Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×
 

Go Back   Keystone RV Forums > Keystone Tech Forums > Towing
Click Here to Login

Reply
 
Thread Tools Display Modes
 
Old 08-21-2020, 07:42 AM   #1
P&DZ
Senior Member
 
Join Date: Oct 2018
Location: Fort Collins
Posts: 125
CAT Scale Questions

I finally had the opportunity to use a CAT Scale. This was a perfect opportunity since we were headed out for an 18 day trip and a worst case scenario loaded with food, beverages, clothes, bikes, kayaks, full propane tanks, solar panel, etc. The water tanks however were empty.

Scale Data as follows:
Steer Drive Trailer Total
Truck+Trailer with Anderson WDH 3,240 3,620 5,900 12,760
Truck+Trailer Anderson Hitch loose 3,180 3,680 5,880 12,740
Truck 3,480 2,640 6,120

Truck Specs: Camper Specs:
Payload 1,925 GVWR: 7,200
GVWR 7,600 GAWR 4,400 per axle
GAWR FRT 3,950
GAWR RR 4,300
GCVWR 16,700
Curb Weight: 5,675 (estimate)

If my calculations are correct:
Trailer Weight: 6,640
Tongue Weight with Hitch: 980
Payload: 1,417 (437 + 980)

Actual weight in the truck was 437lbs which included me, DW, cat, Kayaks, Tonneau Cover, few misc items.

Do these calculations seem correct?
Why do the first and second weights differ by 20lbs, is this expected scale error?

I was surprised only 60 lbs was transferred to the front axle with Anderson Hitch engaged? Is this expected weight transfer.

Is there anything I should be concerned about with these numbers? With the exception of the trailer weight it appears I have 27% margin with payload and 16%+/- front and rear axles.

Thanks!! Love this forum
__________________
2012 Cougar 21RBSWE
2018 GMC 1500 5.3L, 4x4, crew cab, max tow pkg
Andersen Hitch
P&DZ is offline   Reply With Quote
Old 08-21-2020, 07:45 AM   #2
P&DZ
Senior Member
 
Join Date: Oct 2018
Location: Fort Collins
Posts: 125
So sorry, the spacing on the numbers got messed up when posted, but I think it is understandable?
__________________
2012 Cougar 21RBSWE
2018 GMC 1500 5.3L, 4x4, crew cab, max tow pkg
Andersen Hitch
P&DZ is offline   Reply With Quote
Old 08-22-2020, 06:43 AM   #3
LewisB
Senior Member
 
LewisB's Avatar
 
Join Date: Aug 2013
Location: Tucson
Posts: 822
You've got a lot of GVWRs and GAWRs mixed together in the second paragraph and I'm not sure what goes where. Recommend you separate these out into distinct groups for truck and trailer. Rather than typing all the data, how about posting photos of the stickers and the weight tickets?

In the second weight, you state "Truck+Trailer Anderson Hitch loose".
1) Does that mean you just unloaded the WDH and the trailer was still connected?
2) Or does that mean the trailer was completely disconnected and free of the truck?

I'm a fifth wheel guy and certainly not an expert with pull-trailers. But it seems to me that you need 3 weight tickets to determine the actual weights of both the truck and trailer and the impact of the WDH;
  1. Weight of truck axles (front & rear) and trailer axles (combined) with complete separation between the truck and trailer.
  2. Weight of truck axles (front & rear) and trailer axles (combined) with WDH attached in a "loaded" condition.
  3. Weight of truck axles (front & rear) and trailer axles (combined) with WDH attached but in an "unloaded" condition.
So the first weight gives you the true weight of both the truck & trailer. The landing gear on the trailer needs to be isolated from the truck. Some scales can give you front landing gear + axles, some will just combine those weights into a trailer weight.

The second weight gives you the "applied" weight on each axle (or group) including distribution effects from the WDH. This will allow you to determine applied hitch weight when level; recognize these weights will constantly be changing as the vehicle moves over the road encountering rises and drops, potholes, etc.

The third weight gives you the hitch weight before effects of the WDH; use this with the second weight to determine actual hitch weight and the load on the WDH as well as the impact on the full rig.

In some cases (like checking axle alignment) if may be necessary to get separate weights on each trailer axle, but I think this is fairly unusual.

Hope that helps.
__________________
Brad & Penny (50 years!)
2017 F350 DRW CC 4x4 Payload=5560
2018 Raptor 353TS
2019 Can Am Maverick Sport XRC - the "Blue Goose"

On YouTube: https://www.youtube.com/channel/UCjc...yZ_w7jyofaPLVQ
LewisB is offline   Reply With Quote
Old 08-22-2020, 09:59 AM   #4
P&DZ
Senior Member
 
Join Date: Oct 2018
Location: Fort Collins
Posts: 125
Thanks LewisB, let me do a better job posting the numbers for yourself and the weight police:

CAT Scale Results
1. Truck + Trailer with Anderson hitch loaded
Steer 3,240
Drive 3,620
Trailer 5,900
Total 12,760

2. Truck + Trailer with Anderson Hitch Unloaded
Steer 3,180
Drive 3,680
Trailer 5,880
Total 12,740

3. Truck Only
Steer 3,480
Drive 2,640
Total 6,120

Truck Specs:
Payload 1,925
GVWR 7,600
GAWR FRT 3,900
GAWR RR 4,300
GCVWR 16,700

Trailer Specs
GVWR 7,200
GAWR 4,400 per axle

Please reference my calculations and questions in the original post.

Thanks.
__________________
2012 Cougar 21RBSWE
2018 GMC 1500 5.3L, 4x4, crew cab, max tow pkg
Andersen Hitch
P&DZ is offline   Reply With Quote
Old 08-22-2020, 10:42 AM   #5
Cyberian
Member
 
Join Date: Apr 2014
Location: Billings MT
Posts: 54
With the WDH difference being so minor between loaded/unloaded, I'm curious what your weights would be without it, and bags if you needed them to keep your headlights pointed where they belong
Cyberian is offline   Reply With Quote
Old 08-22-2020, 01:40 PM   #6
tech740
Senior Member
 
tech740's Avatar
 
Join Date: Jul 2014
Location: Hemlock
Posts: 816
That hitch has the sway control built in so I would say the hitch is still needed. I used to have one and I loved that hitch. Looks like you have 740 pounds available payload once hooked up so that is a good thing. Is the truck and trailer level when set up as you measured it? If not you may want to give the Andersen nuts a twist or two and see if you can level it or put some more weight back on the front axle. Really it looks like you are in good shape but with a little more transfer to the front axle you may feel better planted on the road. Happy Camping
__________________
R.J. and Ginger

2019 Ram 3500 6.7 HO, Aisin Trans 3:73
Reese Goosebox
2019 Sandpiper 379FLOK
tech740 is offline   Reply With Quote
Old 08-22-2020, 03:38 PM   #7
notanlines
Senior Member
 
notanlines's Avatar
 
Join Date: Oct 2014
Location: Germantown, TN
Posts: 6,309
Whatever you decide, do not let anyone convince you that there is no need for a WDH and sway control. You absolutely do.
__________________
Jim in Memphis, Wife of 51 years is Brenda
2019 F450 6.7 Powerstroke
2018 Mobile Suites 40RSSA
2021 40' Jayco Eagle
2001 Road king w/matching Harley sidecar
2021 Yamaha X2 Wolverine 1000
notanlines is offline   Reply With Quote
Old 08-22-2020, 04:02 PM   #8
P&DZ
Senior Member
 
Join Date: Oct 2018
Location: Fort Collins
Posts: 125
No need to worry about me giving up the hitch, what little weight distribution it is providing plus the sway control is worth it. I would like to know why so little weight is being transferred to the front axle. I will attempt tightening the nuts one or two more turns but they are pretty tight at between 4 and 5 teeth showing. Maybe I will give Andersen a call. I have not taken front and rear measurements before and after loading the hitch. From an eyeball perspective both the truck and trailer appear to be level. Certainly the front end is not pointing skyward and it rides fairly well. The other question I had has the 20lb difference in weight between the 1st and 2nd scale weights. Since I did n't add or subtract anything from truck or trailer should they be the same? Is this normal scale error? I calculated the available payload for this particular trip at 508lbs (1925 - 1417), tech740 calculated it at 740, am I missing something?

As always thanks for the help!
__________________
2012 Cougar 21RBSWE
2018 GMC 1500 5.3L, 4x4, crew cab, max tow pkg
Andersen Hitch
P&DZ is offline   Reply With Quote
Old 08-22-2020, 04:09 PM   #9
sourdough
Site Team
 
Join Date: Feb 2014
Location: W. Texas
Posts: 17,601
Here's what I think I'm thinking...

Truck alone = 6120. Truck + trailer = gross 12,760. Trailer = 6640.

Truck alone = 6120 Truck + trailer = (truck) 6860. Tongue = 740

Tongue 740/6640 = 11.1% tongue weight

If I'm understanding the numbers you look to be in very good shape. The one thing I would not do for any reason is leave off the wdh/sway. If you've never set it up with the trailer loaded you may need to tune it a bit but otherwise looks pretty good. At 11% tongue weight I would definitely get it on the road and check it and make sure it doesn't want to wag due to a light tongue.
__________________
Danny and Susan, wife of 56 years
2019 Ram 3500 Laramie CC SWB SB 6.4 4x4 4.10
2020 Montana High Country 331RL
sourdough is offline   Reply With Quote
Old 08-22-2020, 04:34 PM   #10
P&DZ
Senior Member
 
Join Date: Oct 2018
Location: Fort Collins
Posts: 125
sourdough,
Ahhhh...thank you. I was not calculating the tongue weight correctly and therefor coming up with 980 rather than the correct 740. That makes me feel better. So far I have not experienced any wag or sway, even in the steep and winding downhill 6+% grade on I70 in the Colorado mountains. But I do watch my speed. What I do experience is a bit of a truck bounce when going over a bump.
__________________
2012 Cougar 21RBSWE
2018 GMC 1500 5.3L, 4x4, crew cab, max tow pkg
Andersen Hitch
P&DZ is offline   Reply With Quote
Old 08-22-2020, 05:07 PM   #11
sourdough
Site Team
 
Join Date: Feb 2014
Location: W. Texas
Posts: 17,601
The sway control won't help the bounce. There are some things you can do for that.

A 1500 usually comes with P rated auto tires. If that's what you have you can upgrade to LT tires. Did that on my last two 1/2 tons. Replace the shocks with Bilstein 5100 shocks. As new as your truck is I'm not sure they would do what you want them to do. Best choice, and a good one with your situation, is air bags. I used AirLift 1000 bags and they stop the bounce. You do need to watch the inflation pressure loaded and unloaded so it doesn't make the ride harsh. They do not give you more payload (which you don't need) and I don't usually recommend them because that's what folks want them for, but, they will help with your situation.
__________________
Danny and Susan, wife of 56 years
2019 Ram 3500 Laramie CC SWB SB 6.4 4x4 4.10
2020 Montana High Country 331RL
sourdough is offline   Reply With Quote
Old 08-22-2020, 05:25 PM   #12
Wyldfire
Senior Member
 
Wyldfire's Avatar
 
Join Date: Oct 2017
Location: Middleton
Posts: 252
The Andersen will help the bounce. That is one benefit of the urethane bushings. Andersen reccomends 6 threads minimum showing. I find mine works best with 7.
Wyldfire is offline   Reply With Quote
Old 08-22-2020, 06:05 PM   #13
P&DZ
Senior Member
 
Join Date: Oct 2018
Location: Fort Collins
Posts: 125
I do in fact have P rated tires which came as orig equip with the truck. I do plan to upgrade to LT and Bilstein shocks when it is time to replace the tires. In the mean time I will follow Wyldfire suggestion to tighten the Andersen to 6 to 7 threads showing rather than the 4 to 5 I have been applying. The added tension may also transfer more weight to the front tires. The bounce is not severe, mostly a mild aggravation, but if tightening up the hitch does not work I will definitely consider the air bags sourdough recommended.
Attempting to manage further investment this year after 4 new Goodyear Endurance Tires, 2 new Duracell 6v batteries, and replacement equalizers among a few other misc odds and ends.
__________________
2012 Cougar 21RBSWE
2018 GMC 1500 5.3L, 4x4, crew cab, max tow pkg
Andersen Hitch
P&DZ is offline   Reply With Quote
Old 08-22-2020, 07:17 PM   #14
sourdough
Site Team
 
Join Date: Feb 2014
Location: W. Texas
Posts: 17,601
Quote:
Originally Posted by P&DZ View Post
I do in fact have P rated tires which came as orig equip with the truck. I do plan to upgrade to LT and Bilstein shocks when it is time to replace the tires. In the mean time I will follow Wyldfire suggestion to tighten the Andersen to 6 to 7 threads showing rather than the 4 to 5 I have been applying. The added tension may also transfer more weight to the front tires. The bounce is not severe, mostly a mild aggravation, but if tightening up the hitch does not work I will definitely consider the air bags sourdough recommended.
Attempting to manage further investment this year after 4 new Goodyear Endurance Tires, 2 new Duracell 6v batteries, and replacement equalizers among a few other misc odds and ends.


Good for you. It's a learning, growing, spending process. Good luck.
__________________
Danny and Susan, wife of 56 years
2019 Ram 3500 Laramie CC SWB SB 6.4 4x4 4.10
2020 Montana High Country 331RL
sourdough is offline   Reply With Quote
Old 08-22-2020, 07:21 PM   #15
Wyldfire
Senior Member
 
Wyldfire's Avatar
 
Join Date: Oct 2017
Location: Middleton
Posts: 252
More tension will transfer more weight
Wyldfire is offline   Reply With Quote
Old 08-22-2020, 07:25 PM   #16
Wyldfire
Senior Member
 
Wyldfire's Avatar
 
Join Date: Oct 2017
Location: Middleton
Posts: 252
If you haven't watched the install video on Andersen's website you might want to. They use a pretty long socket breaker bar to more easily turn the nuts to the proper tension. Little socket wrenches just don't cut it
Wyldfire is offline   Reply With Quote
Old 08-23-2020, 07:01 AM   #17
P&DZ
Senior Member
 
Join Date: Oct 2018
Location: Fort Collins
Posts: 125
I just re-watched the Andersen video. In the video it is recommended to hand tighten and then further tighten another 4 revolutions of the socket. I will try this approach and see if it results in more threads showing than I had been tightening. I do use a substantial socket wrench but also carry a socket breaker bar on the camper should I need it.
__________________
2012 Cougar 21RBSWE
2018 GMC 1500 5.3L, 4x4, crew cab, max tow pkg
Andersen Hitch
P&DZ is offline   Reply With Quote
Old 08-27-2020, 07:41 AM   #18
john_w
Junior Member
 
Join Date: Jul 2013
Location: Detroit, MI
Posts: 4
To easily get 6-7 threads showing on the Andersen hitch is to use your power tongue jack to raise the trailer and truck up a couple inches. Then tighten up the nuts and then retract the jack. That will load the chains up and at that point it’s much more difficult to tighten or loosen the nuts.
john_w is offline   Reply With Quote
Old 08-27-2020, 01:34 PM   #19
Keystoned
Senior Member
 
Join Date: Jan 2020
Location: abq, nm, usa
Posts: 373
Quote:
Originally Posted by Wyldfire View Post
The Andersen will help the bounce. That is one benefit of the urethane bushings. Andersen reccomends 6 threads minimum showing. I find mine works best with 7.
Yup, I used to have one and 2 things need to happen.
1. the urethane should be squished a bit and
2. that usually happened when about half the nut was visible when tightening with the special socket they provide

If it's not tight enough then might as well not even try...lol

I'm sure more weight was transferred forward but I also had air bags on my truck to get the final level.
__________________
Dan and Rita
Prefer not to be hooked up in a RV park
Keystoned is offline   Reply With Quote
Old 08-27-2020, 08:31 PM   #20
P&DZ
Senior Member
 
Join Date: Oct 2018
Location: Fort Collins
Posts: 125
Thanks for the input. I am definitely going to crank it down to 6 to 7 turns as suggested. I am hopeful this will help the bounce. I won’t know if more weight is transferred to the front axle unless I take it back over the scales.
__________________
2012 Cougar 21RBSWE
2018 GMC 1500 5.3L, 4x4, crew cab, max tow pkg
Andersen Hitch
P&DZ is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by the Keystone RV Company or any of its affiliates in any way. Keystone RV® is a registered trademark of the Keystone RV Company.


All times are GMT -8. The time now is 05:54 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.