csddmoyer4

First post here. I have a 1992 F150, XLT, 4x4, long bed, front quad shock. 302, automatic. I am in the process having a Rough Country 4" lift w rear springs and the quad shock package to keep it the same. Planning on putting 35" tires on after.
Question: What is the truck rated at for towing a travel trailer with the quad shock handling package? And will I lose towing capability with the 4" lift?


Thank you

Martian

Moved to Towing / Hauling / Plowing.

csddmoyer4

Thank you

smokeywren

No idea for an F-150 that old. That poor ole pickup is 24 years old and will be eligible for antique license plates next year. The oldest my info goes is 1997 model year. The 4.6L V8 had replaced the 302 CID V8, but probably similar towing capacity. GCWR for a standard '97 4.6L with standard long legs for highway cruising was 10,000 pounds. Assuming wet and loaded pickup weight of 6,000 pounds, that leaves 4,000 pounds for tow rating with standard tire diameter.


But the 35" tires are at least 10% taller than standard, which reduces the rear end ratio by about 10%. So your real-world tow rating with the 35" tires is probably around 3,600 pounds.



Lift? No. But tires? Yes. The lift will cause increased aerodynamic drag, so it will reduce your towing performance at high speeds, but probably won't be noticeable if you keep the speed down to 55 MPH. The tall tires changes your effective rear axle ratio, so yes, you'll lose towing capability when you mount the 35s.


That antique pickup with a lift and tall tires might look cool, but it won't tow much. I probably wouldn't try to tow more than about 3,000 pounds with it. And even towing 3,000 pounds, watch the tranny temp and don't allow it to overheat or you'll have a dead truck in no time.

SixShooter14

Along with what smokey said, I'd recommend lowering the axle ratio if you haven't already.

csddmoyer4

Thanks for all the information so far. This is great info. I have not done the gears yet. I have been looking around for the best size. What would you guys recommend? 4:10 or even lower?
And if you happen to know what part numbers you suggest for the front and rear diff that would be great. Thanks again

csddmoyer4

Sorry, Don't know how to delete the quote.

smokeywren

The best source for ring gear and pinion parts is Randy's Ring & Pinion. However, do not order parts on-line until after you have found a really-good mechanic with lots of "rear end" experience that will agree to install parts you provide. Most really-good mechanics want to make the profit on the parts as swell as the install, so they will not install parts you provide.


And don't even think about DIY. Adjusting a differential requires special tools and a fine touch, so if you aren't experienced with successfully working of a differential, then pay the expert to do it for you.



All the info you need is available at Randy's ( https://www.ringpinion.com/DiffWizard.aspx ). Your front diff is a Dana 44, and the rear is a Ford 8.8 with 30-spline. Ratios are available in 3.54, 3.73, 4.11, 4.56, 4.88, 5.13, and 5.38. The ratio you want depends on the weight of the trailer you intend to tow.


For the normal 24' travel trailer that has GVWR of 6,500 to 7,000 pounds, you would want at least 4.56, and the shorter legs of even the 5.38 wouldn't be too short for dragging that trailer over the mountains. Of course the short legs for towing over the GCWR of the pickup ruins the pickup for running empty on the interstate.


For the smaller travel trailers with GVWR less than 5,000 pounds, the 4.11 would probably be fine if you stay out of the mountains.


If you promise not to tow more than about 3,000 pounds, then I'd probably go with 3.73.


But the expense of changing both the front and rear ring-gear and pinion sets is only your initial expense to trouble-free towing with your antique pickup. You must also install a monster-size tranny cooling system as well as the biggest radiator available that will fit under the hood. And don't leave home without an excellent set of gauges for coolant temp, tranny temp, and motor oil temp. The stock gauges are simply not good enough. If you overheat the engine or tranny, you'll have a dead pickup before you can sat "Scat"! And towing a TT is an excellent way to overheat the drivetrain in any tow vehicle.

csddmoyer4

Thank you for all that information. Very knowledgeable. That's great

jp360cj

^^This. I've had best luck with 4x4/Jeep shops doing good gear work.

If your gears are 3.54 or numerically lower, you made need a new carrier for the front. (D44 carrier break is 3.54/3.73) Sometimes you can get "thick" gears and use the 3.54 carrier. You're front may be a High Pinion (HP/reverse cut/reverse rotation). Randy's website is good for determining axles based on vehicle.

Here is a good site for figuring out what gears you want : http://www.grimmjeeper.com/gears.html

According to the calculator (used 34.5" for tire size since most 35s aren't actually 35" tall)

4.10:



4.56