Can i legally haul this tractor ?

[Soundguy]

I've pulled much more than 6500# with a 97 350/3:73 combo..SB Reg cab 4x4...No problem...Trailer brakes are a must...The truck ain't gonna stop that load alone, no way.

well.. heck I guess it should. my 99 7.3psd f350 / 4.10 drw pulls 14k fine.. but he ain't got that. he's got a 1/2 ton...

1997 chevy Z71 4x4, it has the 350 motor and 3.73 gears

big difference...

but all of us agree.. he needs the brakes!

 

[Soundguy]

on a re-read.. is that a 350 eng in a 1/2 ton.. or a 1 ton/ 350 ? can't tell.

that does make a difference in my reply..

 

[timswi]

on a re-read.. is that a 350 eng in a 1/2 ton.. or a 1 ton/ 350 ? can't tell.

that does make a difference in my reply..

Sorry, my bad...1/2 ton...All it had was the gears and a towing package...I pulled with it as God created it except for the K&N filter.

I was actually agreeing with you...Sorry if it came off wrong.

 

[Soundguy]

naw..it was me... it was just I read it at first as a 350 ( f350 ) not a 350 engine in a half ton. so my bad.

soundguy

 

[Oldtractorfixer]

I wouldn't worry about that combination provided you get the brakes. You are in Florida which is flat. That makes a difference. What makes trailering much better when you are appoaching the upper limits of capacity is to come up with an equalizer hitch. You will note the hitch ratings (on the tag on the hitch) that the ratings for your truck are all dependant on an equilizer hitch. This keeps the truck flat with an apporiate amount of tongue weight. If you load with too little tongue weight it gets scary, the whole combination is unstable. If you have excess tongue weight without equalizer you overload the back of the truck. You can often find a good used one on CL.

 

[Dmace]

trailer is right onthe edge at 7k ( 1700# trailer usually for 16'.. leaving you 5300 cargo.. which the tractor eats up )

Many people don't understand this so it needs to be said everytime there is a question about trailer capacity.

A 7000 GVWR trailer that weighs 1700 lbs DOES NOT only have a 5300 lb capacity. Many people forget Tongue Weight which should be between 15-20%. In the case of a trailer loaded to it's max 7000 lbs, that means 1000-1400 lbs should be on the truck and not the trailer leaving more capacity on the trailer.

A trailers load capacity should be GVWR+TONGUE WEIGHT-EMPTY TRAILER WEIGHT.

So that 7k trailer that weighs 1700 lbs setup with 20% tongue weight has a capacity of 6700 lbs. Still needs brakes though!

 

[s219]

A trailers load capacity should be GVWR+TONGUE WEIGHT-EMPTY TRAILER WEIGHT.

I am not disputing this (can be verified by summing forces=0), but with that logic a trailer with 7000# axles and 10% tongue weight could really have a gross of 7778# (7000# on the axles and 778# on the tongue). So why wouldn't the trailer be rated to 7778# gross instead?

I think when trailers are rated 7000# gross, that is an operational system rating, for the whole trailer. It would cover all bases, regardless of balance, under the assumption that the most severe point load that could be supported would be the one that is right on the axles. Conceivably, someone could load the trailer (even temporarily while driving a tractor on) so that all 7000# gross was over the axles and tongue weight was zero. In that scenario, you would have maxed out the capacity of the axle subsystem (even if temporary) and that is suddenly the determining factor or limit for the whole system.

Sensibly loaded and balanced with 10% on the tongue, yes, you can feel OK about a 7778# gross. But the most severe case of 7000# gross right over the axle, is the one that probably sets the operational limit and goes on the sticker.

 

[Dmace]

Couple of things wrong with your logic, you are assuming that the axle manufacturers create a 3500 lb axle knowing that 3501 lbs will snap it in half. This is not true, there is a margin of safety involved and it's typically 30% in any design.

Secondly, there are plenty of trailer manufacturers that use the tongue weight in figuring GVWR. Heres an example from Hudson Trailers:
20ft equipment trailer
8,950 lb GVWR
1,950 lb Empty weight
7,000 lb Payload (with adequate tongue weight)
Two 3500 lb Dexter axles
http://hudsontrailers.com/docs/details/hse3t.php
I feel trailer manufacturers figure typical consumers would not understand tongue weight and see an 8-9k lb trailer with 3500 lb axles as deception.

 

[Soundguy]

Couple of things wrong with your logic,.

Good job for splitting the hair.

The guy, obviously if asking the question, is new to trailers and weighting.

using the gv - trailer weigh = cargo weight is a 'SAFE' rule of thumb to go by.

that leaves you some room for fuel and oil in the machine.. an extra gas can.. maybee a tool box.. spare tire, and yer pile of load binders or chains.. which I wager most people forget to weight. also accounts for the wood or concrete chock blocks for tires, adn the block some throw under the trailer rear to keep it dipping.

IMHO.. it's a safe rule, vs maxing out the last ounce of yer trailer hoping you got the exact tounge weight right.

soundguy

 

[s219]

Couple of things wrong with your logic, you are assuming that the axle manufacturers create a 3500 lb axle knowing that 3501 lbs will snap it in half. This is not true, there is a margin of safety involved and it's typically 30% in any design.

Oh, I agree with you there -- what they rate the axles for definitely has a factor of safety built in, generally 25-35% under the ultimate capacity. But they don't ever rate to that ultimate level, and most companies keep the margin numbers very private (true of factors of safety in any industry). I have never seen 3.5K axles rated as anything else. The margin is there to cover their butts, not ours.

I think it's good that Hudson is showing real-world numbers that factor in the tongue weight -- it gives a realistic assessment. Almost every other trailer company I have looked at lists gross as the net axle rating. Of course, Hudson uses an extreme number -- it would be about 21% tongue weight and the vehicle would need to be able to handle 1950# on the hitch to get to the full trailer capacity.