Leaf spring center bolt size?

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I'm taking apart some rear leafs on a 70 FJ40 this weekend to install some angled shims can someone tell me the center bolt size so I can have some ready to install? TIA
 
i use cap screws the are available at most hardware stores .
 
I had the same problem on my fronts. I added shims to make up for longer shackles and the bolt heads don't go into the axle mount so the axle can slide. I ended up using a set of grade 8 bolts upside down with double nuts on the top. It made it long enough to capture the axle, but I don't like it.

Do they make the bolts with taller heads for this purpose? I am getting ready for a spring flip in front so now's the time to do it right.
 
I had the same problem on my fronts. I added shims to make up for longer shackles and the bolt heads don't go into the axle mount so the axle can slide. I ended up using a set of grade 8 bolts upside down with double nuts on the top. It made it long enough to capture the axle, but I don't like it.

Do they make the bolts with taller heads for this purpose? I am getting ready for a spring flip in front so now's the time to do it right.

Yes, I just got a set to replace a broken one. They are long to to go through the shim into the perch.
 
Not sure what you use your rig for, but....

While you have it all apart.. drill all the center holes in each leaf bigger and run a larger diameter bolt thru them.. A lot of people say a masonary bit works well.. I used a carbide ball end-mill to make the holes 7/16..
my 2 cents
 
The center pin size varies by year. Early 40s are quite small, FJ60s are significantly bigger. I've made it a habit to drill them out to 7/16 and use either a grade 12 cap screw, or a Rockford spring pin that size from Napa. The head is then 5/8 inch and you may need to slightly drill out the hole in the perch.
 
Not a bad idea. I already bent a grade 5 5/16" bolt in a front spring pack. I upgraded to grade 8, but larger makes sense. I am going to redrill for a spring flip anyway. Might as well go larger.

The center pin size varies by year. Early 40s are quite small, FJ60s are significantly bigger. I've made it a habit to drill them out to 7/16 and use either a grade 12 cap screw, or a Rockford spring pin that size from Napa. The head is then 5/8 inch and you may need to slightly drill out the hole in the perch.
 
Hi All:

I have used a Uni-Bit to both enlarge existing pin holes and drill new ones in spring leafs. The trick is to use a slow-speed drill (like, ~ 250 RPM) and lots of cutting oil.

Regards,

Alan

Not sure what you use your rig for, but....

While you have it all apart.. drill all the center holes in each leaf bigger and run a larger diameter bolt thru them.. A lot of people say a masonary bit works well.. I used a carbide ball end-mill to make the holes 7/16..
my 2 cents
 
i use cap screws the are available at most hardware stores .


x2, mine has a hex screw. I had to open up the bottom plate a little.
 
They ended up big just a little smaller than the 3/8" ones I bought, just had to drill the holes out a little bit. I'm working on a spring over that was not done very well. I've added a 4 degree shim and installed a rear drive line with CV style upper joint and still have some vibration right at 45 mph. The FJ40 also has a GM 5.3L/700R swap so the rear drive line is super short. My local guy had a problem sourcing parts to build a rear drive line with the CV style joint and I'm wondering if it's still part of the problem, anybody know a good drive line builder for Toyota drive shafts??
 

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