Trailer Axle U-bolts

dlsmith

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hmm.. if the axle is below the springs, ubolts don't support the weight. That configuration is the most common. I think that's called 'overslung'. Underslung , where axle is below the springs, drops the trailer bed down about 3" more or less but then ubolts do support the weight.
I think you meant when the axle is above the springs.
 

North Idaho Wolfman

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As for the 'strength', the bolts only 'bind' or 'mate' the axle to springs ,no real 'strength' is needed, if axle is above springs, most trailer are this way.
This what you originally wrote, my comment was regarding when you said the axle is above the spring.

The U Bolts on an over the spring axle must be very strong, in fact most are greatly overrated.

An under the spring mount axle does not require as much strength, but it is critical to have good quality strong U-bolts, especially for curb / bump / junk in the road.
 

GeoHorn

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That link says not to reuse the ubolts as the threads are roll formed, not cut.

OK.... has anyone bought ANY bolts that were CUT, if so where and $$.

The 'don't reuse if rollformed' would also apply to every bolt I've ever come across in the past 50-60 years....

Hate to think what a machinest turning a lathe would charge for a 'cut' bolt....
Well...that’s bass-ackwards. (I only saw where they state not to re-use U-bolts and did not see any statement about cut vs rolled threads, but what you posted is backwards.)

Rolled threads are more durable than cut threads because cut threads create “stress risers” which can lead to cracks. That is why Aircraft bolts are ROLLED threads...never cut threads.
 

i7win7

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Most semi-trailers now use air ride suspensions, however we have a local spring repair shop that bends their own u-bolts. A 1" fine thread with 1 1/4" thick nuts are kind of impressive. Last resort if you need something stout.
 

BigG

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I guess that is what I am trying to figure out. Do I replace and upgrade the 1/2" u-bolts or does this transfer the damage to another area? Or do I just go through the trailer and replace all the hardware every year or so? The u-bolts, the spring hanger bolts, the equalizer bolts and the springs?

I do not over load this trailer as I do not want the DOT watching me. I have in the past been pulled over by the same DOT officer 3 times.He is always looking to write me up. He gave me an OOS (out of service ticket) because the breakaway cable was hooked onto the hook of the breakaway chain. I changed it as he told me how he wanted it hooked up and he still gave me a ticket.

Anyway I digress. My GMC 3500 has over 430,000 miles with only the front left wheel bearing replaced as far as the undercarriage goes.

I guess I will change it all. Thanks to all for your help.

My other trailer was a Moritz out of Ohio with torsion axles and I did not have these problems. Those were Dexter axles and they ate the bearings.
 

Magicman

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"I changed it as he told me how he wanted it hooked up and he still gave me a ticket."

Apparently he was one ticket away from writing his quota for the day. :rolleyes:
 

BigG

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The officer was upset because he told me that I needed to have a CDL. My truck and trailer weight rating less then 26,001 lbs so there is no need for the CDL. This ticked him off and he spent over 1/2 an hour until he found the brake cable. I had been through several inspections without any problems before this guy.

It was an OOS ticket which means you must correct the deficiency before you can drive the truck. What he did not tell me is the person who makes the repair (me) must sign the ticket and fax the ticket to Tallahassee. At the bottom of the ticket in very small print it says something to the effect that failing to have the repairs made and faxing in the ticket would result in a fine of thousands of dollars per day until the paperwork is sent in.

So he was not able to ticket me for a moving violation, He stood there and watched me hook the brake away cable to the D-ring with a carabiner and he even told me I was now OK but he wrote the OOS anyway.

He wanted me to pay the penalty for not sending in the paper work I am sure.
 

GeoHorn

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I am ordinarily a “rules-follower” type of guy.

But in SW Austin, Tx there is a city-within-a-city “Sunset Valley”. They have police officers who take themselves very seriously as Gestapo and much like the citation-issuer mentioned above. Cough without covering your mouth gets you a fine.

The other night I was in Sunset Valley purchasing my grandson a fishing rod/reel at Academy for last weekend’s fishing outing on the lake. Afterwards I ate at Luby’s cafeteria and the sun had set and a huge crowd of drivers were in the streets like it was Xmas shopping-days (probably hoarding trips... I had a difficult time checking-out at Academy for all the gun/ammo purchasers standing in-line.)

I made a wrong turn and ended up at a traffic light with a “no U-turn” sign dangling beneath it, but as the four-way intersection was dark and everyone still had red traffic lights for a moment, I took advantage and made a U-turn.... and was IMMEDIATELY followed by a Sunset Valley police car with lights a-flashing!

I pulled into the next parking lot and rolled all my truck windows down so the officer could approach and see into my truck cab clearly as he approached, keeping my hands on the steering wheel.

He introduced himself, and told me I was stopped because I’d made an illegal U-turn UNDER a red traffic light...and RIGHT IN FRONT of him! .... and wanted to know where I was going and my driver’s license. I informed him I was wearing a handgun and gave him my license and told him I’d just shopped for a fishing rod and lived out west on a ranch. (I used to live in Austin and I was fully aware I was about to receive absolutely NO favors from a Sunset Valley police officer.)

He went back to his car for a few minutes... then returned to my truck and politely informed me he was issuing a “verbal warning only” and informed me that the entire mile of Broadie Lane I was traveling did not allow U-turns. (I already knew that as I used to live nearby.)... but, I couldn’t believe what I was hearing.

I might buy some lottery tickets. I’m definitely contributing to the next Sunset Valley Police Officer’s Assoc’n charity event!

Cops are people too.