Reply
 
Thread Tools Search this Thread Display Modes
 
Old 04-07-2012, 11:45 PM   #1
4 Rivet Member
 
phbarnhart's Avatar
 
2012 25' FB Eddie Bauer
Eugene , Oregon
Join Date: Sep 2010
Posts: 367
Images: 14
Took a trip to the CAT scales

I weighed three times. Once was just the Suburban loaded with stuff but no trailer or hitch (flip the numbers because I pulled into the scales the wrong way), the next was with trailer but w/o any weight distribution and the third was with the weight distribution bars up.



Click image for larger version

Name:	image-1226010889.jpg
Views:	177
Size:	531.5 KB
ID:	155250



Click image for larger version

Name:	image-1610679424.jpg
Views:	151
Size:	521.4 KB
ID:	155251



Click image for larger version

Name:	image-1227624264.jpg
Views:	154
Size:	514.1 KB
ID:	155252
__________________

__________________
phbarnhart is offline   Reply With Quote
Old 04-07-2012, 11:46 PM   #2
4 Rivet Member
 
phbarnhart's Avatar
 
2012 25' FB Eddie Bauer
Eugene , Oregon
Join Date: Sep 2010
Posts: 367
Images: 14
Here's the sticker from the drivers door:



Click image for larger version

Name:	image-444343920.jpg
Views:	132
Size:	524.9 KB
ID:	155253
__________________

__________________
phbarnhart is offline   Reply With Quote
Old 04-07-2012, 11:48 PM   #3
4 Rivet Member
 
phbarnhart's Avatar
 
2012 25' FB Eddie Bauer
Eugene , Oregon
Join Date: Sep 2010
Posts: 367
Images: 14
I know that the weight distribution needs adjusting. I may or may not do it because I've ordered a ProPride and I probably won't be going on any trips before it gets here.

What are your thoughts on the weights otherwise?
__________________
phbarnhart is offline   Reply With Quote
Old 04-08-2012, 10:55 AM   #4
Vintage Kin
 
slowmover's Avatar
 
Corpus Christi , Texas
Join Date: Nov 2006
Posts: 4,422
Images: 1
Good to see this kind of start: tickets and ratings.

By the information offered and no other this would be a crappy riding & towing combination. The RA is overloaded, the TW is too high ("why" needs investigating) and the WD is inadequate.

On this hitch or another we'd also want to see:

1] TV "unladen/solo" scale ticket where the adjusted empty weight is made: driver, full fuel and permanent supplies aboard, but not loaded for camping otherwise.

2] Chevrolet's estimated weight of the vehicle as spec'd

3] Airstreams standard given weight of the TT

4] Pictures of the hitch rigging made while on level ground; and,

5] Pics of the rig from the near distance that frame the "level" or attitude of the rig as a whole.

- Were it me I'd wait for the new PP hitch.

Chevrolet Suburban
Vehicle GVWR: 7,400-lbs
FAWR - 3,600-lbs
RAWR - 4,200-lbs


(The Ron Gratz Chart)

Weighing #1

TT attached and Weight Distribution Activated

Let Front Axle Load be "FA1" 3,000-lbs

Let Rear Axle Load be "RA1" 4,480-lbs

Let TT Axles Load be "TT1" 5,420-lbs


Then, while in same position on scales, take
Weighing #2
TT attached and Weight Distribution Not Activated


Let Front Axle Load be "FA2" 2,840-lbs

Let Rear Axle Load be "RA2" 4,700-lbs

Let TT Axles Load be "TT2" 5,380-lbs


Then, drive off scales and drop TT.

Return to scales and take
Weighing #3

TV only -- TT Not Attached

Let Front Axle Load be "FA3" 3,200-lbs

Let Rear Axle Load be "RA3" 3,360-lbs

6,560-lbs TV gross



From the above values, you can calculate:

TV weight = FA3 + RA3 6,560-lbs

Gross Combined Weight = (FA1 + RA1 + TT1)
- should also be equal to (FA2 + RA2 + TT2) if scale weights are correct

(12,920) = (12,900) [20-lb discrepancy within normal scale range]

TT Weight = Gross Combined Weight - TV Weight

5,380 = 12,920 - 6,560

Tongue Weight = (FA2 + RA2) - (FA3 + RA3)

(2,840 + 4700) - (3360 + 3200), or,
7,540 - 6,560 = TW 980 18%

Load Transferred to TT Axles
when WD System in Activated = TT1 - TT2

5,430 - 5,380 = 50-lbs


Thoughts are that if it rides like crap and doesn't follow well it's because the WDH is just along for the ride at present. TW is too high also.

A] RA is overloaded.

We might expect to see a TW of around 675-lbs to 800-lbs (12.5 to 15%) on a 5,400-lbs TT. When the TV FA is restored to "laden/loaded" solo value, then the RA ought to see from 405 to 600 pounds of TW once WD is activated and optimized.

- In the "laden/towing" ticket we want to see the same FA as when "laden/solo" for the TV. (It is heavy by 160-lbs).

- In the ticket showing WDH activated, we would want to see a RA of closer to 690-lbs additional, and a TT weight of 290-lbs additional in a 70/30 split of TW from TV to TT (and that could also be 75/25 or 60/40, etc).

1] Why the TW is at 18% needs investigating

2] Adjustments to the hitch need to "return" FA to unladen value

3] Adjustments to the hitch need to correspondingly "transfer" more TW to the TT axles.

My action plan (were this mine) would be about tire capacities (TV & TT; where a margin of 15% adheres for all loads). A 4200-lb rating, with a likely 90% load factor when all is said & done, means we'd want to know the exact per tire loading. What is the tire manufacturer load rating?

Then, why TW is so high (several hundred pounds). A trailer of this size shouldn't push margins so much. Was something added or loaded to truck rear? Something in the forward 20% of the TT?

.
__________________
1990 35' Silver Streak Sterling; 9k GVWR.
2004 DODGE Cummins 305/555; 6-manual; 9k GVWR.
Hensley Arrow. 15-cpm solo, 25-cpm towing
slowmover is online now   Reply With Quote
Old 04-08-2012, 12:14 PM   #5
Vintage Kin
 
slowmover's Avatar
 
Corpus Christi , Texas
Join Date: Nov 2006
Posts: 4,422
Images: 1
Since the new hitch isn't available, might as well verify tire loadings and proper pressures:

A Suburban K10906 is a half-ton 4WD. Did it come with the 20" tires? Is it Z71 spec?

The OEM tire would have then been GY or Bridge in 275/55-20 with a Load Index of 111, or, 2,400-lbs each (4,800 combined).

To bring it 15% past RAWR would be 4,800-lbs (same as factory).

Other tires would bring it to an Index of 117 or 2,900-lbs ea in the 20" sizing (5,800-combined) an 18% increase past factory (certainly no more needed).

Not saying that the TV needs other tires. But if combined weights stay high on loadings, this is the suggested course to start with.

A per-wheel position scale ticket -- X4 -- would be good where the TV is loaded as heavily/highly as is ever likely. Per axle averages are good where the margin is not approached (in general) but ought to be mandatory when it is. One wheel or another may be 20-30% higher than the other on the same axle thus the load margin is needed per that position.

We can use the initial TW loadings to speculate about the likely range of weights seen on each wheel if we can get per-wheel weights, etc.

Hereis a recommended professional tire pressure gauge (with case). One for TT and one for TV (keep case with dedicated TQ wrench for TT wheel lugs). Always a spare.

A highly accurate gauge such as this allows one to set both TT & TV tire pressures with any air source with consistent reliability.

1] TT tire pressure should always be at sidewall maximum (10% higher for extended parking, but adjusted down for movement).

2] TV tire pressure is a bit time consuming (first time, like WDH adjustment) but we want no more than about 5-psi rise in pressure after 1.5-hr of steady state driving. Raise or lower in 5-psi increments until the lowest best value is acheived for the TV load at that time where factory upper/lower limits are respected, and the FF/RR psi balance remains.

I know it sounds like too much. But living in hurricane country makes one aware that nothing may remain of ones home. And that no area of the country is exempt from this scenario type. The advantage of a truck pulling a travel trailer is that one just might load the kitchen sink. Thus the wheel weights, individually, is the manner of determining if TV tires should be upgraded (the cost justified) if the margins suggest that this is advisable.

A survey -- in this way -- covers all contingencies.

.
__________________
1990 35' Silver Streak Sterling; 9k GVWR.
2004 DODGE Cummins 305/555; 6-manual; 9k GVWR.
Hensley Arrow. 15-cpm solo, 25-cpm towing
slowmover is online now   Reply With Quote
Old 04-08-2012, 12:44 PM   #6
4 Rivet Member
 
phbarnhart's Avatar
 
2012 25' FB Eddie Bauer
Eugene , Oregon
Join Date: Sep 2010
Posts: 367
Images: 14
Thanks Rednax, you've pretty much confirmed my suspicions regarding this particular setup. I guess that I probably got used to it handling like crap because I don't really know any better.

The tires are already upgraded 117 load range. Nokian Vativa, if your curious.

The back of the Suburban had the little Weber Q BBQ, the two cocker spaniels and the Honda 2000i generator in it with the third row of seats removed and all the stuff (BBQ and genny) pushed up as far towards the front as they would go. Essentially they were right over the rear axel.

I should also point out that, the fresh water tank was a little less than half full so consider that there's another 160lbs in the trailer. My driveway is an such an angle that I cannot fill the fresh tank at home.

Even though the Suburban is painfully new I've been talking to the local dealer about a 3/4ton model. I'm towing with my two little boys in the car and the way things are now (even with a ProPride and perfect W/D) I'm right on the edge of my current vehicle's capacities.
__________________
phbarnhart is offline   Reply With Quote
Old 04-08-2012, 12:55 PM   #7
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 15,849
Images: 1
Quote:
Originally Posted by phbarnhart View Post
I weighed three times. Once was just the Suburban loaded with stuff but no trailer or hitch (flip the numbers because I pulled into the scales the wrong way), the next was with trailer but w/o any weight distribution and the third was with the weight distribution bars up.



Attachment 155250



Attachment 155251



Attachment 155252

Your towing weights are way out of line.

You can clearly see that when you tow, the front axle has less weight on it. VERY BAD.

To be safe the maximum difference of weights between the front and rear axle, should be no more than 10 percent.

However, the closer the front and rear axle weights are are, the better.

Keep in mind that a good load equalizing hitch, properly installed and properly adjusted, will also move some of the weight in your tow vehicle.

Ideally, when your rigged up, the front axle should weigh 3660, and the rear axle should weigh 3820.

However, never let it become worse than 3350 on the front axle and 4130 on the rear axle.

If those weights are not as listed, then basically your load equalizing hitch is useless for towing.

Be safe, follow the rules, and observe the far better handling.

Andy
__________________
Andy Rogozinski
Inland RV Center
Corona, CA
Inland RV Center, In is offline   Reply With Quote
Old 04-08-2012, 01:08 PM   #8
NA

 
2003 25' Classic
Zanadude , WNY
Join Date: Jun 2007
Posts: 9,000
Images: 1
phbarnhart,

...I would try for at least 260lbs more on the steering axle regardless of hitch being used. Your goal is to replace the lost str axle weight between ticket #1 and #3, keeping the entire rig level.
The hitch choice won't correct light steering.

Bob
__________________
ROBERT CROSS is offline   Reply With Quote
Old 04-08-2012, 01:55 PM   #9
4 Rivet Member
 
phbarnhart's Avatar
 
2012 25' FB Eddie Bauer
Eugene , Oregon
Join Date: Sep 2010
Posts: 367
Images: 14
Bob and Andy,

Thanks for the input. I agree that the w/d is not working as it should. I've ordered the ProPride primarily because of the sway elimination but also because the weight distribution system seems much easier to adjust. I am concerned that it will add at least 100 lbs to the tongue. I guess that will just get distributed and not matter too much.
__________________
phbarnhart is offline   Reply With Quote
Old 04-08-2012, 03:58 PM   #10
Vintage Kin
 
slowmover's Avatar
 
Corpus Christi , Texas
Join Date: Nov 2006
Posts: 4,422
Images: 1
Yeah, theres room to work with on weights, no question. Glad to see TV tires are not at question for load capacity (so playing with pressure is just SOP). TT tires are worthy of the same per-wheel investigation (also at full load). TW . . . . ?

Get those first five bits of requested info (numbers & pics) as convenient, and the next go-round will have any/all questions framed in.

.
__________________
1990 35' Silver Streak Sterling; 9k GVWR.
2004 DODGE Cummins 305/555; 6-manual; 9k GVWR.
Hensley Arrow. 15-cpm solo, 25-cpm towing
slowmover is online now   Reply With Quote
Old 04-08-2012, 06:27 PM   #11
Rivet Master
 
dznf0g's Avatar

 
2007 30' Classic
Oswego , Illinois
Join Date: Jul 2010
Posts: 5,780
Quote:
Originally Posted by phbarnhart View Post
Bob and Andy,

Thanks for the input. I agree that the w/d is not working as it should. I've ordered the ProPride primarily because of the sway elimination but also because the weight distribution system seems much easier to adjust. I am concerned that it will add at least 100 lbs to the tongue. I guess that will just get distributed and not matter too much.
Keep in mind that if you weigh the tongue on, say, a Sureline, with the PP attached....yes you will add about 100# to tongue weight. BUT, with the vehicle hitched up, the PP adds about 100#s to the rear axle weight but NOTHING to tongue weight. Think about it for awhile and you'll get it.
__________________
-Rich-

"If the women don't find you handsome, they should at least find you handy." - Red Green
dznf0g is online now   Reply With Quote
Old 04-08-2012, 09:31 PM   #12
2 Rivet Member
 
Currently Looking...
Western slope , Colorado
Join Date: Jan 2010
Posts: 90
Quote:
Originally Posted by dznf0g

Keep in mind that if you weigh the tongue on, say, a Sureline, with the PP attached....yes you will add about 100# to tongue weight. BUT, with the vehicle hitched up, the PP adds about 100#s to the rear axle weight but NOTHING to tongue weight. Think about it for awhile and you'll get it.
So...with a weight distribution hitch, does original tongue weight even matter? I don't get your statement. The mass of the hitch is still there only the springs(bars) torque the system applying downward force to the tv front axle and the rv's axles in essence applying a bending moment with the fulcrum at the hitching point. You are not moving mass/weight, just redistributing load/force.
__________________
"If you come to a fork in the road, take it."
Yogi Berra
Streamside is offline   Reply With Quote
Old 04-08-2012, 09:40 PM   #13
Rivet Master
Airstream Dealer
 
Inland RV Center, In's Avatar
 
Corona , California
Join Date: Feb 2002
Posts: 15,849
Images: 1
Quote:
Originally Posted by Streamside View Post
So...with a weight distribution hitch, does original tongue weight even matter? I don't get your statement. The mass of the hitch is still there only the springs(bars) torque the system applying downward force to the tv front axle and the rv's axles in essence applying a bending moment with the fulcrum at the hitching point. You are not moving mass/weight, just redistributing load/force.
A load equalizing hitch, redistributes tongue weight.

That weight total is from the weight of the tongue, the hitch weight, AND, the truck or rear axle extra load weight.

If a pickup truck, as an example, has a payload in it's bed, the load equalizing hitch can and does move some of it as well.

The hitch torsion bars have no idea where the weight is from, and doesn't really care. It's job is to "move it", to some degree.

Andy
__________________
Andy Rogozinski
Inland RV Center
Corona, CA
Inland RV Center, In is offline   Reply With Quote
Old 04-08-2012, 09:54 PM   #14
4 Rivet Member
 
phbarnhart's Avatar
 
2012 25' FB Eddie Bauer
Eugene , Oregon
Join Date: Sep 2010
Posts: 367
Images: 14
You guys are making my head hurt. Are we getting metaphysical about tongue weight v. axel weight?
__________________

__________________
phbarnhart is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bathroom walls have some damage to the bottoms, can't think of good repair. mikeandnora General Interior Topics 5 04-10-2012 06:36 AM
Does anyone know where to get Parbond in Canada? TPickerl Leaks - Weatherstrips, Gaskets, Caulks & Sealants 8 04-09-2012 10:17 AM
Chevy Avalanche & 71 Sovereign LY 31' Road Trip africaroots Towing, Tow Vehicles & Hitches 5 04-08-2012 12:14 AM
Is there a way to test the power converter? Taylormade Batteries, Univolts, Converters & Inverters 8 04-07-2012 09:36 PM
Airstream Overlander 26' ready to customize or restore. No Reserve Auction!!! eBay Watch Airstreams on eBay 0 04-07-2012 07:40 PM





All times are GMT -6. The time now is 10:01 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.
Modal Click