Do I Have Too Much Torque on My U-Bolts?

[minuteman62-64]

See attached. Note distorted (curved upward) bottom plate and slight reverse curve on leaf spring. U-bolts are 1/2". They are torqued to 80 ft.-lbs.

Trailer/boat combo is 1200 lbs. at most.

The guy at the trailer shop where I bought the springs and hardware told me "..... you can't over-torque these u-bolts." I looked at a UTube video on leaf spring replacement and the guy said torque to 80 ft.-lbs. I just looked on-line and saw a couple of sites that said for 1/2" bolts it would be 65 ft.-lb. of torque.

Questions:

1. Present torque: OK? Too much? I'm guessing not to little.

2. If too much, can I loosen and re-torque?

3. Set torque with wheels on ground or is it OK to do while everything is hanging, as shown in attachment?

 

[j_martin]

Re: Do I Have Too Much Torque on My U-Bolts?

Home made?

You're missing load spreaders, top and bottom. Bottom wouldn't be needed if the plate was thick enough, but it isn't.

U-bolts are overkill for the job.

The springs will fail as is.

hope it helps
John

 

[ufm82]

Re: Do I Have Too Much Torque on My U-Bolts?

Just my opinion but that seems to be upside down. The plate should be on top of the spring and the u-bolts should straddle the axle and come up through the plate with the nuts on the top. That's the way I've always seen them and after 10 years in the construction equipment sales market I've seen lots of trailers. I'd remove the hardware and flip it all. I'd also expect to see a spring pad on the axle.
But, I see the ends of the plate are bowed upwards as well- this isn't from torque- there isn't any torque out on the ends. That plate looks like it was formed to sit on top of the curved spring to me. Your springs are deformed with that double bow in them and will eventually fail in that configuration. I agree with John here.

 

[j_martin]

Re: Do I Have Too Much Torque on My U-Bolts?

Yep. Flip the axle over and put the u-bolts around the axle. The curve in the plate is to compensate for reverse bow that seems to be the rage nowadays for a soft ride.

Yer still missing the load spreader plate for the springs.

 

[rbh]

Re: Do I Have Too Much Torque on My U-Bolts?

YUP, missing parts.
And there is a torque rating for every bolt/nut

 

[beason]

Re: Do I Have Too Much Torque on My U-Bolts?

im with them, it needs to look more like this.

 

[jeeperman]

Re: Do I Have Too Much Torque on My U-Bolts?

You can have the axle ontop of the spring or below the spring.
But in either case you want the bend of the u-bolts going around the axle and the spring sandwiched in between the axle and the u-bolt plate.

Would not the third "load spreader" leaf be included with the spring pack??
The center bolt does not look long enough to ever have had one.

 

[minuteman62-64]

Re: Do I Have Too Much Torque on My U-Bolts?

OK, now I'm totally confused. Here (attached) is the original configuration, straight the Dilly factory. I was assuming the Dilly folks got it right and that was the way it should be, and was attempting to duplicate that original configuration.

There is (or, at least, was) no curve in the bottom plate until I tightened up the u-bolts. It (bottom plate) was flat.

The spring is a two leaf spring, with a 1000 lb. rating. No load spreader was included. What, exactly, is a load spreader? Is that the third, very short leaf that was included in the original spring set?

 

[minuteman62-64]

Re: Do I Have Too Much Torque on My U-Bolts?

I found another Youtube video at http://www.etrailer.com/tv-Install-Leaf-Spring-Trailer.aspx

This looks closer to what you guys are suggesting. Does this guy have it right?

The 5-hole plate/U-bolt combo looks like what I have. I can see where it makes a lot more sense to have the plate on top of the springs.

 

[jeeperman]

Re: Do I Have Too Much Torque on My U-Bolts?

yep like the etrailer video.

 

[LippCJ7]

Re: Do I Have Too Much Torque on My U-Bolts?

Also you have to check for the max torque of the U bolts, if you have exceeded the max then they are done, if not then you can simply reuse them but once a bolt has been over torqued it will fail, do you know what grade they were?

 

[minuteman62-64]

Re: Do I Have Too Much Torque on My U-Bolts?

Also you have to check for the max torque of the U bolts, if you have exceeded the max then they are done, if not then you can simply reuse them but once a bolt has been over torqued it will fail, do you know what grade they were?

Well, I have the grade assessment from the guy at the trailer supply store: "... you can't over-torque these bolts."

I torqued them to 80 ft.-lbs. The on-line references I've since seen show 65 ft.-lbs. torque for 1/2 inch U-bolts, without reference to grade. The way they tightened, most of the torque went into deforming the plate rather than stretching the U-bolts. But, only about $25 for a new set - I'll check w/the trailer shop guys for a more precise description of the grade/allowable torque for the bolts and pop for new ones if any doubt.

 

[CatTwentyTwo]

Re: Do I Have Too Much Torque on My U-Bolts?

I have a small Dilly trailer and the springs are bolted on just like yours are, I guess that's just the way Dilly did it. My U-bolts are 3/8ths with lock nuts and there is no bend in the plate, I would go with lock nuts and a lot less torque.

 

[minuteman62-64]

Re: Do I Have Too Much Torque on My U-Bolts?

I have a small Dilly trailer and the springs are bolted on just like yours are, I guess that's just the way Dilly did it. My U-bolts are 3/8ths with lock nuts and there is no bend in the plate, I would go with lock nuts and a lot less torque.

Yep, that looks exactly like what the old stuff on my trailer was - 3/8 U-bolts w/lock nuts and a thin plate underneath. Looks like my hub and my axle also. My trailer is a 1982 vintage - your's must be very similar.

Once again I'll state how impressed I am with this site. One day and I have all the info I need to move ahead. Thanks, guys.

 

[LippCJ7]

Re: Do I Have Too Much Torque on My U-Bolts?

Once again I'll state how impressed I am with this site. One day and I have all the info I need to move ahead. Thanks, guys.

Actually this isn't a website, its a server at Holiday Inn Express!!

 

[CatTwentyTwo]

Re: Do I Have Too Much Torque on My U-Bolts?

Yep, that looks exactly like what the old stuff on my trailer was - 3/8 U-bolts w/lock nuts and a thin plate underneath. Looks like my hub and my axle also. My trailer is a 1982 vintage - your's must be very similar.

Once again I'll state how impressed I am with this site. One day and I have all the info I need to move ahead. Thanks, guys.

I purchased mine new in 1984. 80 lbs may be fine on the 1/2" U-bolts but it is way overkill for the rest of the hardware and application on our small trailers. I have never checked the U-bolt nuts on my trailer but I would be very surprised if they were much over about 15-20 lbs of torque.

 

[Fishing Dude too]

Re: Do I Have Too Much Torque on My U-Bolts?

This chart might help, u bolts would torque at same values.

http://www.portlandbolt.com/technicalinformation/bolt-torque-chart.html

 

[minuteman62-64]

Re: Do I Have Too Much Torque on My U-Bolts?

Here's where I ended up. Had to get new lock washers - the old ones were mangled in removing the U-bolts (hadn't seen such agressive lock washers before). Turns out the U-bolts were 9/16", not 1/2". Since the plate began "un-springing" as soon as I began loosening the bolts, it looks like almost all of the torque went into bending the plate.

Re-installed the way the guy on the e-trailer video did it. Torqued the U-bolts in an "X" pattern in 10 ft.-lb. increments until the plate was sitting evenly along the top of the springs. Ended up at 30 ft.-lbs. torque on the U-bolts.

 

[Trailerguy34]

Re: Do I Have Too Much Torque on My U-Bolts?

Hello !

Yeah , I too agree with John . It appears you are trying to set your trailer up as "overslung" . Drop those springs below the axle . You want a underslung axle . It rides much better .

Trailerguy

 

[gozierdt]

Re: Do I Have Too Much Torque on My U-Bolts?

I think it's your call for springs over axle vs springs under axle. The springs on my Sea Ray trailer were originally under the axle, but the boat rode very low, and the rear crossmember on the trailer scraped going over dips. I moved them over the axle, and I'm very happy with the result. Rides & tows fine. Outdrive can be lowered all the way without digging a hole. I have to go a little deeper to launch, but not enough to give me any problems. Your setup looks good now with no excessive warping on the plate or the springs. Looked way overtight in the first pic. Go have fun with the boat!!