Towing a TT with an old half ton truck questions

[9c1fanatic]

Well I bought the trailer yesterday.  A Grand Design 2400BH.  I weighed the truck on its own before picking up the RV (including a creeper, 8 ft ladder, 4 way lug wrench, and hitch)

4580 lbs
2540 Front Axle
2040 Rear Axle

I returned to the scales after the PDI and here were the new numbers:

Front Axle 2440 (lost 100 lbs) compared to unloaded
Rear Axle 2720 (gained680 lbs) with tongue weight + WD hitch
Trailer Axles 5360 lbs.

Total combined weight of the whole rig 10,520 lbs.  If I subtract the unloaded truck weight of 4580 from 10,520 I get an approximate trailer weight of 5940 (some of this weight is the WD hitch and accessory kit in the trailer, and residual water in the systems) which is not too far off from Grand Design's UVW of 5814.

Am I correct in calculating my tongue weight by subtracting the difference between the before and after rear axle weights on my truck?  I realize some of this is the WD hitch but 680 tongue on a 5900 trailer seems pretty close to me.  Does anything look concerning with my weights or calculations.  As mentioned earlier in the thread my tow vehicle GVWR is 6200.

Also for reference, the truck towed great and handled the trailer well.  Rear of truck squatted 1.5 inches total.  Obviously not the power and gearing advantage of newer 1/2 tons but will work for now for close range trips.

 

[Lou Schneider]

You really can't estimate the tongue weight by looking at the change in the truck's rear axle weights when using an equalizing hitch.  By design, the equalizing bars transfer half of the weight they're equalizing back to the trailer's axles. 

You could disconnect the equalizing bars, then take the change in the weight of the truck compared to it's empty weight to get the tongue weight.  If you use individual axle weights, this means adding the weight gained or lost on each axle.  For example, if the rear axle gains 600 lbs. and the front axle loses 100 lbs. the gain in weight is 500 lbs.

But this will only give you the tongue weight to the resolution of the scale, which on the one you used appears to be 20 lbs.  This can give an error of up to +/- 10 lbs using a single measurement for the truck's total weight or +/- 20 lbs. using two measurements for individual axle weights.  A more accurate measurement can be obtained using a tongue weight scale under the tongue jack, or lacking a tongue scale by using a bathroom scale and a beam multiplier as shown here:

https://www.etrailer.com/faq-how-to-determine-trailer-tongue-weight.aspx

5th wheel trailers can use rear axle weights to find the trailer's hitch weight as the 5th wheel hitch is directly over the rear axle so all of the pin weight is carried there.

 

[cerd]

I agree but that can turn into alot of money.  I looked at the cheepo style spring helpers and I dont trust them.  I would have to go with the good ones when and if i do it and that is going to be $400 to $500 for the pair.    The nice guy down at the suspension shop gave me an estimate of $375 per side for the air lifts, isn't that nice of him  LMAO

This year was my property purchase, next year is a cover for my truck, the next year is a boat, and then it will be ready to spend the next year doing some upkeep on the RV again such as new or painted roof and some other things.  Then ill be fishing most every day after that

Have you considered looking at used parts from salvage yards? I bet you can get a good set of HD springs and a 3.73 rear axle for under $400. The springs should be compatible with your mounts. Just look for one with an extra leaf or 2. I believe they are sold with up to 8 leaves.

If you do this yourself, just cut the spring bolts and the Axle's U bolts and replace with new. It saves a lot of headache. 

There is a jumper in the cluster to recalibrate the speedometer to the new gear ratio. www.chevytalk.org/fusionbb/showtopic.php?tid/258562

 

[9c1fanatic]

Thank you for the information.  That makes sense to use a scale due to the WD hitch, but for the purpose of seeing how much weight is on my truck to figure out the remaining payload capacity I have, this should work right?

And yes, I will be making a trip to the salvage yard soon for the 3.73.  This truck only has to do the job for about one more year but there is a reason its called the Texas hill Country?

 

[grashley]

You are wise to get those weights!

The hitch wt is really how much more the truck weighs with the TT attached, without WD.  Your numbers are slightly skewed because you added weight to the truck - WD hitch - and moved weight off the truck with the WD hitch moving weight back to the TT.  However, this is not an exact science.  Weight without trailer was 4580.  With trailer  5160.  Difference  580.  That is more information than many folks have, and really accurate enough for this stage of towing.  Tongue wt is marginal, but likely OK.

Once you load it up for camping, get it weighed again.  You will also need to readjust the WD hitch for the new weight being loaded.

You are on the right - safe - track!

 

[9c1fanatic]

Thanks for the kind words.  The installer said due to the height of my hitch he could not get the (unloaded) trailer exactly where it should be.  He said he can either get me 1/2 inch low or 1 1/2 inch high because the WD hitch only has limited adjustment.  I had him leave it 1/2 inch low since that seemed closer and safer that 1.5 inch high.  He said I could move it to the 1.5 inch high setting after I load the trailer but I'm not convinced I will add that much weight.  I stocked the trailer today which consisted of the connection hoses, electrical cord, electric impact, a few blocks of wood, two camping chairs and bedding for two beds.  The food and drinks will go into an ice chest and stay in the truck.  My mountain bike also went into the trailer.  This is the typical way I will load it for camping at nearby state parks and I really don't see all this stuff being over 400-500 pounds.  So am I better leaving the hitch a tad low or a little more high for this set up. 

When I take the longer trips, I load way more into the thing but I'm using a borrowed Ram 2500 for those trips.

 

[IBTripping]

I think you will do fine. You know you are close to or above the tow vehicle rated capacity and plan to take precautions. Also, the weight distribution/sway control hitch will help keep you out of trouble. Drive safe and enjoy!

 

[scottydl]

Congrats on the purchase! And yeah as others have stated you're right on track for the best towing experience. When it gets down to a matter of .5 - 1.5 inches difference... You'll probably be fine either way! See how the rig tows and you can always make WDH adjustments later if needed.

 

[9c1fanatic]

Thank you to all that have replied.  I am very pleased with how this almost 30 year old truck tows this trailer!

 

[scottydl]

My 1995 Suburban 3/4 ton knows just how that feels!

 

[Wireman134]

Here's a useful article showing a couple of different ways to determine the tongue weight.

https://www.etrailer.com/faq-how-to-determine-trailer-tongue-weight.aspx

The scales mentioned are available from Amazon, if you choose the bathroom scale method I'd follow the example in this YouTube video for a greater range:

https://m.youtube.com/watch?v=nMoLA44lcgU

Yes, tongue weight does not change much. But it does. I have scaled my TT with bars loaded and then unloaded and confirmed my tow vehicle has more weight on it's axles (GVW) with bars unloaded. Approximately 80% of TT's tongue weight stays on the tow vehicle with bars loaded, 20% is distributed to trailer axles. I have scale tickets proving weight is restored to front axle, exact amount as if trailer is not hitched.

All a weight distributing hitch does is create a bridge across the hitch ball to force the front end of the truck down to the original ride height.  Without it the truck's rear axle acts as a fulcrum and as you add weight on the hitch the front of the truck rises and removes weight from the steering axle.

As the equalizing bars force the truck's front end downward, the front springs compress properly and transfer the correct weight to the steering tires.  It does not change the trailer's tongue weight.

Tongue weight is another way of expressing the location of the trailer's Center Of Gravity.  If you have weight on the hitch the trailer's CoG is ahead of the trailer's axles and it will be a stable tow.  You need enough tongue weight to keep the CoG forward of the axles when things like wind resistance on the front of the trailer and bumps, etc. try to push it rearward.  Letting the CoG get behind the axles is what causes sway to self-amplify.

 

[9c1fanatic]

Just thought I would post a final update on this topic.  thanks to all that helped.  The old 1991 C 1500 served honorably and reliably for close range trips for a year.  I was borrowing a Dodge Ram 2500 for longer trips but finally settled on my own permanent tow vehicle.

Long story short, I went in to buy a used Silverado 1500 but wasn't satisfied with the prices they were asking and lack of Max towing optioned trucks for the increased payload I know I would eventually need.  Also my family grew in this time.  I ended up buying what I believe to be the best keep value secret to getting into the "HD truck world" lol.

I bought a 2019 Chevrolet Express long wheel base 3500 van.
6.0L L96 V8
6L90E HD transmission
14 bolt 10.5 inch full floating axle with G80 option
10,000 max trailer rating
3,100 lbs of payload!! and that is with all the seats installed
1000 hitch rating

I know its an old platform but a cheap way to get into the 2500/3500 towing vehicles with all the added utility of such a versatile vehicle.  I can even open the back doors with the trailer attached!  It tows the Grand Design 2400BH really well and the mileage is surprisingly good.

 

[Rob&Deryl]

A note on scales...

CAT scales allows you to declare you will want a re-weigh when you ask for your first weight. Think dump trucks on the way to pick up a load of gravel... the second weigh is only a couple of $$.

 

[scottydl]

I know its an old platform but a cheap way to get into the 2500/3500 towing vehicles with all the added utility of such a versatile vehicle.  I can even open the back doors with the trailer attached!  It tows the Grand Design 2400BH really well and the mileage is surprisingly good.

Nice! My sister and family (husband + 6 kids) are home-schoolers, so they've always had "the big van" that is somewhat stereotypical. My BIL is a Ford guy so theirs have been F-series, but at least 3/4 ton and they have pulled two different 30'+ travel trailers all over the country with them. Now let's see some pics! 8)

 

[Gary RV_Wizard]

Great choice!  A one-ton van makes an excellent tow vehicle, especially if you have a big family, but many people are too style-conscious to own one.

 

[9c1fanatic]

So true.  Although I grew up with big vans, they are not my first choice but I do think the Chevrolet/GMC vans look way better (more truck like) than the Euro imports from Ford/Chrysler.  Any you get so much more vehicle for the money.  I didn't want tech, I just wanted a solid powertrain and platform for towing and that's what the Express delivers.  Such an all purpose vehicle. 

I'm getting about 18 MPG unloaded on the highway and 8-10 towing (depending on wind direction and speed).  I'm happy with it and my travel trailer seems a lot taller and definitely heavier than most TT in this length class I come across.

 

[9c1fanatic]

One more from Lake Brownwood

 

[SpencerPJ]

Looks great and great choice.  Enjoy the time with the kids while they are little, great memories.  Be safe  )

 

[cerd]

I wonder if one of those wind deflectors would help boost mpg at all in a full size van while towing.