Sheared pin on Leaf Spring

[Smoky]

I have a 1961 Avion T-27 dual axle trailer. To make a long story short I managed to shear off the center bolt/pin on one of my leaf springs. I have a six leaf spring and it looks like it sheared off right above the bottom leaf...so the bolt/pin is still going through the top five leaves but the axle shifted back about one inch causing abnormal tire wear. I need to travel from New Mexico to Wisconsin in a few weeks and need advice on how to repair this. The leaf springs are fine....can I just loosen the Ubolts and replace the old pin or should I install a new leaf spring?

Thanks for any tips.

p.s. I say bolt/pin because I haven't taken it apart yet and I'm not sure how it works. Is it a bolt that screws into the axle, or is it a little nub that the axle sits on?

[barts]

If you've managed (somehow) to shear or rust off the center pin, you'll need to get a new one the right length, raise & support the trailer on jack stands & remove the wheels on both sides of the the affected axle and loosen the other side u-bolts so you have some slop. You can then get a jack under the axle, loosen the ubolts on the broken side and drop the axle sufficient to permit replacement of the pin. While you're there, check to make sure the hole in the axle mounting pad/plate hasn't been opened up excessively.

Reassemble w/ new lockwashers & nuts. A bit of Loc-Tite on the threads wouldn't hurt either.

Lots of images on how this works if you image search on google for leaf spring center pin.

- Bart

[Smoky]

Originally Posted by barts

If you've managed (somehow) to shear or rust off the center pin, you'll need to get a new one the right length, raise & support the trailer on jack stands & remove the wheels on both sides of the the affected axle and loosen the other side u-bolts so you have some slop. You can then get a jack under the axle, loosen the ubolts on the broken side and drop the axle sufficient to permit replacement of the pin. While you're there, check to make sure the hole in the axle mounting pad/plate hasn't been opened up excessively.

Reassemble w/ new lockwashers & nuts. A bit of Loc-Tite on the threads wouldn't hurt either.

Lots of images on how this works if you image search on google for leaf spring center pin.

- Bart

Thanks Bart. Any idea what size center pins are on these old leaf springs? I found some here.
Leaf Spring Center Bolts, Leaf Spring Center Pins Suspension Parts - AutoandTruckSprings.Com

Perhaps its one of these bolts at etrailer?

etrailer.com - Products Accessories and Parts Leaf Spring Center Bolt

Also, How much should I torque the nuts on the ubolts?


Thanks for the advice.

[barts]

I have no idea what size those may be... a bit of disassembly is required .

THese guys seem to have some opinions... and some torque values. They don't like lockwashers; given the torque values they recommend, I can see why.

U-Bolts - Eaton Detroit Spring

I'd definitely inspect that spring; if the ubolts loosened it may be broken as well.

- Bart

[Smoky]

Great. Thanks for that link. I will definately check my springs for cracks. I hope I can fix this problem with some new u bolts and a center bolt. I'm thinking of just cutting off the old u bolts with an angle grinder.

[putback]

Some additional ctr bolt info. most common dia. is 3/8, occasionally 5/16, allways fine thread, common at auto parts stores. Buy one longer than you need so you can use it to compress your spring stack, cut the excess bolt, leave 1/8th ish tail to peen and "lock" the nut, never use a lock washer. You never reuse a ctr bolt, they are stretched. Make sure round bolt head is in receiver hole on X, NOT the nut end. U bolts are also stretched after 1 use. Consider new ones. Most common reason for a repeat ctr bolt break is rust, dirt ect, left between the spring leaves. You tighten the stack, the leaves flex and grind the crud to powder resulting in a loose spring stack that moves and shears the new ctr bolt. Its allways easier to just cut the U-bolts, but be aware of the possibility of things under tension flying. Sometimes fatally!

[Smoky]

Thanks for the advice. Repair went smooth and solved my problem. Made the trip from Arizona to Wisconsin with no problems. $19 for new U bolts and center bolt.