Lots of u-bolt info in the search but not specific enough. On the 84-85 axle, the factory truss makes the bottom of the housing square. Some folks run a 3.25" u-bolt vs. a 3" because the 3" sits funny on the axle.

My question is this: I am having custom u-bolts made for my u-bolt flip. If I had two square bottom u-bolts made for the long side of the axle, should they be 3" or 3.25" wide?

Am I overlooking something simple?

I just run round bottom Rancho u-bolts on mine, 5/8"x3.25"x8.75" (p/n RS17436) and they work fine. Cut to length as needed, grind a small notch where they go around the corners of the truss. I've seen too many of the square bolts break at the sharp bend and I find the round ones work perfectly fine. I like the Rancho bolts because they seem to last a long time, I have 5-6 years on my fronts, no signs of stretching or stripping out. The larger diameter probably helps in that regard, they only get torqued to 30-40% of their rated load.

I just used some longer, regular round "help" ubolts from AutoZone and beat them into place. Was a PITA, but works.

wow, I've never heard of u-bolts breaking, square or round bottom. Once again, Roger comes through with info.

So my next questions are this:

1. If you notch the truss on the long side, why would you even need 3.25" instead of 3"? It seems like it would work with 3" and the grinding/notching.

2. If I get the 3.25" for the long side, should I get 3.25" or 3" for the short side?

I stripped the threads on a set of 1/2" round u-bolts that came w/ my AllPro u-bolt flip kit, and I also saw one of those 1/2" round bolts break on Scott Wilson's old 4Runner SAS. Since running the 5/8" bolts, they have held up fine, I think I run 3.25" in all 4 locations up front, 3" may fit on the long side, but it was easier to get all 4 the same, I'll be running 3" on the rear axle.

U-bolt flip kit info

I gently placed my All-Pro ubolts in the parts bucket and replaced them with NAPA 5/8" ubolts. Some quality time with the press, opening up the bend oh so slightly, then bending back the forward leg, gave my passenger side front the perfect fit. Almost fell into place. No change in torque values now due to stretch, or stripping either.

Bill, you always crack me up! <img src="/forums/images/graemlins/lol.gif" alt="" />

Anyhow, as an update, I went to get them bent(1 hour drive to nearest city, Fresno), and although they were only $7, they were out of the threaded end stock to make them and wouldn't have any for at least two weeks <img src="/forums/images/graemlins/shocked.gif" alt="" />. Well, I went to thier competitor, and he would happily make them for me, at a cost of $16 each <img src="/forums/images/graemlins/shocked.gif" alt="" />(without washers or nuts)

I said no thanks, and went to 4WPW with my tail between my legs and ordered the Rancho units Roger suggested, and uses, for $12.99 each w/ nuts and washers. They charged me $3 to ship them to me as I live in the sticks.

The first u-bolt flip will be for the Chevy rears and the second, for the SAS. I will have pics in the next several weeks of my progress.

Get semi-round u-bolts if you can, they fit much better on a long truss axle.