I have FJ62 springs in the back of my FJ40. There is a recipe of bushings and hanger pins that will let this work, providing you re-locate the rear hanger. Do a search-I posted the bushing part #s and The OME pins in another post.
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2bad-I just test fit the FJ62 springs on the back of my 71 40 yesterday. Worked great by the way. Just curious if you changed out the frame spring hanger? I thought you would have to, but with the right bushings and pins it all works. I did change the shackle hanger for one of those heavy duty Ruffstuff ones.
For the rest-if you want to run FJ60 springs in the FJ40 original spring hangers (the fixed end at the frame) you need SOR bushing 289-40-X. It has the proper outer diameter of 1 3/8 inch, a narrow flange and a 15mm hole. Then you use OME pins which are 15mm. This is the only combination I could come up with that would work. Otherwise you have to replace the hanger with a wider one.
The basic problem is that FJ60 springs are 3 1/4 wide with standard bushings. Fj40 springs are 3 inches wide with standard bushings. The springs themselves are the same width. So the hard part is finding narrow flange bushings, with the right outer diameter and the inner pin size appropriate for something you can buy.
Curious what others have done. BTW I looked at Isotel's solution, which is more work, but I may go to this in time.
Sorry about the moderate hijack.
edit--One other thing-FJ62 springs have an extra leaf, and may be even more desirable than FJ60 springs. I got a very clean set from Mudrak-and added a #2 leaf from my old FJ60 pack after cutting off the military wrap. Used new Rockford pins (Napa) which are exactly the same head diameter as stock rear FJ60, which is a large head if you remember.
Here is a pic of the rear shackle hanger. The pin moved back 3-4 inches over stock, and the whole axle moved back about 5 inches. You will need to extend your driveshaft of course.
There is also a pic of the front spring hanger with the 62 springs in place and the new longer driveshaft..
Drew's post outlines what I recall my friend Mike had to do when installing 60 Series rear spring packs under his '78 FJ40. Biggest hassle for him was re-positioning the rear shackle hanger - be sure to measure four times and weld once!
Here is a pic of the rear shackle hanger. The pin moved back 3-4 inches over stock, and the whole axle moved back about 5 inches. You will need to extend your driveshaft of course.
There is also a pic of the front spring hanger with the 62 springs in place and the new longer driveshaft..
Hmmm...I like the idea of moving the rear axle back without making too much of a fuss...been daydreaming of making an BJ44 copy one day, and this info is good to know.
