U bolt nut torque

[richfaa]

I was a bit confused about the torque on the U bolt so I called Dexter and spoke to Glen who is the rep who is always at the Fall rally'

The 7 K axle uses a 1/2 U bolt and the nut size is 3/4.That is what confused me. Glen said The torque should be between 45 and 70 preferably toward the higher end .I mentioned I thought he said 60/65 at the rally and he said that was a good number.

NOW this is what I do NOT remember him saying..THE TORQUE READING SHOULD BE WITH THE WEIGHT OFF THE AXLE.WE SHOULD JACK THE RV OFF THE GROUND BY THE FRAME FOR THE READING TO BE ACCURATE. I did not have that note in my book from the seminar.

[DQDick]

You're correct. Two years ago we had the discussion with them on the U bolts not being tight enough from the factory and last year we had a more conventional discussion. Taking the weight off the axles was never discussed.

[Art-n-Marge]

Holy cow, I've never heard of that.

This would imply to me that with the weight off the axle, reaching 65 ft lbs (what I've been used for u-bolt torque on my 6,000 lb axles) would be achieved a lot quicker than if the weight of the rig were on the axle. This means I am torquing too much if I do this when the axle is holding the rig's weight.

Now what?! Do I loosen the u-bolts (since they are probably too tight), then raise the rig at the frame and retorque. Does this mean I have to get all new u-bolts and nuts, since if I've overtorqued, I've possible stretched the u-bolt too much. I'm remembering that once u-bolts are loosened or removed they should be replaced since they are compromised.

Fortunately I don't use my rig near as much as many of you, but what have I done to myself and what's the recovery? While 4 sets of U-bolts and proper nuts aren't all that expensive it's still funds I'd prefer to use for say, a trip to the yogurt shop with the grandbabies.

Any ideas, folks?

[jlb27537]

Hello Guy's, been doing this for 30+ years. I have never checked the torque of the u-bolts. Something else to worry about/not.

Jim

[Irlpguy]

quote:

Richfaa wrote:

NOW this is what I do NOT remember him saying..THE TORQUE READING SHOULD BE WITH THE WEIGHT OFF THE AXLE.WE SHOULD JACK THE RV OFF THE GROUND BY THE FRAME FOR THE READING TO BE ACCURATE. I did not have that note in my book from the seminar.

This person cannot be serious, the springs sit on top of the axles, it would be impossible for there to be more weight on the U bolts when sitting in a normal position than when lifting on the frame.
The U bolts hold the springs in place on the axle, they are not load bearing in any way.

I think this fellow was on a paid vacation from the accounting department, and has no idea what he is talking about.

Most if not all U bolts on our units will be 1/2 x 20, torque them to 60# and don't add some other nonsensical equation to confuse anyone here.

What next, you have to lift the wheel off the ground to get a true reading of the air pressure in your tire.

[bethandkevin]

Great posts jlb and Ed!

[richfaa]

I would suggest that you call Dexter ask for Glenn as ask him the question. Glenn has been with Dexter for many years and is at the Fall rally every year. Now I know nothing about the subject. I asked the question and that is the answer I got. I will call again tomorrow and ask the same question and ask him to explain.

[simonsrf]

Anyone own a frame jack?

[bigmurf]

Poor Glenn.

[WeBeFulltime]

Yep, Glenn is in for a BUSY week!

[simonsrf]

quote:Originally posted by bigmurf

Poor Glenn.

I wonder if we would all get the same information if we each called Glenn?

[bigmurf]

Poor poor Glenn. Does he drink, he will have a reason now.

[pineranch]

This forum is the reason I checked the bolts. All were less than 20 ft lb. I was pi--ed and called dexter and asked to whom should I holler at. This very nice rep explained that it was all on dexter. They ship the complete assy to keystone. She apologized and I Q'ed the bolts to 65 ft lbs and they haven't budged since. Soooo, jlb, your unit is new and if you haven't touched those bolts, how do you know you didn't get a Friday afternoon "close enough" job.
Mike

[dsprik]

Rich, wasn't your U bolt slippage the problem on your way to the Great Lakes Rally at Mackinaw City a few years ago? I recall you lost all four tires from the Montana going down I-75 at an angle. You had to stop at Burnside RV/Camping World in Houghton Lake to get new tires and have your axles re-alighned and the U bolts torqued properly?

Maybe I was thinking of a different problem?

[dieselguy]

I think perhaps everyone should take a deep breath here and let up on the panic button. Why the unloaded axle recommendation ... I haven't clue, but tomorrow will bring an answer. We here on the MOC are way more informed on maintenance than the common RVer, so we have more to worry over Fact is there are thousands and thousands of Rvers out there that haven't a clue what a u-bolt is and in their entire ownership it hasn't mattered. Most of us own a $10 Harbor Freight torque wrench to carry along in the RV with us ... they don't repeat the best and are approx. 5% accurate. They are better than guessing. We all don't have the same amount of rust on the U-bolts and under the nuts when we check the torque. I'm going to continue to yearly check them as I always have ... tires sitting on the ground. That approach has not failed me in over 20 years. If Glen has a good story to back up his recommendation ... so be it. This is not something to make us all park our rigs till he answers.

[Irlpguy]

I want to say with certainty, if every axle that left the Dexter factory were properly torqued we would never have to worry about them, they should not loosen up over the course of a years driving, it just should not be something we should have to worry about. In all the years I have owned trailers from flat deck tandems, to single axle old travel trailers I have never once been concerned with or ever checked the U bolts, nor have I ever had an issue because of them.

What we have learned here on the MOC forums however, is that there are cases on our Montana's where the U bolts have required tightening and obviously were not properly torqued from the factory, so most certainly check them and torque them to the recommended ft lbs.

I am awaiting warranty replacement axles complete with hubs & brakes to replace both those on my Montana dream home, I assure you the axles will be checked for sufficient grease and the U bolts will have their torque checked.

Rich do not take all this personally, you are only the messenger, so we won't shoot you. I assure you though I won't be calling Glen.

Jeez dieselguy I paid $189.00 for my torque wrench and I get one free calibration if I suspect it is incorrect....

[dieselguy]

Ed ... you're always good for a chuckle! I have more expensive torque wrenches in my shop as well. What I was getting at is many of us just carry a HF wrench as they are way cheaper when you don't need a super precision tool and what we think we are torqueing could be off by several lb/ft. As for calibration, I was told by a local instrument shop that HF torque wrenches have no means of re-calibration once assembled in China. Soooooooooo that's the rest of my story.

[Irlpguy]

You sure know how to take the wind out of a guys sails dieselguy, I was so looking forward to something for free, oh well I am sure if I don't use it as a pry bar it will outlast my Montana.

[pineranch]

Worked with various Q wrenches in my 30 year AF career on aircraft. Q wrenches are checked against a standard. We sometimes mistake checked for calibrated. If one checked bad, it was discarded. If torqueing head bolts I would want a nuts on wrench, u- bolts, no so much, say +/- 5 ft lbs OK. JMHO
Mike

[richfaa]

You are correct Dave My U bolts worked loose on our 06 3400 and I had never checked them for torque.

Like I said. I asked the question of Dexter from a person who should know the answer and that is the answer I got. There are many here who know Glenn from the rallies and he is not from accounting. I will be asking "why" to day. Till then what he said stands with me.