Cabriolet86
Rochester, MN
Senior Member
Joined: 09/16/2006
View Profile
 Offline
|
Turning while driving forward isn't your only enemy. Any rises or dips in the surface that the truck and/or trailer on will hurt you. My father in law put out a back window driving forward while coming down a steep hill and having to make a tight right hand corner at the bottom.
|
mapguy
Puget Sound
Senior Member
Joined: 09/02/2007
View Profile
Offline
|
Cabriolet86 wrote:Turning while driving forward isn't your only enemy. Any rises or dips in the surface that the truck and/or trailer on will hurt you. My father in law put out a back window driving forward while coming down a steep hill and having to make a tight right hand corner at the bottom.
Bingo we have a winner!
Uphill or downhill cutback turn on uneven ground is the recipe for severe cab damage in a short bed application without a slider being deployed -manual or automatic.
Map Guy
|
Vulcaneer
Northern New England
Senior Member
Joined: 10/17/2007
View Profile
Offline
|
calliopeguy wrote:
So question #1 is:
You cannot PULL yourself into a 90 degree turn - True/False.
Question #2 is:
If you have a shortbed truck, you cannot turn sharp enough to cause damage while driving forward - True/False
Calliope. Your questions are valid. But the answers are not that simple. As different conditions, cause different answers.
Question 1 is FALSE. You CAN pull yourself into cab damage. Try pulling into a 180 U turn and you will see. This will create a 90 degree TV/Trailer angle.
However if you are asking if you can make a 90 degree turn from intersecting streets, you may be OK. Your TV probably has a steering angle of 37 degrees or so. So making a 90 degree turn to perpendicular streets, should theoretically not be a problem. As previously posted, the interference point is usually around 55 degrees. An extended pin box will help this clearance angle somewhat. But road dips can change all that theory under the wrong conditions.
Question 2 is also FALSE. You CAN turn sharp enough while driving forward, to cause damage. But it is the total turn angle that makes the difference. If the turn is 90 degrees, with an extended pin box, probably OK. But if turning a tight 180 degree U turn as on a cul-de-sac, or in a parking lot, the trailer corner will take out the cab or window. If you need to make a U turn in a parking lot, make it a very wide turn to avoid the cab/trailer collision.
Finally a word of caution for those with rounded corners on the trailer. If making a tight U turn, and half the width of your trailer is wider than the distance from the kingpin to your cab, you can get interference when making a tight 180 turn. The rounded corners are a great benefit. But they don't always protect at all times.
* This post was
edited 07/09/08 10:04am by Vulcaneer *
2006 F350 V10 4X4 SC SB SRW 4.30 22,500 GCWR
Keystone Sprinter 33'9" 12,500 GVWR
Pullrite Super Glide 18K
Super Duty, Super Cab, SuperGlide
|
kennethwooster
Perryton Tx USA
Senior Member
Joined: 11/21/2003
View Profile
Offline
|
I'm a witness that it can be turned sharp enough to take out the rear window on a shortbed. My rear window had to be replaced, and thus a Super Glide hitch. All this happened with a Mor Ride Extended pin box that came on the trailer
kenneth wooster- farmer
wife Diana-adult probation officer
365BSQS Quad slide 2007 Quantum
Ford F350 2005 model, 4X4 FX, King Ranch
18K SuperGlide Hitch
|
Butch50
NW Montana
Senior Member
Joined: 06/29/2002
View Profile
|
It has not happened to me but I also have a SuperGlide, but I have a friend (this is not a friend of a friend's BIL knows someone that told him this) but a friend that originally didn't think he needed a slider will after a few trips and he had some dents in the top of his cab from contact with the 5er front but never lost a window. So then he got a manual slider and the RV place said he would never have to slide it back going forward. Wrong, he was pulling out of a filling station and turning hard left and the drivers side rear tire on pickup fell into pothole and just that quick his back window was gone. His poor dog refused to ride in the back seat for a long time after that. So it took a long time to answer question #2 but yes you can break them out going forward. Now it also depends on your pin extension and the shape of your front in the 5er.
Butch
2006 F550 CC 4X4 Lariat PSD/Torqshift Dark Shadow Grey Metalic w/Manning F350 bed
2009 Excel Limited 30TKE
2009 Arctic Fox 1140 (On Order due February)
2006 Dodge 3500 Laramie 4X4 QC SB SRW/Cummins 6 speed Jake exhaust brake
|
|
|
DSteiner51
Wooster, Oh
Senior Member
Joined: 01/30/2004
View Profile
|
On my 5th wheel trailer (converted to gooseneck) I can hit the cab easy while only going forward. On my gooseneck equipment trailer while going forward I can turn the tv hard enough that the equipment trailer will start backing up while truck is still going forward. It depends on the turning radius of the tow vehicle/length of trailer combination.
For me the answers are definitely; False and False.
D. Steiner
|
JIMNLIN
Big Cabin, OK
Senior Member
Joined: 09/14/2003
View Profile
|
#1. the question is vague. My short bed Dodge cannot turn 90 degrees to my 5er when pulling forward but can make a 90 degree turn/cornor. Any truck/trailer combo can turn a 90 degree cornor but may not be able to get the truck 90 degrees to the 5er while pulling forward.
#2. false for my combo as my 5er will hit the cab on hard turns without using the slider
'03 2500 Dodge/Cummins HO 3.73 6 speed manual Jacobs
'97 Park Avanue 28' with two slides
|
Dayle1
Spicewood, Tx
Senior Member
Joined: 04/12/2001
View Profile
Offline
|
As someone already stated, the truck's steering angle is about 37 degrees. With a little math, wheelbase and curb-to-curb turning radius, anyone can verify this for their own vehicle. Motorhomes, MDTs and above have 55 to 60 degree steering cuts. Everything else is less than 40 degrees.
If the pin to fiver axle distance is roughly the same distance as the tv's wheelbase, then the fiver will pretty much track the tv thru a complete 180 degree U-turn. However the fiver will turn slightly inside the tv due to tire slip of the tandem axles and the wider axle of the fiver. If the fiver has an extended pin box, then a cab to fiver angle of about 60 degrees is pretty typical and even if the fiver distance is longer than the tv's wheelbase a 180 U-turn can safely be done. If the fiver does not have an extended pin box, then it's a different ball game with a shortbed tv.
Semi's have a much shorter tractor wheelbase compared to the trailer length and therefore significantly different U-turn characteristics.
So to #1, it is true, with a typical pickups wheelbase and the typical length of a fiver, you cannot get the fiver at 90 degrees to the truck while executing a 180 degree U-turn. Without an extended pin box (or a slider hitch) you might get cab to fiver contact, but the combo will NOT be at 90 degrees.
* This post was
edited 07/09/08 03:11pm by Dayle1 *
Larry Day
Texas Baptist Men-Retiree Builders since '01
'03 GMC 2500HD D/A EC SB, Jordan controller, custom RKI bed/hitch, Putco boards, TF 45gal tank, grey Speedliner
'04 CrossRoads Cruiser CF29RK, Mor/ryde IS, Carefree Eclipse 12V awning
Rig Photos
|
mapguy
Puget Sound
Senior Member
Joined: 09/02/2007
View Profile
Offline
|
You know it is important to focus on the issues being discussed as they apply in the real world for a fifth wheel driver...not as a technical paper problem to solve.....several posters have talked about "angles" a great deal but bottom line is that a short bed pickup truck towing a fiver has a "potential" cab impact zone during maneuvers due to Pin to cab dimension - traveling conditions -level pavement/off road / dips and on and on, plus exact equipment involved and how it is set-up make this "potential" cab impact zone a "moving target" in relationship to the two questions.
1. False -Yes you can -do a u turn in a culdesac -have done this with tractor lowboy in residential subdivisions a lot -it kills tires but sometimes is the only way unless you want to back up for a long distance with poor line of sight
2. False -but is somewhat dependant on PIN to cab dimension and ground conditions and equipment for the actual angle of impact / whether greater or less than the mystical 90* figure
As a driver in traffic do you analyze -while maneuvering - whether or not it is a 90* turn (on paper)truck to trailer or that the road intersects at a 90* angle or a 88* angle to your destination - IMO most do not -they focus on making sure no accident happens to cause injury to life or property......
Happy trails
Map Guy
|
mapguy
Puget Sound
Senior Member
Joined: 09/02/2007
View Profile
Offline
|
opps
|
|
|
