lengthening frame

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Jan 18, 2003
Mountain Hole, Idaho
Has anyone here accomplished this feat?
Doing the tear down of my project FJ40 I discovered some serious rust in the panel that runs behind seats. The body looked good until I removed the factory tool box, the rear panel was completely rusted out including the body mount area. It seems water had found a way in the channel and caused all kinds of damage. Anyways in order for me to fix this I had to separate the body from behind the door posts and drill out the spot welds running along the bottom seam. Once apart, the rust was worse than I thought, but still repairable.
Looking at the body pieces, I began to visualize converting the front body into a cab, sort of resembing a FJ45 P/U. To do this would probably cost the came as fixing the rear part of the tub.
Looking at where the visualized FJ40/45 hybrid tub would sit, I noticed it would be more benifical to lenghten the frame. By doing this I could easily have room to fab a flat bed for the back, improve rear driveshaft length, and have room for a doubler. What do you think, wild idea or what......
my buddy runs a FJ45 pickup on a stretched FJ40 frame. Very doable, but a fair amount of work to ensure the frame remains square and true.
check out Jack Rice's FJ45 project under the Tech Links or go here


He acutaly Shortened the frame instead of lengthened it BUT in order to get the LWB FJ45 it looks like toyota added about a 7 inch section to the frame (that he actualy cuts like 5 inches out of?????)

Anyway sounds like a Kick Ass project...keep us posted if you do actualy do it and take lots of pictures!!

Woody, do you happen to know hom much your buddy extended his frame?
Thanks for the link cruzer, that has a lot of good info on it!
How about a fj 40 converted into this..



I do not have a detailed write up opn this sort of a project.. I plan to have one ready by a month or so..
Incredible! :eek:
Thats a little too long for what I was going to do Eshan...Your mechanics do some fantastic work...I'm always impressed!:skull:
mmmm, pity we are separated by an ocean, as I had to cut 13" out of my 45 to make a FJ4x. I call it the 4x as it has actually 101" wheelbase. If we were closer we could have just swapped frames! We don't get the 40 here, but plenty of 45's.
mmmm, pity we are separated by an ocean, as I had to cut 13" out of my 45 to make a FJ4x.  I call it the 4x as it has actually 101" wheelbase.  If we were closer we could have just swapped frames!  We don't get the 40 here, but plenty of 45's.
Well.. This is longer then a 45.. We do have 45s here but extending those is as costly, if not more then extending the 40 as 45s are more expensive then 40s..
Boy that sure would be rough having to many 45's running around. ::) :D Thats a problem I wish I had to live with. Although I really would be disapointed if I didnt have my 40.
I still have the 10" sections that I took out of the FJ45 LWB frame referenced above by Cruzer. Let me know, Ranger, if you want them. If I were lengthening a frame, I would follow Toyota's lead and include a sleeve to strengthen the frame.
Thanks for the offer Medusa. I actually have an old 40 frame that had the front tweaked in an accident. I am going to use the middle portion of the frame for splicing material. I will definately have sleeves made to go over the spliced area. Just have to find a place to bend the metal. From what I can tell from the pictures of this sleeve, it appears to just cover the outer portion of the frame and overlap the top and bottom, correct?
It also seems that Toyota welded the inside of the frame and not the outside, I imagine this was done so the sleeve would fit flush to the outside of the frame.
Medusa, do you happen to know the thickness of the sleeves that Toyata used on the frames? I would imagine it would be the same thinckness as the frame. Also what did you do about the inner part of the frame, did you remove all of the rivets, take it out, cut and reweld, and reinstall? I have been pondering how to tackle this.
Thanks for the help!
If you look at my pic above, although I shortened the chassis, the principle is the same. I had 1/6" steel bent to form each side of the sleeve. (like u-channel) The frame was first cleaned, bevelled and then welded. Then I ground the frame welding flush and placed the 2 sleeve-halves over the chassis and welded them to the chassis. Believe me, the original fram will break before the join.
Look at the pic above, you will see the sleeves are not square ended, and the 2 sleeves do not align exactly on each side, this is to distribute the stress across more surface area.

One thing I had to deal with when shortening a 45 frame was the frame taper. I had to use a hydraulic puller to pull the frame together in order to meet the cut-off section. I don't know if the reverse will apply if you lengthen the frame.
FJAfrica pretty much answered the questions you asked of me. 3/16" steel is a close match to the LC frame. I welded the outside joints and then ground them flush so the sleeve would fit over them. On the inside frame rail, I removed a section and welded in an insert. Also, as FJAfrica points out, make all you cuts and welds diagonally across the frame. Have fun :D
FJAfrica, can you post some more pics of your FJ4x? Pics that show the whole rig from the sides? I wanna see what it looks like... What did you do for a top? Custom softtop? Modified hardtop? No top? If you have a website, send me there, if you want to email them to me you can as well. I would appreciate it.
OK, here are a few pics, somehow I can upload pics here, but not to my profile? ???
I cut 13" out the middle of the chassis, as well as everything behind the rear shackles.
As we don't get the 40 over here, most of the parts are custom made.
The rear body section I made out of 1/8" steel, (nice & strong). The rear bumper is out of 1/4" steel. The tubing is 2.1/4" (2.5mm wall thickness). The front panels are fibreglass. Custom shackles and 35" BFG's.

Although I have not updated the site in a while, you can see the construction of the rear body here. http://www10.brinkster.com/4x4/
If u want more pics or info email me on offroad@ananzi.co.za

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