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gordonpoole
09-15-2009, 10:56 PM
I have a Chev short box and have the hitch centered over my back axle. This doesn't give me a sharp enough turning radius without the trailer hitting my back window. Is there a problem moving the hitch back 4"?

billr
09-16-2009, 09:21 PM
The hitch has to be centered on the axle CL. Actually it should be 1" fwd of the Axle CL. No way should you move it back on a Pickup. It will pull wt off your front axle and cause some very bad handling.

You will have to keep a close eye on your turns and when backing.

We towed with a SB Chevy for 4 yrs with no slider and no issues. Have to watch it though.

Another option is a sliding hitch. There are manual types you have to stop and get out and pull a lever to slide them back and same to reset fwd for driving. These are only for parking etc, no driving. Problem with these is you HAVE to use it, if you forget, wham! Lots of mashed up truck windows on trucks with sliders and forgot to pull them.

There is also a hitch that is automatic. Is a bit higher cost. It always moves back when a tight turn is started and returns to normal when straight.

Bill

wingnut60
09-17-2009, 11:18 AM
As billr says--don't move the hitch rearward, it will leverage weight OFF the front axle and result in squirrely handling. PullRite Superglide is usually the answer; Reese has a manual slider, several others also.
If you go manual, you HAVE to remember to release the slider before turning.
Joe

gordonpoole
09-18-2009, 06:03 PM
Thanks for the replies from both Bill and Joe. I ran my problem by two engineers and they calculated that I lost 18lbs off my front end for every inch I moved the hitch back from centre (not compounded). I'm not sure how much of a problem that would cause, but I'm looking into a automatic slider.
Gord

Motor31
09-19-2009, 10:43 AM
The hitch manufacturer has already done most of the calculations for you. The mounting instructions should show where the hitch is to be mounted.

It's not likely you will get a fixed amount of weight transfer per inch as you have to figure the pin weight of the trailer into the calculations. Heavier trailers add more weight and if you move it back you'll be in the same position as a bumper pull that is too heavy for the truck. The 5th wheel trailer will put between 10% to 20% of it's weight on the tow vehicle.

Stripit
09-19-2009, 11:39 AM
Thanks for the replies from both Bill and Joe. I ran my problem by two engineers and they calculated that I lost 18lbs off my front end for every inch I moved the hitch back from centre (not compounded). I'm not sure how much of a problem that would cause, but I'm looking into a automatic slider.
Gord

We have seen hitches mounted slightly rearward of the axle in a few trucks and the weights pulled off the front axle was significant, like hundreds of pounds. I explained to them the reason for where the hitch should be and why. Lifting 3 or 4 hundred pounds off that steering axle caused all kinds of issues. Even having it where it belongs could add hundreds of pounds to the front axle if the pin weights were high.

wingnut60
09-19-2009, 06:13 PM
gordonpoole,
Something is wrong with the eng calcs, or they don't have enough info to run the calcs. Assume you move the hitch 10" rearward (180lbs by the eng calculations)--I believe you will find that a 10" movement would be WAY more than 180 lbs off the front. Leverage of the pin weight is probably what the engs don't have to work with.
Joe

gordonpoole
10-01-2009, 11:47 PM
Hi all,
I ran my truck and trailer over the government scales with the hitch centered over my axle and then again with it moved back one notch(4"). The front axle weight difference was 69lb. My trailer weight is aprox. 12000lb and my hitch weight is 2100lb. I then drove aprox 200 miles over a fairly windy and rough road with the hitch back 4" and never noticed any difference in handling.
Gord

BillA
10-02-2009, 11:21 AM
FWIW. Weight on the front axel in a static condition is one point of information. Weight in a dynamic condition is another. You may want to consider that the force on your fifth wheel hitch exerted by your trailer is dynamic (Force = Mass X Acceleration) as the truck/trailer combination moves up and down on their respective suspensions. What this translates to is 2100# pin weight in a static condition will become greater than 2100# in dynamic condition due to acceleration of the trailer in a downward direction and less than 2100# as the truck/trailer accelerates in an upward direction. This in turn will remove more than 69 pounds from the front axle at times and less than 69 pounds at other times. Can't say whether that is an unsafe condition but a margin of steering and braking control is being sacrificed. Also wonder if you may have front tire wear issues down the road.

wingnut60
10-03-2009, 01:20 AM
gordonpoole--
Your weights seem to bear out the engineers calculations--it is surprising to me that there is no more difference than you state, but I should have known better than to argue with engineers.
Change the hitch placement and tow it more to see how it works--no handling problems, then no problem. Go for it.
Joe

kennethwooster
10-08-2009, 11:43 PM
I had the same problems with the F350. After being very careful, a guy that worked for me was moving the rig and took out the back window. I wouldn't worry with trying to place the hitch different. I went with the Super Glide and now I never have to look back. Very smooth hitch.