Hi--I've got a '67 FJ45 long bed with a frame that is toast. I've got a late 60's FJ40 frame that I have hanging around and was wondering if anyone has lengthened a 40 frame to fit? I thought I heard that they were almost the same?
Has anyone ever altered a 40 frame to fit 45 long bed?
- Thread starter kpfoten
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Yes you can do it,the rear frame is the same,you need to lengthen the rear put the 45 springs in the 40 frame to get the rear axle centerline. I will post up pics of the frame I had started.
The 45 spring mounts are solid so you should move them,the three bottom rivets are the same but the side ones are different location. The 45 uses the springs to locate the axle rearward and the axle will end up more in the center of the frame arch. The bump stop will need to be moved. Also the tubular crossmember in front of the rear springs will need to rotate up. The 40 and 45 spring hangers have the same (970mm) 38 3/16 centerline. The 45 rear shock mount crossmember is wider than the 40,So you will have to change it.
I cut my 40 frame donor off in front of the front body frame mounts around 63 inches from the rear axle center line and the calculated the from the front to arrive at 116+ inches.
I used 2x4 angle iron to keep the two frames alined one on the side and one underneath the frame with 4 clamps on each piece. I also used a piece of mig welding wire to pull a straight line down the frame and under the tail to get the proper height to the rear leaf spring centerline,so in short the top of the center part of the frame should line up with the center of the rear spring hanger eye.One of the charts for a 45 has the dims for the centerline of the rear spring hanger is a Australian 45 but I would think they are the same.The austrailianframe chart has alot more details than any other on I have seen.
The 45 spring mounts are solid so you should move them,the three bottom rivets are the same but the side ones are different location. The 45 uses the springs to locate the axle rearward and the axle will end up more in the center of the frame arch. The bump stop will need to be moved. Also the tubular crossmember in front of the rear springs will need to rotate up. The 40 and 45 spring hangers have the same (970mm) 38 3/16 centerline. The 45 rear shock mount crossmember is wider than the 40,So you will have to change it.
I cut my 40 frame donor off in front of the front body frame mounts around 63 inches from the rear axle center line and the calculated the from the front to arrive at 116+ inches.
I used 2x4 angle iron to keep the two frames alined one on the side and one underneath the frame with 4 clamps on each piece. I also used a piece of mig welding wire to pull a straight line down the frame and under the tail to get the proper height to the rear leaf spring centerline,so in short the top of the center part of the frame should line up with the center of the rear spring hanger eye.One of the charts for a 45 has the dims for the centerline of the rear spring hanger is a Australian 45 but I would think they are the same.The austrailianframe chart has alot more details than any other on I have seen.
Last edited:
- Thread starter
- #3
Thanks!
- Joined
- May 21, 2009
- Threads
- 296
- Messages
- 1,382
- Location
- Paradise Calgary Alberta Canada
- Website
- forum.ih8mud.com
If you look at the frame diagram in the book and compare you will see where the differences are. From there you will see where to add material from your local steel fab. shop that can bend you the mat'l.
Now that your thinking of doing that you may also want to consider adding a suspension correction kit in the front and galvanizing the frame.
Check for a solid frame by hitting it real hard with a ball pene hammer, from there you may choose to add stiffener plates.
If you mig weld it use a gas bottle and not flux wire.
Cheers
A.M.
I have done it... search my build.
Medusa's rig was my inspiration.
Medusa's rig was my inspiration.
