Questions about leaf spring hardware

[mike64]

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?

 

[JB]

Re: Questions about leaf spring hardware

Try www.championtrailers.com, Mike.

They always had what I needed and gave me great advice on installing.

 

[Titanium48]

Re: Questions about leaf spring hardware

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

Stainless is overkill if this is a freshwater only application, but I'd probably go with something stronger than grade 2. Get left hand threads if you want to irritate and thoroughly confuse whoever touches the axle next.

Question 2: [/B]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:

Don't mess with the spring center bolt, just drill out the bolt plate so it fits around the nut like it's supposed to.

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:

I'd drill out the holes on the trailer and use the new bolts. The old ones probably need replacing anyways and the springs might wobble a bit from side to side if the bolts are too small.

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?

If you have one, you might as well use it. If not, it's a trailer axle, it doesn't have to be exact. To estimate torque without a torque wrench, divide the torque specification (in ft-lbs) by the length of your wrench (in feet, from the center of the nut to the center of your hand) and try to apply that much force.

 

[dozerII]

Re: Questions about leaf spring hardware

From the photo of the springs it looks like the new spring has the center bolt intalled for and under slung and axle and the old ones for over slung. Just put aclamp in the new spring set close to the center remove the center bolt and put it in the opposite way. The round end will fit in youe ubolt plate.

 

[mike64]

Re: Questions about leaf spring hardware

Thanks JB, I'll give them a call tomorrow.

Thanks Titanium48! Good info.

From the photo of the springs it looks like the new spring has the center bolt intalled for and under slung and axle and the old ones for over slung. Just put aclamp in the new spring set close to the center remove the center bolt and put it in the opposite way. The round end will fit in youe ubolt plate.

Good thought dozerII, but the axle goes on underneath the spring, and has its own hole for the bolt part sticking out of the spring, which is also too small for the nut. The old spring had a round "button" end on both sides of the center bolt. I might as well drill out the bolt plate.

Hey, what am I going to need to know and to have equipment-wise to enlarge the bolts holes on the trailer and steel plate? Can I use a regular drill and just get a carbide drill tip?

 

[Stachi]

Re: Questions about leaf spring hardware

have a second plate made for each side and use regular bolts....no u bolts...

 

[cedarjunki]

Re: Questions about leaf spring hardware

just drill out the plate to fit.
drill or replace hangers on trailer for correct size.

the spring/trailer shop near me custom bends all there u-bolts.... maybe call around and see if anyone close to you does it....

 

[mike64]

Re: Questions about leaf spring hardware

Thanks everybody. Stachi, that was a good idea, but I found a place that makes custom u-bolts and they're selling me 4 for like $18. Now I just have to get a carbide bit and borrow a heavy-duty drill to make the bolt holes bigger and I'll be good to go.

 

[Lion hunter]

Re: Questions about leaf spring hardware

All the hardware for the springs should not be hardened. Carbide bits are nice but not a necessity. Springs on the other hand can kill a bit in seconds.

 

[cedarjunki]

Re: Questions about leaf spring hardware

Carbide bits are nice but not a necessity.

especially since your basically reaming out the holes instead of drilling fresh holes. doing this by hand you may actually break a bit or two. carbide would get expensive.
bits are designed to cut along the whole edge but when you try drilling the next size or 2 larger then the edge of the cutting bit catches and possibly snaps or if your using a powerfull 1/2" drill you might be spun around a few times if you have a good enough grip.