs.

Hope this helps.

 

[MarcusOReallyus]

(2) MA1008, M1008A1, M1028, M1028A1, M1028A2, and M1028A3, Equipped to tow M101 Series 3/4 ton trailers with maximum towed load of 3100 lbs. Load on tongue should not exceed 300 lbs.

That would be funny if it weren't so pathetically ridiculous. My Jeep Cherokee is factory rated to tow more than that. And has, too, with my M101A1 behind it.

 

[Skinny]

Rather than modifying your CUCVs, perhaps, it makes more sense to buy another vehicle that will do what you want. Basically, you are taking a square peg and cutting off the edges to fit into a round hole. There is nothing wrong with swapping in a better motor or transmission, or adding an after market tranny cooler, but you might be better off finding an early 90s Dodge pickup with a 5.9 Cummins already in it.

This is true but I've been looking on ebay and it seems anything with a 12v Cummins is 5 digits minimum. Of course we are not talking about some rust bucket. They are getting more scarce and pricey as time goes on.

 

[RobM36A2]

The problem overhere is, only factory papers are accepted, and the pintle hook is kinda illegal here..
There is a normal ball fabricated on the bumper.

Here is what the DMV or what it's called here wants to know:
Tow rating for the M1028, Original papers from factory only. (scan might be ok)
A construction drawing of the ball hitch mounting and calculation of what the maximun load is. (maybe able to find someone for this)
Max tow rating of the ball hitch. (Has an id plate, so this is no problem.)

 

[hooyahdiver]

Well put...

I agree with you whole-heartedly. Thanks for the input.