Pirate 4x4 banner
1 - 12 of 12 Posts

·
Registered
Joined
·
1,328 Posts
Discussion Starter · #1 · (Edited)
lengthening gooseneck trailer,best spot to cut and lengthen?

I have a 24 foot gooseneck with dovetail. I need to add 5 feet to it so that I can carry both of my vehicles. Both vehicles combined come in at 10000 pounds.
I am interested in hearing suggestions on where is the best "spot" on the trailer to cut it and lengthen it. The rails are 10 inch I beam that is .250 thick. I am using two pieces of 6 foot matching I beam and doing the "step cut" instead of butt welding back together.
The two spots I have looked at is about 18 inches from where the "gooseneck" is attached to the trailer. or two feet in front of the "front" trailer axle. Thoughts and suggestions. Thanks
 

·
Vendor
Joined
·
1,009 Posts
I'm curious about other's thoughts on this too, we have a 18 ft GN that needs to be 25 to put my cabover on it. If someone finds good tech somewhere else please link it here!
 

·
Registered
Joined
·
98 Posts
This is the way I did the trailer above, I really didn't want to mess with cutting the neck off and lengthening it and I didn't want to lengthen the rear and have to move the axles and fenders etc...So I cut in front of the axles and added 4'.





Fish plating




I took 1/4" angle and plated the inside/bottom of the entire extension






It may not be the best way or the "right" way, but it's the way I did it and so far so good. It's been to TTC last year weighing in @ over 10k and it's been on 10 other wheeling trips of between 100-200 miles. Tows great and haven't noticed any faults to it yet, just make sure the joint has nice fish plating and I added the extra support under the entire extension to make me feel better.
 

·
Registered
Joined
·
1,328 Posts
Discussion Starter · #6 · (Edited)
thanks for posting the pictures. That is basically one of the way I was envisioning doing it. Only exception is my trailer is I beam and I was planning more of the cut being "z" cut on both ends of the splice. I have found the following link,http://www.pirate4x4.com/forum/tow-rigs-trailers/612992-stretching-trailer.html which discuss the appropriate ditribution split and there is apparently a formula to figure it out. Did you notice any changes to how the trailer tracked or anything? Obviously turns will be a little different since the axles are further back.
 

·
Registered
Joined
·
2,798 Posts
There are no vehicle inspections in oregon. You can pretty much do any changes you want. The only time the DMV will inspect is when bringing in a vehicle or trailer from out of state and then registering it in oregon and even then they only do a vin inspection. (knocks on wood) Hopefully they don't start the safety inspection thing I hear about on the east coast.
 

·
Registered
Joined
·
98 Posts
When I was reading up on cutting the frame I did alot of searching on how people extend semi truck frames, I don't know if the "Z" cut is the best because it leaves alot of 90 degree corners that might be a stress point and might crack in the future. Also when you fish plate it make sure the ends of the plate are rounded.
 

·
Registered
Joined
·
80 Posts
My ol man shortened the frame on a 90' 10lug super duty that was loooong. He done the "z" cut but he rounded the corners (instead of squaring them) to make a seem less continuous weld and put a single fish plate on the inside and it has held no problem for bout 15 years 500,000 mi with a cummins and weighing 16,000 pounds as a service truck with an Autocrane service truck bed. Just sayin :)
 
1 - 12 of 12 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top