mike64
Lieutenant Junior Grade
- Joined
- Apr 10, 2008
- Messages
- 1,042
Trying to replace leaf springs on a 1971 trailer (boat and trailer together=1500 lbs), after posting this:
http://forums.iboats.com/showthread.php?t=389370
So I removed a leaf spring and the hardware... and two trailer parts stores later, I can't believe how frikkin hard it is to find the right hardware. I picked up new leaf springs, but the u-bolts are a size nobody has (3/8" diameter, 1-5/16" wide, 3-1/4" long). So I'll have to custom-order u-bolts, which will probably be ridiculously expensive. I figure I'll reuse the bolt plate, which is a nice thick piece of steel. Here's what they look like:
So question 1: which of these options should I pick for my custom u-bolts?
Finish: zinc chromate, yellow zinc dichromate, hot dipped, bare metal, Xylan coating
Material: Grade 2, Grade ASTM B-7, S/S304, S/S316
Threading: Roll, Cut, UNC, UNF, Left Hand, Right Hand
Question 2: the old leaf spring had a round knob on top that fit into the hole in the center of the bolt plate. The new one has a nut on top that is too big to fit in the bolt plate hole. The bolt through the new leaf spring is not long enough to go through and tighten the nut. Should I just remove the nut, or do I need to get a longer bolt that I can tighten a nut on over the bolt plate? Here's a pic of the old and new leaf springs:
Question 3: The guy at the store said my old shackle bolts were the wrong kind, I needed shackle bolts that were a bigger diameter to fit in the spring eye properly. But the new shackle bolts won't fit in the holes on the trailer frame. Can I get away with bolts of the old diameter, or do I need to enlarge the bolt holes on the trailer frame? Here's a shot of the old and new bolt hardware:
Finally, how serious do I need to be about torquing the bolts? Do I need a torque wrench, or just cross-tighten evenly and good and tight?
http://forums.iboats.com/showthread.php?t=389370
So I removed a leaf spring and the hardware... and two trailer parts stores later, I can't believe how frikkin hard it is to find the right hardware. I picked up new leaf springs, but the u-bolts are a size nobody has (3/8" diameter, 1-5/16" wide, 3-1/4" long). So I'll have to custom-order u-bolts, which will probably be ridiculously expensive. I figure I'll reuse the bolt plate, which is a nice thick piece of steel. Here's what they look like:

So question 1: which of these options should I pick for my custom u-bolts?
Finish: zinc chromate, yellow zinc dichromate, hot dipped, bare metal, Xylan coating
Material: Grade 2, Grade ASTM B-7, S/S304, S/S316
Threading: Roll, Cut, UNC, UNF, Left Hand, Right Hand
Question 2: the old leaf spring had a round knob on top that fit into the hole in the center of the bolt plate. The new one has a nut on top that is too big to fit in the bolt plate hole. The bolt through the new leaf spring is not long enough to go through and tighten the nut. Should I just remove the nut, or do I need to get a longer bolt that I can tighten a nut on over the bolt plate? Here's a pic of the old and new leaf springs:

Question 3: The guy at the store said my old shackle bolts were the wrong kind, I needed shackle bolts that were a bigger diameter to fit in the spring eye properly. But the new shackle bolts won't fit in the holes on the trailer frame. Can I get away with bolts of the old diameter, or do I need to enlarge the bolt holes on the trailer frame? Here's a shot of the old and new bolt hardware:

Finally, how serious do I need to be about torquing the bolts? Do I need a torque wrench, or just cross-tighten evenly and good and tight?