Increase Towing Capacity

Hi, Im looking to beef up my suspension on my explorer. I would like to increase the towing capacity. Have any suggestions?

 

[joecrna]

Increasing towing capacity involves a whole lot more than just increasing spring rates to carry extra weight on the rear. The short, incomplete, list includes brakes, trans cooling, springs, power, engine cooling, axle housing capacity, axle bearings, and even the frame rails. Just how much do you want to pull?

 

[steffel]

I plan on getting a new car to replace the truck. I want to keep the truck so I can pull a trailer when needed. If possible for a v6, I would like be able to tow 4-5 tons (8000-10000 pounds). What kind of work and parts would be needed for this?

 

[joecrna]

Thats fricking heavy. The exact nieghborhood of what I tow. You need all of the above. Even the hitch reciever will be a problem, it's got to be custom. No one makes one for an Explorer that strong. Then you've got sway to consider- only real answer is a Pierce Arrow hitch ($2000). I've got an enourmous trans cooler (29000 BTU) plus the Ford coolers, last week while going to my parking location I had the throttle wide open, 4WD slipping slightly and could barely maintain 10mph. Trans temp alarm went off at 325 degrees, it pegged at 350. Fluid fired but no clutch slip. Only way to brake that much weight is with tandom or triple axles on the trailer and all wheels with brakes and a high end controller.

Springs are the easy part. I havn't boxed the frame yet but I did add multiple cross ties, plates and gussets. Engine cooling hasn"t been a problem but when it is a 4 row aluminium custom job is in order. The rear solid axle still lives, and truth been known, its still in capacity specs. Just not when installed in the Explorer. Power is a big problem. Im in the process of dumping about 20k in the engine and will be lucky to have 200 HP, barely adequate.
I've spent maybe 15k on the rest of the truck so far, it is very expensive. Best to buy something else unless you really want to "make" an Explorer do it.

 

[steffel]

Parts?

Do you have any brands or parts that you recommend for the categories you've listed above.

 

[joecrna]

Are you seriously interested in going down this road? I didn't think anyone was as crazy as me. What do you plan on towing? If you do undertake this project, remember, a few short years ago (when my Explorer was built) only well equiped one ton trucks and E350 vans could undertake towing this much weight.

First up is a stout hitch. I started with a Draw Tight class IV/V hitch receiver. This hitch is a rectangular tube receiver. It proved a good fit on my truck and was able to clear my 31" spare tire. Its rated at 7500lbs with a weight distributing hitch (the only feasable type when towing heavy). You will then modify this for any extra needed capacity. Forget the manufacturer, they won't answer any questions and prohibit modifying their product in any way. Liability cancerns are out of control in this country. By the way, I don't recommend actually doing any of this. Its just a mental exercise. A what if! Thats my disclaimer. Start by looking at the hitch receivers on one ton trucks with class V hitchs, usually square tube that attaches to the frame at multiple points with about 6-8 bolts per side. The Draw Tight receiver attaches to the frame in a similar way and spreads the load over a large area of frame rail. I than reinforced the frame C channel and added a few more bolts (grade 8 only). You might consider fully closing the rear half of the frame to create a boxed frame instead of a weaker C channel. That leaves the tubing of the hitch receiver itself. Ours is a rectangular tube instead of a square tube but the wall thickness is similar. If needed you might consider reinforcing this tubing too.

Next you need tires of suitable load carrying capacity. Depending on equipement, accessories and how you load it, your Explorer will weigh between 4800 and 6500 lbs with a full tank of gas and the hitch loaded. What exact model/equipement does your Explorer currently have? My tires are 31x10.5 BFG All Terrains. This is a floatation tire as opposed to a LT (light truck) or P (passenger P metric). As you research tires you will find that weight/load ratings differ for all of these classes of tires. What is stamped on the side as a max load rating and pressure (sometimes max PSI) not only varries by size (rim diameter is most important), manufacturer (only very slightly), load range (C,D,E- a fairly big difference), but also by type (LT, P metric, floatation, medium duty truck). Max doesn't always mean max. The tire industry asigns load ratings using industry standards. My main point is that with floatation tires, that max weight rating is the max at 50psi. All tires load capacity varries greatly with inflation pressure. In the case of a flotation tire, 50 psi and the corresponding load limit isn't necessarily the max allowed. Even experienced tire salesmen don't usually know this. You will need to do indepth research about tires and their manufacture. There are several seeming inconsistancies among tire ratings but these are really just how the industry decided to define the rating.

If you go this far, you should have already dealt with transmission cooling and monitoring. If you are still interested at this point, let me know and we will continue with my hard learned insight. In the next couple of months I was planning on starting a thread on my triple threat Explorer (Heavy towing, moderate off-roading and a daily driver). I was going to quary the forum for their collective insight on the design of this truck. Many of the modifications have already been done and most of the remaining design is complete but somethings could be changed if a good arrgument to do so is presented. Thats a topic for another thread though.

As I said, if your are still interested in modifications for heavy towing, we can continue on. Let me know the starting point for your Explorer. Sorry to ramble but the server was busy and I had time.

 

[thebrakeman]

You need a 3/4-ton pickup, my friend.