ep86, What most everyone is trying to tell you in one flavor or another is that *SAFE* Gross Vehicle WeighT is dependent on drivetrain components and brakes. 300 powered F150's with M5OD's and (most likely) 3.08 open differentials do not normally play nice with trailers that gross over 3000#'s. Even if you have 3.55's or better the standard clutch for the M5OD will slip with a load that exceeds 3500#'s (been there done that). Add to that the stock brakes have a tendency to overheat with those kinds of loads. Not to mention that tongue weight will be an issue also.

If you want to pull that kind of weight there are some things that you can do:

Work with a good shop and put in a larger clutch. (better replace the M5OD with a ZF-42)

Swap the rear springs to larger capacity ones. (may need to box the frame as well)

Change to a limited slip carrier if you don't already have one.

At least swap to better cooling rotors and pads up front, better upgrade to larger front disks and wheels. Maybe change from drums to disk for the rear brakes.

Oh, and the engine is not you limiting factor for that trailer.

 

What he said^^^ for the most part. The stick is not rated to pull that kind of weight. The E4OD is almost. GVW is in your owner manual. I have a 94 with the E4OD and 3.55 limited slip rear end, if I do my math right it should be able to pull abot 3200# give or take. The 5 speed stick is rated much lower, and is much weaker as noted above. Now, having said that I can tell you that you don't really want to put your truck through that kind of test for another reason. They are getting old. That Mazda tranny will break, sooner than later when worked. It was designed for suburban use. Not pulling. If you got a bunch of miles on it, your asking to break something. At least do a very thorough check out of the vehicle, and maybe some upgrades are in order. I did a few recently to my 94.

1. Brakes, new and better pads.
2. Heavy duty shocks.
3. New trailer wiring harness.
4. New replacement trailer hitch.
5. New tires. BFG Long Trail T/A.
6. Rebuilt High output Alt. (More output, I forget how much, maybe a 120 Amp?), new serpentine belt too!
7. Oil Change with synthetic oil, not Dyno juice.

Oh, and one more thing. Even my truck would be overloaded by the Owners Manual pulling 3770# trailer. I have done it, it wasn't too happy pulling 4000#. And I have pulled as much as 14000# with it. But, like I've posted before. THAT WILL NEVER HAPPEN AGAIN. I beat on a rental first.

 

The M5OD will handle 4000-4500#'s just fine...as long as you don't use 5th(OD). As stated, the clutch is the fail point at these towed gross weights with that provision. Tall, sub 3.55, gears are also a problem when starting to roll.

Larger clutch, heavy duty transmission(ZF), and better diff gears with posi/ls carrier solve the drivetrain issues. After that it's the limitations of the frame, suspension, and brakes.

These trucks can be mod'd to handle this kind of load. Or take the route of larger truck with a strong diesel.

 

I wouldn't be afraid to tow that with my 84 F150: mild built 300, NP435, 4.10s, 33s, L/S ft, locked rr. Err I don't think I'd try it with my 96 F150: 300 stock, M5OD, 2.73s. I have probably towed in excess of 11k with my 84, the hardest part was stopping! BRAKES?

 

I have a 300 with the mazda trans and i'v pulled a 5000 lb boat easy and the boat isnt vary aerodynamic its more like a 11x8 ft tall brick wall. i kept it at 60-65 in 4th and it never even started to breath heard.

In town towing wasnt bad at all. and you have to try to avoid stopping on a up hill slop. even when i did get stuck on a hill you just have to let it work. And iv used it to pull out of some steep doat ramps without to much trouble.

The 300 is a vary powerful engine. But it gets all its power from torque. Thats the reason that they used these engines in UPS trucks and in F600's. And why all the big rigs and heavy machinery run diesel I6's.

Your weak link is everything behind the engine. Trans, diffs, gears and axel shafts.

Good luck with towing.

 

I agree, it's all in the gearing. With the combo I have in my 84 I have never run out of pulling power to where it wouldn't move the load.

 

Well, I'm here to report that I loaded up 2260 pounds on my old truck today, and I could really tell a difference! This is the most I've put on it yet (loading scrap to the metal recycling plant). It wasn't hard to take off with at all, but I didn't go over 45 with it and kept it in 4 gear all the way there. It didn't have any *umph* left to say the least, but it did have to torque to pull it up the hills in the same gear I normaly pull them in. I was really suprised on how the truck pulled, and especially how little it was squated (I had about half on a 5x10 trailer and the other half on the truck...appliances). I know I could pull alot more than that.

I have 3.55 gears in mine, though, and I don't think I'd have any trouble pulling that camper.

Matt

 

If you're running a 3.08 rear end... it'll pull it once it's started. Better hope you've got some meat on your clutch.


My '95 F150 SWB reg cab 300/M50D used to be my sandblasting truck. I'd put 3000 pounds of sand (bagged) in the bed and tow an Ingersoll Rand 185 John Deere diesel powered aircompressor, with all the accessories and air hoses.

If I recall I believe the most I ever towed / carried was about 7000 pounds... 3k in the bed 4k towed.

Yeah the bumper was on the ground but I made it 60 miles to the job site and back at 70mph.

The trick is in the gearing my friend. I've got 3.73's with a 31 inch tall tire. It's pretty steep around town and i'm in 5th by 45-50 mph... but it'll still pull up to a hundred.

The reason everyone doesn't think the 300 is a good towing engine is because alot of people out there don't know crap about trucks or truck engines. They lump all 6 cylinder engines into the same category. They don't know the difference between inlines and V's. It's a lack of education. If your truck had a 302... you'd stand less of a chance of pulling that trailer.

Goodluck with your towing experiment.

 

Good for you Matt! Basicly you have found out that you indeed have plenty of power (torque) on hand with the six! Enough that you if you let it run out, it is fast enough to get you a speeding ticket in any of the 50 states! So you need to slow down a little bit, but you still get to where you are going Besides, you will pass right by those higher horespower fuel guzzlers when they have to stop at the pump!

I do agree that the clutch is the weak point, so take it easy and don't stop and start on hills.

David

*And yes, I would choose the 300 in my own trucks if it had been available in 86 with fuel injection.

 

Yeah man, I'm just sick and tired of everybody telling me "It doesn't have power to do it" My grandpa has a 4.6 v8 engine in his truck and he saids that his and mine will not do the trick. Cjsteak, you ever had someone told you that your truck could not pull but you proved them wrong? I mean I've been wrong before I not going to lie about it , I just hate when they mis understood the power of the inline 6. Okay, what will towing be like with a 302? You probally could tow a trailer with a 302 if it had low gears, anyone in here had a 302 for a truck? If so how did it tow compared to inline 6?

 

The 4.6 Will make 280 ft lbs at 4,000 RPM's. The 4.9 makes 260 at 2,000 RPM's. The 4.6 makes about 50 HP more though. That's about the only advantage (I'm not bashing the 4.6).

The 300 is a beast

 

My Ford Spec book says the 4.9 offers 250 torque at 1600.

 

I tow with the 302 (I wanted the 6, but no EFI in 86') - I have had slightly over 8k on the hitch with no problems. So i slowed a little on the steeper hills, but nothing that I did not make up on the downhill. I do think that I have to keep a higher RPM level with the 302 over the 300 though to make up for the 302's lesser low speed torque. No big deal, right foot goes down...

Once I start rolling, I stop for nothing except traffic/hazards, could be old truck driver habits, and I have yet to be beat to a destination by any of my higher horsepower buddies, but then I made it from Seattle to LA in 14.5 hrs and back in less than 14 hrs with a 4 cyl S-10 so I don't have any quelms about putting my right foot into it. Foot to the floor does not bother me in the slightest, and at 48 years old I have driven this way my entire life, without any engine issues.

I sure don't want to pay for the extra fuel that a larger displacemnt engine will use when not towing just to get up the hill a slight bit faster.

at least it is what works for me - David

 

Travel Trailers & Fifth Wheels
1997 AEROLITE
DUTCHMEN MANUFACTURING
M-25RB


Length/Width: 25' x 7' 1"
Axles: 02
Weight: 2,905
Self-Contained: YES
Slides: N/A


That's the manufacturers info. The only question is whether you truck is well kept, and that your rear frame where the hitch mounts isn't rotting like my 89 did.

I have pictures in the gallery of a 4.2, M50D, 3.08s towing shorter, but older and heavier, no issues. And I think we all will agree that the 4.9 is better equipped to pull than the 4.2.

 

So figure 4k-5k loaded. As long as mountains don't figure in your travels you should be fine. Headwinds will damn near bring you to a stop even in the flats.
My whole rig weighs about a thousand pounds less than yours with no real frontal area. I can drive 55MPH up any mountain pass in third gear with the modifications I have done and I feel my truck is at it's limit.

YMMV,

Vince