Leaf Spring Center Bolt (1 Viewer)

[amos715]

i have read several threads and can not find the size.

fj-55 leaf spring center bolt.

 

[jtoro]

3/8 ?

 

[amos715]

yeah that's probably close, but i was looking for the metric size.

i am going by and picking up a handful of bolts i need, and i wanted to get the u bolts and center bolts before i take apart the springs to add leaves

 

[Degnol]

Well, if you are going to add leafs, you'll probably need a longer bolt anyway. I think I used 5/16 when I used '40 springs for a trailer project. 5/16 was slightly larger than the stock hole in the spring but not much larger.

GL

 

[fj40forlife]

40 spring pin bolts are smaller

 

[6740inCo]

3/8 was what I came up with on my swap done on my 67

 

[amos715]

ok thanks guys

 

[bsevans]

I use 3/8" SS socket head fine thread bolts with Nylok SS nuts. When I rebuilt my spring packs I converted to this bolt size. I ran a cobalt 3/8" drill through each individual leaf to make sure there was clearance. The socket head is just the right size to align the assembled spring pack with the axle.

 

[pb4ugo]

I use 3/8" SS socket head fine thread bolts with Nylok SS nuts. When I rebuilt my spring packs I converted to this bolt size. I ran a cobalt 3/8" drill through each individual leaf to make sure there was clearance. The socket head is just the right size to align the assembled spring pack with the axle.

I use 3/8" socket head cap screws too. My after market springs had 3/8" center pins. You need to know how thick the springs are when they are compressed, so you get the right length bolt. Most black SHCS are made of alloy steel and are stronger than Grade 8' HHCS.

EDIT: you also need to upgrade the nuts. If you use grade 8 bolts then at a minimum you would need grade 5 nuts. Internal threads are stronger than external.