Towing With My Mj

[thejim42]

I'm Curious as to what modifications i can do to my 1988 MJ to be able to trailer my 1973 ford mustang Mach 1 convertible. I'm pretty sure it won't tow it stock but is there anything i can do to increase towing ability. 4.0, 5speed, 2wd with the factory hitch. The truck will soon go under a 4x4 conversion so i figure now is the time to do upgrading since it will be all apart anyway. I plan on using wj front and rear axles a 231 t-case, id like to keep the 5 speed, but I'm looking for advice on what parts and mods to use. The car I'm pulling has a curb weight of about 3500lbs, don't have a trailer yet so can't give a weight on it but it WILL have electric trailer brakes and the truck is all ready accommodated for that. 

[ftpiercecracker1]

Gear change and a set of MJ metric ton springs, dual diaphram brake booster, probably upgrade your brakes in general. If you don't already, you absolutely need to build/buy a proper hitch receiver. The 4.0 is a pretty torquey motor, but if you want some real muscle you could think about building a stroker for it. 

[Biotex]

I'd want four wheel disc brakes in addition to what ^^^He said.

I don't think the problem will be moving, rather stopping that much weight reliably. Some meaty tires and put about 750 to 1000 pounds of tongue weight on the truck so that your rear tires don't skid when braking.

 

Towing is one of the main reasons I'm swapping in a Ford 8.8 disc brake axle.

[johnj92131]

Factory tow package is Automatic Transmission, heavy duty trans cooler, 4.0 Also calls for an weight distributng hitch. 

 

Biotex is right, stopping will be the real problem.  The Dana 44 had/has wider brakes than standard.  Stil, it is no fun going down a hill with a 4500 trailer pushing you when you are trying to stop.

[thejim42]

well i was going to put WJ axles on it for the bigger brakes and the fact that wj's have 4 wheel disc. i was also going to do the WJ brake booster and master cylinder conversion. Is there a manual transmission that will handle the load and be a direct swap?

[thejim42]

I'm not as worried about stopping as i am about the trucks ability to tow

[64 Cheyenne]

I'm not as worried about stopping as i am about the trucks ability to tow

 

:rotf:

 

Seriously, you are overtaxing the truck pulling a car and trailer.

You need a biger truck to do it safely.

 

If I had too... 4 wheel disks, big booster, trailer brakes...

 

and here is the important part, trailer weight and tongue weight won't do a damn bit of good if the tractor is too light

it can get away from you real easy no matter how much brakes you got.

You need more weight IN THE TRUCK to keep control of the trailer, say another 500 lbs or more

or like I said "you would be better off with a bigger truck"

[thejim42]

even with the trailer having brakes?

[Oddmodman]

Definitely need some weight in the bed. A 4500 lb load will easily 'wag the tail of the dog' as it were, even if Jeep rated their MJs at 5000 lbs towing capacity from the factory. Maybe the LWB can do more? 

[Eagle]

Is there a manual transmission that will handle the load and be a direct swap?

 

No.l

 

What factory hitch do you have? The only hitch I know of that came from the factory on MJs was the hitch bumper, and that's not nearly strong enough to be towing a 3500 pound car on a trailer that's going to add another 1500 to 2000 pounds.

[thejim42]

class III receiver...it may not be factory.

[64 Cheyenne]

Pulled a minivan on a car dolly about 40 miles.

Definately should have had some extra weight in the bed of the truck.

At one point was going about 65 mph and nearly started waggin the dog

scared $#!& outa me....

[johnj92131]

even with the trailer having brakes?

YES, even with the trailer having brakes! 

[thejim42]

and all the brake upgrading I'm going to do with WJ axles and brakes and a WJ brake booster and master cylinder?

[tleed]

I once tried to tow a 1955 Chrysler C300 on a trailer with a 1983 full size Grand Wagoneer. Couldn't get over 45 mph without really bad swaying. Like fishtail, end-swapping swaying. Problem with my Wagoneer was the factory springs were tuned to "luxury", and over time they sagged to the point of being spooky towing such a load. I added a leaf to each leaf pack, and the transformation was night & day. Later towed the same car at 75 mph down the interstate, straight & solid as a rock. I know your question is really about stopping, but brakes aren't very important when your front end is heading west, your tail end is heading east, and your tires are sliding sideways across the pavement. I once noticed a big GM 4-door sedan that had been towing a travel trailer down a hill The rig captured my attention because when I saw it the back of the car was up in the air because the trailer had flipped on it's side coming down the hill. That was a heavy trailer "pushing" a car to the point of making it sway & flip.

 

So add me to those suggesting that you're really maxing out this rig. My 16' flatbed car carrier is 1600 lbs. empty. If you're gonna do this, make sure you have a weight distributing hitch, a separate sway control damper, working trailer brakes, etc. Heavier springs would be helpful, too.

 

By the way, I just bought a Draw-Tite 2" receiver hitch last night. It's a used out-of-production item. The sticker on it says the max weight rating is 5000 lbs. WITH a weight distributing hitch. That wouldn't give you much room to work with.

[BootsNTrucks]

Since you're already adding a transfer case and such might wana look at replacing the BA 10 with an AX-15. If you look around on Craigslist you'll probably be able to find an AX-15 and 231 as a unit that somebody pulled. Also correct me if I'm wrong but doesn't an MJ weigh in around as much as the Mustang? Sounds like I'm be tempted to run out and buy a beater full-size.

[Jeep Driver]

Weight distribution is done ON the trailer.

Weight distributing hitches are for trailers with fixed loads.......such as travel trailers.

 

Trailer brakes should do about 70% of the braking......the trailer pulls the truck to a stop.

 

ClassIII with a gross of 5000lbs and a tongue weight of 500lbs.....you are taking it to it's limit......however, know that they are under rated. I'd build one.....I have and I trust mine over a 'factory' ClassIII......used every bolt hole available and do not rely on the factory bumper at all.

 

 

The MJ would not be first choice and I would not pull 5K on the interstate.

[benjy_26]

and all the brake upgrading I'm going to do with WJ axles and brakes and a WJ brake booster and master cylinder?

All the brake upgrades in the world won't be able to break the laws of physics, man. Mass is mass. What you're doing is akin to a flyweight boxer roiding up so he can go beat up on a heavyweight. Maybe he'll be able to do it, but most likely Iron Mike is going to bite his ear off and eat his children. ("All praise be to Allah!" lol). I towed a Suburban on a dolly once with my ZJ. Only about 6 miles on side streets. Even with a stroker, 4 wheel discs, upgraded pads and rotors (not taking anything away from EBC... their stuff rocks!), OME coils and Biksteins all around, it was pretty scary. I could pull the load VERY easily, but when it came time to stop.... well, I definately felt like the load was pushing me around. It's not fun, man. If you want to tow and do it safely and sell, check out dealerships in your area that specialize in used fleet vehicles. I've seen (admittedly high mileage) gas powered Silverado 2500HD's with an allison/6.0 combo go for under 3 grand if you stick to the basic white exterior/ rubber interior, single cab, 2wd long bed configuration.

[Incommando]

 

and all the brake upgrading I'm going to do with WJ axles and brakes and a WJ brake booster and master cylinder?

All the brake upgrades in the world won't be able to break the laws of physics, man. Mass is mass. What you're doing is akin to a flyweight boxer roiding up so he can go beat up on a heavyweight. Maybe he'll be able to do it, but most likely Iron Mike is going to bite his ear off and eat his children. ("All praise be to Allah!" lol). I towed a Suburban on a dolly once with my ZJ. Only about 6 miles on side streets. Even with a stroker, 4 wheel discs, upgraded pads and rotors (not taking anything away from EBC... their stuff rocks!), OME coils and Biksteins all around, it was pretty scary. I could pull the load VERY easily, but when it came time to stop.... well, I definately felt like the load was pushing me around. It's not fun, man. If you want to tow and do it safely and sell, check out dealerships in your area that specialize in used fleet vehicles. I've seen (admittedly high mileage) gas powered Silverado 2500HD's with an allison/6.0 combo go for under 3 grand if you stick to the basic white exterior/ rubber interior, single cab, 2wd long bed configuration.

 

Not true. Can you really tell me that the new CTD Ram 3500 that can tow 30,000 pounds weighs 30,000 pounds or more itself? Absolutely not. The truck weighs about 8,000 pounds. Does a semi tractor weigh 80,000 pounds? If your hypothesis about mass alone were true than no vehicle could tow more than its curb weight.

 

From the factory an MJ with the tow package (tranny cooler/AW4/D44 rear) with a class three receiver hitch installed could tow 5,000 pounds per the factory manual for my '88. See? Even the factory approved it to tow more than its curb weight. Without the tow package the max. trailer weight was 3,500 pounds. ( greater than the average curb weight,too.)  I have the manual buried in storage and only noted the stats for an AW4 as that is what I had.It is possibly that the stick had a 2,500 # tow rating but I am not sure.

 

From my experience I would not tow 5,000 pounds with an MJ  without these things:

 

1. the master cyl. upgrade (WJ or XJ dual diaphragm)

 

2. rear disc brakes if I didn't have a D44 or similar axle with larger brakes than a D35. (many 1/5 ton full-sized tricks used a D44       or equivalent rear and drum brakes)

 

3. upgrade to open cooling system if towing for any distance. (although I never experienced cooling issues with the factory closed     system)

 

4 Stiffer springs and/or helper shocks

 

5. AW4 with a tranny cooler (preferred) or at least an AX15 with a new or HD clutch.

 

6. receiver hitch (with sway control if possible)

 

7. trailer brakes

 

8. 3.55 or better rear gears especially with a stick

 

On my factory-D44 equipped '88 withan AW4,tranny cooler, an aftermarket receiver hitch, and trailer brakes I towed a 12' dual axle solid wood floored landscaping tralier with two riding mowers and other equipment on it with no drama. I never weighed it. It was fine except that emergency braking could get interesting but I was using the stock booster. Such emergency braking issues are pretty common with most towing set-ups that approach or exceed the curb weight of the tow vehicle anyway. Pull in front of a semi to prove this. The '88 truck did have a long add-a-leaf and I don't think that most of our 22 + year old rear springs are still up to not only the weight bearing but the control of the side-to-side motions.

[jimoshel]

I once pulled a '86XJ 40 miles on a 1200lb 20ft bed two axle trailer with a '87MJ 2.5, 4speed. 8 miles of that was on the interstate. It was not by choice. Had no trouble but I took it very easy. No weight in the bed but it would have helped. I pulled '91 Grand Cherokee on a tow dolly 35 miles, 30 of it on the interstate, with a 1990 MJ, 4.0, AX15, No brakes on the Dolly and ti would have helped. Unless it's very light weight VW bug or less, I would not use a tow bar with a MJ under any circumstances. Both instances cited above were with the factory bumper mount. A receiver type would have certainly helped.MJ can be used to tow with but use every advantage you can and just be careful.

[Incommando]

MJ can be used to tow with but use every advantage you can and just be careful.

troof

 

 

 

FWIW Westin/Fey states that their MJ bumper has a tow rating of 350/3,500. That matches the factory max towing capacity without a receiver hitch. 

[benjy_26]

 

 

and all the brake upgrading I'm going to do with WJ axles and brakes and a WJ brake booster and master cylinder?

 

All the brake upgrades in the world won't be able to break the laws of physics, man. Mass is mass. What you're doing is akin to a flyweight boxer roiding up so he can go beat up on a heavyweight. Maybe he'll be able to do it, but most likely Iron Mike is going to bite his ear off and eat his children. ("All praise be to Allah!" lol). I towed a Suburban on a dolly once with my ZJ. Only about 6 miles on side streets. Even with a stroker, 4 wheel discs, upgraded pads and rotors (not taking anything away from EBC... their stuff rocks!), OME coils and Biksteins all around, it was pretty scary. I could pull the load VERY easily, but when it came time to stop.... well, I definately felt like the load was pushing me around. It's not fun, man. If you want to tow and do it safely and sell, check out dealerships in your area that specialize in used fleet vehicles. I've seen (admittedly high mileage) gas powered Silverado 2500HD's with an allison/6.0 combo go for under 3 grand if you stick to the basic white exterior/ rubber interior, single cab, 2wd long bed configuration.

Not true. Can you really tell me that the new CTD Ram 3500 that can tow 30,000 pounds weighs 30,000 pounds or more itself? Absolutely not. The truck weighs about 8,000 pounds. Does a semi tractor weigh 80,000 pounds? If your hypothesis about mass alone were true than no vehicle could tow more than its curb weight.

 

From the factory an MJ with the tow package (tranny cooler/AW4/D44 rear) with a class three receiver hitch installed could tow 5,000 pounds per the factory manual for my '88. See? Even the factory approved it to tow more than its curb weight. Without the tow package the max. trailer weight was 3,500 pounds. ( greater than the average curb weight,too.)  I have the manual buried in storage and only noted the stats for an AW4 as that is what I had.It is possibly that the stick had a 2,500 # tow rating but I am not sure.

 

From my experience I would not tow 5,000 pounds with an MJ  without these things:

 

1. the master cyl. upgrade (WJ or XJ dual diaphragm)

 

2. rear disc brakes if I didn't have a D44 or similar axle with larger brakes than a D35. (many 1/5 ton full-sized tricks used a D44       or equivalent rear and drum brakes)

 

3. upgrade to open cooling system if towing for any distance. (although I never experienced cooling issues with the factory closed     system)

 

4 Stiffer springs and/or helper shocks

 

5. AW4 with a tranny cooler (preferred) or at least an AX15 with a new or HD clutch.

 

6. receiver hitch (with sway control if possible)

 

7. trailer brakes

 

8. 3.55 or better rear gears especially with a stick

 

On my factory-D44 equipped '88 withan AW4,tranny cooler, an aftermarket receiver hitch, and trailer brakes I towed a 12' dual axle solid wood floored landscaping tralier with two riding mowers and other equipment on it with no drama. I never weighed it. It was fine except that emergency braking could get interesting but I was using the stock booster. Such emergency braking issues are pretty common with most towing set-ups that approach or exceed the curb weight of the tow vehicle anyway. Pull in front of a semi to prove this. The '88 truck did have a long add-a-leaf and I don't think that most of our 22 + year old rear springs are still up to not only the weight bearing but the control of the side-to-side motions.

Fine. I oversimplified. Mea culpa. I should have said p=m•v is p=m•v. I'm not 100% sure that manufacturers use this formula to calculate tow ratings, but I'm sure it plays a part. So... assuming that we're working with nice, round #'s, the tires and thr road conditions as well as the environmental conditions cooperate and all the weight is distributed equally, a MJ with a loaded car trailer as the OP describes it is right around 5kblbs, as is a 4x4 MJ with occupants and fluids (or damned close). That means that under IDEAL conditions, the MJ/trailer combo should remain flat and stable while being able to efficiently brake from, let's say, 50mph. At 50mph, the combined trailer and MJ are exerting 500,000lbs-mph. That's a metric $#!& ton of force. Can it do it? Quite possibly. My ZJ is rated to tow the same load as a MJ. I have never had a problem gerting a load up to and beyond 50mph, and on flat land, controlled braking isn't a huge isse (though it IS interesting). My point being, if one is to be towing at or near the limit often, it may be safer and more efficient to purchase a beater tow rig with a higher safety margin. Let's keep in mind that force increases geometrically, not arithmetically.

[benjy_26]

For the record, if we were talking about towing 4k-4500lbs, I would totally be for it.

[Incommando]

Curb weight of a 4x4 MJ is from 3100-3300 for the varying lengths and options per the listings in two owner's manuals I have seen. If yours weighs 5,000 by adding two passengers I must assume that those passengers are soon going to have their own Lifetime Network reality show after someone knocks a wall down to forklift them from their houses.

 

What are the "geometrical" mathematical equations on the forces involved with braking that 8,000 # truck pulling 30,000 #? Can it do it? Not only "quite possibly" but absolutely. And in a safe enough manner for a liability concerned manufacturer to put it in writing. Just like a liability concerned Chrysler put it in writing that a properly equipped MJ could tow 5,000 #'s. Say the Dodge has 2.5 times the braking area of the MJ.  Would mean the upper limit of its safe stopping ability for a trailer weight would be 2.5 times that of the MJ using the examples cited?  But that would be ignoring the doubling of the curb weight of the tow vehicle and the effects of that weight on the stopping distance and... Hmmmm...I guess the forces multiple differently for the Dodge than the MJ?  :wavey:

 

All kidding aside we have to also keep in mind that the factory specs were for a new truck. The newest of MJ's is 22 years old and it would be a rare example that did not suffer from varying degrees of degradation. That being said the cash outlay for the purchase of even a beater dependable enough to tow with plus insurance, registration, etc for another vehicle... is probably much higher than it seems unless you find a smoking deal. A 4.0 H.O. MJ with a 4.0, AW4, and 3.55 gears has most of the puzzle pieces in place to tow what it was intended to tow IF the components are in good shape. Worn springs will cause the tow vehicle to wag considerably, for example. The added wheelbase that both of the MJ's offer is an advantage offer its SWB SUV brethren & cousins when towing, as well. A properly equipped MJ in good repair should not have trouble towing weights approaching its max. There is no easy answer but I have towed with an MJ with an estimated 3,500 # trailer and would not hesitate to do so again. 

http://www.fourwheeler.com/project-vehicles/154-0610-jeep-comanche-mj/

 

 

In closing let me just say that it's a simple question of weight ratios! A five ounce bird could not carry a one pound coconut.... M. Python  1975

[benjy_26]

don't get me wrong, I've towed at or above thr limits of my vehicles plenty of times, but if you're going to be towing right at 5000lbs on a regular basis, it may be time to consider something a bit bigger. I don't know how wheelbase and weight distribution come into effect (I'm no engineer... not THAT kind of engineer, anyway), but a Ram is very different from a MJ. BTW, wasn't a 4.0 4x4 metric ton model pushing very close to thr 4800lb mark towards the end of the Manche production cycle? I swear I read that somewhere... Add tools, fluids, people, and beer (what? It's for when you GET THERE :) ), and 5000lbs doesnt seem unreasonable. I've also seen precious few MJ's shod in the original P225 meats. Another thing to consider, as this works against the brakes.