I'm in the market for a 250 or 350 with a 300 in it but I don't know the towing capacities of any of them. Its hard to find any for sale with that engine in it...and extended cab and 4wd. I am being a bit picky i know but i'm in no hurry.
I'd also be interested in finding out the towing capacity of a 150 with the same engine. I can't find any of that info on the net. let me know what yall find out! thanks,
Erik in KS

 

kinda an old line but I would say that the towing capacity is limited only by the brakes.

I have towed over 12,000 combined with an F150 powered by a 300. The brakes were taxed but the engine was fine sae a bit short on power and having a max safe speed of 55.

 

Why are you responding to an almost-3-year-old question?

 

I totally concur. A 300 will tow anything that can be towed with any other engine. Might not be as fast at doing it, but it'll certainly do the task.

Cause we can........

Yeah, I saw it was a 3 year old unanswered post, but I still had to reply.

 

For completions sake, and for the search functionality...

Information comes from the 1981 owners manual...

300-6 Engine with automatic transmission with Gross Vehicle Weight Ratings, and Gross Combined Weight Ratings in LBS...

F-100 with min axle ratio of 3.00: with Light Duty Tow Package
Class I Trailer / GVWR 4700 / GCWR 6500
Class I Trailer / GVWR 5000 / GCWR 6800
Class I Trailer / GVWR 5150 / GCWR 6800

: With Heavy Duty Tow Package
Class II Trailer / GVWR 4700 / GCWR 7675
Class II Trailer / GVWR 5000 / GCWR 7975
Class II Trailer / GVWR 5150 / GCWR 8125

-----------

F-150 With 3.00 min axle ratio: With LD Tow Package
Class I Trailer / GVWR 5250 / GCWR 7050
Class I Trailer / GVWR 5800 / GCWR 7600
Class I Trailer / GVWR 5450 / GCWR 7250
Class I Trailer / GVWR 6100 / GCWR 7900

with 3.25 min axle ratio and HD Tow
Class II Trailer / GVWR 5250 / GCWR 8225
Class II Trailer / GVWR 5800 / GCWR 8775
Class II Trailer / GVWR 5450 / GCWR 8425
Class II Trailer / GVWR 6100 / GCWR 9075

----------------

F-250 with min axle ratio of 3.33: With LD Tow
Class I Trailer / GVWR 6350 / GCWR 8150
Class I Trailer / GVWR 6900 / GCWR 8700
Class I Trailer / GVWR 7650 / GCWR 9450
Class I Trailer / GVWR 7800 / GCWR N/A
Class I Trailer / GVWR 8650 / GCWR N/A

Manual Transmission: Footnote #5: Do not tow trailers with manual transmission equipped vehicles.

Those are Fo-Mo-Co's recommendations on minimum equippment. Recommended equipment would be Extra and Super Cooling packages, stabilizer Bars, front rear, etc... Only what is recommended to tow with the 300 is listed above. I did not want to post a page full of N/A's

 

I find it funny that footnote #5 exists. The primary reason most people give for opting for the 4 speed, is the ability to easily get heavy loads moving without having to ride the clutch.
Also, by 94, that had changed. The offical towing capacity of a 300/5speed/3.55 94 F150 was 3500, but the same engine/axle with an auto was rated at 5000.
I had a 94 F150 300/5speed/3.55, and I regularly exceeded 5000 lbs trailer weight with it.

 

I think most of that was for warranty issues. Burn up a clutch towing trailers under warranty would not be covered etc...

 

I can see that. Of course, burning out the clutch was never covered under warranty to begin with. Same with brake pads/shoes. Only time I've ever seen these covered under warranty, was when the lining fell off due to faulty rivets.

 

I have alwayes figured that a 7000 lb load was about the max safe load to be towed with a half ton and a 9000 lb load with a 3/4 ton.

A tonner depending on the setup may be anywhere from 10000 to 14000.

Why shouldent I tow with a manual? That is a big reason that I buy them. Cause I can stop a load damn quick if I need to.

 

If you take into account what Ford Recommends, and do the math, then a F-150/300-6 with a GVWR of 6100, with the bed fully loaded, can only tow, aproximately 2975lbs with a class II trailer. With the bed empty, aprox 3500 to make the math simple as that's the maximum for a class II trailer.

Now if you had a F-150 with 351V8, with a min 3.00 axle ratio engine then the maximum goes up to a class III trailer with a maximum of 4700lbs if the bed is empty. Any weight in the bed reduces your trailer weight maximum.

To get your 7000 LBS you need at least a F-250 with a GVWR of 8650 and at least a 400V8 engine with 4.10 gears. That would bring your maximum up to 7200 that you can tow with a Class IV trailer. With an empty bed.

This info comes right from the book.


The only reason why I can think of is the reason I stated above. To void the warrantee if you do. My manual states it plain in black and white, do not do it. Since the warrantee is no longer valid, I don't see why you couldn't or shouldn't. There is no official numbers for manual transmissions though on what it will tow safely. 1981.

 

Hmmm, then I wonder what the official purpose of the T18/19 and NP435 is? Just offroad?

 

That's a good question.

The official purpose for a manual on a 2013 F-150 is nothing at all, as it's not even an option on the F-150 anymore.

One of the many reasons I will not buy anything new from any manufacture. I will put the money into the old girl first because it's what I want.

My point being is speculation that even back in the 80's they didn't see much purpose in the Manual transmissions, other than the preference of the driver.

Ford definately thought the Manual Transmissions were weaker than the Automatics, even by Rouge-Wulff's numbers from 1994.

I tend to think the exact opposite...

 

Either the New Process transmission or the Borg Warner transmissions found in this year range F-series feature granny-gears. The T-19 is synchronized while the 435 and the T-18 are un-syncronyzed.

The benefit of a transmission with a granny gear is that you can put "highway gears" in a rear end. 2.73, 2.75, 3.00:1, and 3.08:1 gear ratios can be put in rear ends without sacrificing much tow-ability due to the low first-gear of these transmissions (example being the 6.69:1 low 1st of the NP435).

These transmissions were exceptionally heavy duty. You could get the T-18 in the F150's, T-19's came in 250's and 350's IIRC, and the New Process 435 was used all the way up through dump trucks.

So, you could get a truck with a heavy duty 4-speed to satisfy most towing needs that would be used with F100's and 150's (and still get the 4-speed grannies in the 250's and 350's with heavier rear gears for a heavier load), and you could still have decent highway mileage with the tall geared rear.

The other option was, you could get a truck that was purposefully designed to get good gas mileage with the Automatic OverDrive or the 4-speed OD manual. Both transmissions aren't what you would call heavy duty, but you could put taller rear-gears in the vehicle without sacrificing much in the way of mileage. You can have 3.50, 3.55, 3.73, 4.10, and 4.11 gearing in the rear end and it'll mimic what having highway gears in a granny geared transmission will give you, except instead of a low-1st, you've got an overdrive 4th. It isn't too uncommon to find a truck from this era with highway gears in it that isn't really suitable for towing heavy loads (weren't most of these F100's, RW and Franklin?)

The reason an automatic is recommended for towing is because you have torque converter slip. This replicates slipping the clutch with an automatic, and simulates having steeper transmission gearing. It's also fully automatic, meaning the driver doesn't have to down-shift or up-shift to accommodate varying speeds or inclines. You can also have lock-up torque converters, higher stall converters, and manual-shift valve-bodies to increase the towing ability of an automatic.

Some trucks also can have higher GVWR because of hydro-boost brake assist, as well as the bigger rear end and front end brakes that are commonly found on the 3/4 and 1-ton trucks.

4x4's with highway gearing and even low gearing in the rear and front benefit exceptionally from the granny-gear. With 3.00:1, 3.08:1, and on up through 4.56 and 5.12:1 gears, you can shift into 1st gear and 4-wheel low and your truck will be able to idle up steep hills. It's also common to find Ford trucks with slightly differing gear ratios. Fords reasoning was that it would allow the front end to pull a little more. For example, on my truck, the rear is 3.08:1 and the front is 3.07:1. The 0.01:1 difference in gear ratio isn't enough such that it would cause sufficient drive-line bind and thus damage the vehicle. To me, the difference is negligible and you would better be suited to find a limited-slip or selectable locker.

Granny-gear transmissions can serve many purposes, and match with the correct differential gearing, can nab you a good combination of towing power and MPG's.

X

Okay, my Ford infomercial is done for today.

 

NP435 was synchronized. One can shift from 1st to 2nd without coming to a stop with the NP435.

 

My 1981 F350 came with a T18, I don't think the T19 was being used yet (may not have been manufactured yet).