U bolts on axles

[CygnusSailor]

I checked the tightness of the U bolts on my axles. Most were tight, but the passenger side rear was noticeably loose. I probably added about 3/4 of a turn to all four nuts. The nuts on mine were 7/8". It's best if you have a deep well socket. As others have said, it's a good idea to check yours. Maybe a 10 minute job and could save a lot of grief.

[geondebi]

I check mine once a year and before leaving on a long trip. I also check the bolts on the hitch mounting. I always find one that needs a little turn.

[salda01]

After having one axle separation whenthe unit had less than 1,000 miles on it and then replacing an axle last year, I check mine every couple of months. I still don't understand why out of all the people we camp with no one has had loose bolts like I have had.


Edited by: salda01

[delqcc]

You might want to think about pulling the nuts off the next time you check and placing the strongest threadlock you can on them.

Never have thought to check mine. So, I just did and had two bolts that were a little loose; about 3/4 turn to tighten them. Thanks Deputydog

[fixit5561]

I put new springs and u bolts on last year in the spring. I also checked them last year after about 200miles, andin the middle of summer because of stretching, (they will stretch when new I was told).

I checked mine the beginning of this year, and will do so every year now because they may stretch a bit. I check them with a torque wrench set at 65lbs. thats about what the norm is for my TT in my sig below.



They do seem to have to be tightened just a little so far every time I have checked them. Maybe something to keep and eye on.

[ClassicHammond]

Is 65# the recommended torque?

[fixit5561]

Yes that is what an internet search had found me, 65# was about the norm. Some suggestions were more and some less. This was from instruction manuals online. I think it was axle manuals for the most part.

[drcook]

Lowes, hardware stores etc sell nuts with a piece of nylon in them that will keep the nut from loosening up. I am not sure on the price for them at this size though on whether it would be cost effective. Regardless of whether you would purchase locking nuts or plain ones, a good practice is double nutting. Tighten the first one down, then turn the next one down and using an open end (or crescent, don't use a box end or you won't be able to get it off most likely) to hold the first, torque the new one against the first. You won't have to use your gorilla arm, just a good torque. This will keep the two of them locked together and from loosening. The only way to get any type of looseness is for the U-bolt to stretch or metal to compress on the perch/axle.



Now that you all have brought this to my attention (Thank You!), I intend to check mine and double nut them.



dcEdited by: drcook

[Hamops]

Originally Posted by drcook

Lowes, hardware stores etc sell nuts with a piece of nylon in them that will keep the nut from loosening up. I am not sure on the price for them at this size though on whether it would be cost effective. Regardless of whether you would purchase locking nuts or plain ones, a good practice is double nutting. Tighten the first one down, then turn the next one down and using an open end (or crescent, don't use a box end or you won't be able to get it off most likely) to hold the first, torque the new one against the first. You won't have to use your gorilla arm, just a good torque. This will keep the two of them locked together and from loosening. The only way to get any type of looseness is for the U-bolt to stretch or metal to compress on the perch/axle.



Now that you all have brought this to my attention (Thank You!), I intend to check mine and double nut them.



dc

Be sure that before you buy the "aircraft" nuts that they are a Grade 8 nut. When I had an axle replaced last year, the repair shop said that the U-bolts were Grade 8 standard.

[drcook]

Sorry, I wasn't a 100% clear, and you have an excellent point, but I was saying that regardless of whether you use a nylock nut or a regular nut, use either one as a jam nut, in which case it doesn't matter if it is grade 8. Jamming the 2 together simply keeps them from moving and a nylock nut is just extra insurance and may really be redundant and an unnecessary expense.



Now I am curious as to thesteel grade of the U-bolts themselves. Iam going to have to look into it.

[r2millers]

You will find that the locknuts DC is referring to at Lowes will not be grade 8. Most of their basic stock is grade 3 with some grade 5 on SAE (fine threaded) stock. The grade 8 bolts will have 6 notches on the head with the number stamped on the nut. I don't think you will find grade 8 locknuts. Probably will need to use lockwashers with regular high grade nuts instead.

[cwit]

I may be wroung but I would think u-bolts are of a mild metal because they are bent cold and dry threaded.

[r2millers]

Cwit,

You are correct, the u-bolts aren't grade 8. I really doesn't make sense to use grade 8 nuts on a mild steel u-bolt. The important thing is to use proper lock washers and check regularly to ensure they are torqued to spec.