Reply
 
Thread Tools Search this Thread Display Modes
 
Old 08-20-2015, 09:39 AM   #1
Uncle Shelly
 
Gshellhammer's Avatar
 
2001 25' Safari
Lakeview , Ohio
Join Date: May 2014
Posts: 10
Tow vehicle performance after change in TV cargo

Just returned from a trip to Arkansas. While there decided to replace TV tires. I was very happy with my setup and performance that I just tried to replace with identical tires. Tires were replaced just prior to returning home.

Data: TV - 2010 Grand Cherokee hemi with towing package. Trailer 2001 25ft Safari AS sleeper6. Original tires Goodyear Fortera HL 245/60r18. New tires are Goodyear Wrangler SR-A 245/60R18 Load/Speed rating 105T. OEM tire pressures suggested 33lbs. Put 38lbs. in new tires. Max tire pressure on tire sidewalks is 51lbs. Reese hitch with trunnion style WD bars. No sway control. Ball is set 3/4" above coupler before load. After load front measurement at front TV axle does not drop. After load rear TV axle drops 1.5".

So immediately after leaving with new tires I noticed a dramatic difference in sway. Not only did large semis suck me in but small pickups also caused a pull. This was a dramatic change. Completely rechecked my hitch settings since I had new tires. All measurements were the same. Decided to increase tire pressure to 44lbs as my original tires were maxed out at 44lbs. After driving about 50 miles on freeways, I felt that the sway was somewhat better but internet advice from various websites reiterated following OEM suggested pressures. I stopped at a rest area and dropped the pressure back to 38lbs. So I fought the swaying all the way through Atlanta.
As we got north of Atlanta, I realized that there was another change in my TV. I did not bring my Toolbox. I needed the room for a number of boxes of china. And those boxes were now gone. They went at the same time we put on the new tires. So at the stop for lunch I grabbed our trays of canned goods stored under the dinette and moved them into the TV.
The result was just as dramatic. Gone were the scary semi truck pulls. Gone were the pickup truck pulls. Now I could start to enjoy the drive.
We have been traveling the Eastern U.S. For the past year and a half. I just realized that I always have brought a toolbox.

So my question is this. Why would 50-75lbs in the back of my Grand Cherokee make that much difference? And what can I do about it for the future? If I shorten the WD hitch with one less link and nose down the front of the TV help?

Your advice will be greatly appreciated.
Gshellhammer is offline   Reply With Quote
Old 08-20-2015, 09:56 AM   #2
CLOUDSPLITTER "Tahawus"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , Milky Way
Join Date: Jun 2007
Posts: 16,047
Images: 1
Question Confused....

"Reese hitch with trunnion style WD bars. No sway control."

75lb shouldn't make that much of a difference.....no sway control would?

The reviews on those tires are 3 out of 5....why were they chosen?

Bob
ROBERT CROSS is online now   Reply With Quote
Old 08-20-2015, 10:04 AM   #3
4 Rivet Member
 
Tuco's Avatar
 
1988 32' Excella
Ojai , California
Join Date: Aug 2014
Posts: 275
Images: 1
I had a similar experience with new TV tires. Solid as a rock before and squirrely after. It had nothing to do with load in our case. It took time for the new tires to square themselves off. It was like the truck was on the "balls of its feet". After about 300 miles the truck was back to normal, but wow that 300 miles was rough!
__________________
Dave & MJ
1988 32' Excella 1000 (Beauty)
1999 White Dodge SLT Laramie 3500 Dually, 4x4, 5spd, 5.9 CTD 265k+ (The Beast)
Tuco is offline   Reply With Quote
Old 08-20-2015, 10:20 AM   #4
Uncle Shelly
 
Gshellhammer's Avatar
 
2001 25' Safari
Lakeview , Ohio
Join Date: May 2014
Posts: 10
Why were they chosen? They were suggested by the tire dealer. I was away from home. Not an excuse just a reason. The change that occurred was dramatic. I felt the change within five miles from the rest area's on ramp. It only took a couple of truck passes to to tell my wife that things were better.
Gshellhammer is offline   Reply With Quote
Old 08-20-2015, 10:31 AM   #5
Rivet Master
 
AWCHIEF's Avatar
 
2006 23' Safari SE
Biloxi , Mississippi
Join Date: Nov 2011
Posts: 8,278
Images: 33
On my 2011 JGC Hemi I went from the OEM stock tires to Bridgestone Dueller H/L, P265/50R20. Really dramatic improvement in handling and feel. I run them at 39lbs. These tires are highly recommended on the Jeep Forums for towing and all around use.
__________________
MICHAEL

Do you know what a learning experience is? A learning experience is one of those things that says "You know that thing that you just did? Don't do that."
AWCHIEF is offline   Reply With Quote
Old 08-20-2015, 02:39 PM   #6
CLOUDSPLITTER "Tahawus"
 
ROBERT CROSS's Avatar

 
2003 25' Classic
Zanadude Nebula , Milky Way
Join Date: Jun 2007
Posts: 16,047
Images: 1
Thumbs up

Concentrate on the tires when there is no sway control?.....

Just what I would do, set PSI to the max sidewall value or just a bit less, add sway control and visit the scales to get the proper WD set-up.

But that's just me.....

Bob
ROBERT CROSS is online now   Reply With Quote
Old 08-20-2015, 04:12 PM   #7
Rivet Master
 
Currently Looking...
Mission , Texas
Join Date: Jun 2015
Posts: 836
Take the TV tires up to 50 psi and see what you think.
Our F250 is squirrely when the tires are low.
nrgtrakr is offline   Reply With Quote
Old 08-21-2015, 05:59 AM   #8
Uncle Shelly
 
Gshellhammer's Avatar
 
2001 25' Safari
Lakeview , Ohio
Join Date: May 2014
Posts: 10
I plan to increase the tire pressure to 50 psi and test drive our local freeway. I will report back here with the results.
Gshellhammer is offline   Reply With Quote
Old 08-21-2015, 10:01 AM   #9
2 Rivet Member
 
1972 23' Safari
Norwalk , Connecticut
Join Date: Sep 2014
Posts: 60
Is your dinette in the front or rear of your trailer. I recently had about 100# extra in the rear of our trailer an it felt similar to how you described. Weight out on the next trip and all was cool. In my case I believe we are on the edge of low tongue wt. I haven't checked with a scale.

I'll second the tire wear in as well. Last time I got new treads they were particularly squirmy for the first week or so. Then settled right in.

Add the canned goods back to the trailer and see if you can repeat.
Widget is offline   Reply With Quote
Old 08-21-2015, 12:02 PM   #10
2 Rivet Member
 
Paul and Tam's Avatar
 
1988 34.5' Airstream 345
Ham Lake , Minnesota
Join Date: Aug 2005
Posts: 60
One thought - You may have selected the wrong load range for your usage of the vehicle. I noticed that the tires you bought are 105T load rating, or SL. Take a look at your sidewall to see the maximum load capacity for this tire. My guess is that you are running near that load on the rear axle when you have the trailer attached. 50PSI will help, and I recommend running the fronts at 50 as well for weight transfer during braking.

The last tire change on our tow vehicle (horse trailer, not camper) I went with XL rated tires for the higher load rating. My wife's initial complaint was that the TV drove more like a truck. That was true - the stiffer sidewalls did not absorb little bumps as well as the p-metric tires that were previously on her SUV, but the load rating per tire went from 1600 to 2200 lb. I like having 1200 lb of safety on the rear axle when the TV is used as a truck.

Good luck, and I hope running at 50psi helps.
Paul and Tam is offline   Reply With Quote
Old 08-21-2015, 06:10 PM   #11
Uncle Shelly
 
Gshellhammer's Avatar
 
2001 25' Safari
Lakeview , Ohio
Join Date: May 2014
Posts: 10
Thanks, I will look at my options. If the increase in psi fixes the problem and I am not exceeding load capacity of the tires, I will let you know the results. If I made a $1000 mistake, I will fix it.
I thought I did things right.
Gshellhammer is offline   Reply With Quote
Old 08-21-2015, 06:18 PM   #12
Uncle Shelly
 
Gshellhammer's Avatar
 
2001 25' Safari
Lakeview , Ohio
Join Date: May 2014
Posts: 10
Widget, the dinette is in the middle. My heavy weight is almost directly over the axles. I will be trying the movement of the weight.
Gshellhammer is offline   Reply With Quote
Old 08-21-2015, 07:18 PM   #13
Rivet Master
 
1996 25' Excella
Tillsonburg , Ontario
Join Date: Aug 2014
Posts: 1,122
"50PSI will help, and I recommend running the fronts at 50 as well for weight transfer during braking. "


I'm not sure you want to run front tires at max. You need max pressure on rear for load and running cool but front tires at max unless you really transfer a ton of weight forward will give you poor steering control. High pressure without weight will round out the tire and wears center faster....so less foot print under the front suspension. Certainly there is some dive under hard braking, but the equalizers tend to keep the truck even front to back even under heavy braking.

JCW
JCWDCW is offline   Reply With Quote
Old 08-21-2015, 08:04 PM   #14
Rivet Master
 
Bowmans's Avatar
 
1979 31' Sovereign
1950 22' Liner
Powhatan , Virginia
Join Date: May 2009
Posts: 521
Blog Entries: 52
I wouldn't run without a sway control myself. The risk is always there for a good side wind, whether from a large semi or winds.

We run an F150 with a 31' 1979. I can tell the difference when I move 40# from the trailer center to the bed of the truck. I have gotten the load down now to where I can tell whether we are light in the truck bed or front of the trailer and will stop at the first rest area and shift a little. Have you put the box back in the TV and tried out that additional weight with the new tires?
__________________
Tadd, Beth, Grundgetta and Weeble
Our blog
Proud to be Air #37137
Bowmans is offline   Reply With Quote
Old 08-21-2015, 08:51 PM   #15
Vintage Kin
 
Fort Worth , Texas
Join Date: Nov 2006
Posts: 8,014
Images: 1
Tires need a few thousand miles to settle in. This explains the most.

Rig still needs to have WD set on a scale. Fender measurements are a good rough-in, but that's all. Tire slop makes less than ideal WD more obvious.

TV tire pressure needs to be according to load and within door placard range. TT tires at sidewall max.

Best to get individual wheel loads on TV with WD applied in order to set best cross axle tire pressure.

Get these mechanical details attended to before deciding about tires choice.

I never liked the SR-A but it may have changed since 2001. Reading forums and Tire Rack reviews for those with more than 20k on tires is a good idea (as in above post).

Better shock absorbers always a good idea unless what's on there is some high zoot factory type. BILSTEIN, unless KONI available.
slowmover is offline   Reply With Quote
Old 08-24-2015, 05:04 PM   #16
Uncle Shelly
 
Gshellhammer's Avatar
 
2001 25' Safari
Lakeview , Ohio
Join Date: May 2014
Posts: 10
First let me say thank you for all your inputs. If I have learned anything from this experience, it is that there is a wealth of information on the Internet about setting up a WD hitch for a TV. But not everything is standardized. Often the information is debatable and varies with the experience of the contributor.
So I have taken in everything I can and then tested as I could.
I can and maybe will take my rig to a weight scales to get each axle or even each wheel weighed. But I am going to have to find a professional who knows how to interpret those numbers.
I can turn a wrench. And I can apply complex formulas to get answers. But using those numbers correctly is frustrating. I have calculated axle weights, gross TV weights, gross TT weights, etc.
Mathematically, I did not exceed the load factor of my tires. I have over 300 lbs on each tire to play with. I doubt I can stuff my motorcycle in the trunk. So, I will not be purchasing another set. But I would never recommend them.
So I took the trailer for a ride. I pumped up the new TV tires to 50# a pound less than max. I drove it on a windy day without excess weight in the back. The movement of the trailer was expected. Then I stopped and shortened the number of links by one. It did not help and I felt less in control. So we stopped again and lengthened the chain links and moved weight to the back of the TV. I know this is not explainable but the vehicle felt heavier. As if I was more in control.
So results of my non-scientific and non-quantitative experiment. I will leave my tires pumped to max and always travel with my tool boxes (120lbs). If I run into a professional TV rigger, I'll get a price quote.
Gshellhammer is offline   Reply With Quote
Old 08-24-2015, 05:52 PM   #17
Rivet Master
 
Currently Looking...
Mission , Texas
Join Date: Jun 2015
Posts: 836
Very good! Thanks for the update!
nrgtrakr is offline   Reply With Quote
Old 08-24-2015, 06:37 PM   #18
Rivet Master
 
1974 Argosy 20
2014 20' Flying Cloud
Kooskia , Idaho
Join Date: Jul 2009
Posts: 4,591
This is probably of no use but my 2012 Jeep Grand Cherokee Overland with full air suspension came with Michelin 265/50 R20's. When they got worn down they wanted to hydroplane when it rained, so at about 30,000 I replaced them with the identical tire. I noted no change at all in towing (I do a lot), still very stable and solid, with absolutely no indications of any sway. The trailer is either a '74 Argosy 20' or a '14 FC 20. The hitch is an Andersen.

I have noted no towing difference if the water or holding tanks are full or empty, they are all behind the axle in the FC 20. In the Argosy the 35 gal water tank is up front. In other words, I have noted no change due to weight shift and distribution.

I have read of tires making a lot of tow stability difference, and you seem to have proved that possibility out. However I have no ideas or opinions as to why it should have happened to you with your combination. Is there any chance your tire dealer will exchange them for some other brand, given your experiences? I doubt that you will find a good solution by either tire pressure changes or moving things around. I would not want to drive a combination which was that sensitive at any rate. It would seem to be on the edge all the time.

I will be interested in how this plays out for you.
idroba is offline   Reply With Quote
Old 08-27-2015, 03:11 PM   #19
2 Rivet Member
 
Paul and Tam's Avatar
 
1988 34.5' Airstream 345
Ham Lake , Minnesota
Join Date: Aug 2005
Posts: 60
Thanks for the updates. I'm glad the extra pressure helped, and sorry it did not fix the problem.
One question, and no offense intended, but are the trailer tires all inflated to the same pressure?
We've experienced some decreased stability with a low tire on the horse trailer. Trust me, you so not want to have a blow out at highway speeds.
Paul and Tam 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
Possible last minute change - new (used) tow vehicle for 25' Excella JustSomeGuy Towing, Tow Vehicles & Hitches 90 12-31-2014 02:20 PM
Poor brake performance. Even after new brakes. timmaah Brakes & Brake Controllers 64 08-25-2013 09:08 PM
Change tow vehicle bluvalley 2002 - 2005 International 23 01-05-2006 12:49 PM
Change wheel drum to match tow vehicle Rick Alston Axles 7 01-22-2004 06:26 PM
Towing Vehicle Performance Modifications docbluedevil Tow Vehicles 32 11-10-2003 05:31 PM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



All times are GMT -6. The time now is 07:54 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.