rear axle u-bolts

[LCAM-01XA]

So I'm needing new U-bolts for the Sterling in my 1-ton, and I get a hold of big spring shop I found highly recommended online, they say my truck calls for bolts with 3-5/8" tube diameter. I go measure my axle and it's 3-1/2" tube diameter. Spring shop swears their u-bolts will work fine, as that's all they install on Fords with big axles. We're talking 5/8" grade-8 bolts here that get torqued to 170lb-ft and then provide clamping force of over 16,000 lbs. So maybe I'm being paranoid, and the 3-5/8" bolts will work fine on the 3-1/2" axle.... What says the collective?

 

[gatorman21218]

Dunno I had a hell of a time finding U-bolts to fit my front axle. I ended up taking the old ones to a spring shop and they bent some for me. I also upgraded from 9/16 to 5/8. Where are you located?

I dont think an 1/8 is going to matter once those things are torqued down. My guess is it will form to the shape of the axle tube.

 

[LCAM-01XA]

Did you make the fronts 5/8"? Factory ones are 3-1/16" wide by 8" long, 9/16" shaft. This for D60. Stengel Bros has them in stock and ready to ship, and they fit good. Minor beveling is needed at the edges of the top plates because the bends of the new bolts are not as tight as those of the factory bolts, but that's hardly a big deal. I have a pair of D50 bottom plates I'll be using, passenger side gets the full plate (cause the D60 welded-on one is downright pathetic and bends easily as you torque the bolts), driver side gets just the front part of the plate (cut right behind the front set of u-bolt holes) cause of the cast iron bracket. I'm using these plates mostly for increasing my options for a swaybar, my D60 came with no bar and I'd like to have one so I'm probably gonna run the 2wd F350 bar with the modified D50 bottom plates.

Idk if the rear bolts will conform to the axle tube, kinda doubt they will, the material is quiet strong. But maybe it's elastic enough that it does so upon initial install, or it's stiff enough to never do it at all. My only real concern is the bolts will conform to the axle tube dia as I put mileage on them. Which following Murphy's law will inevitably happen during a long road trip

 

[gatorman21218]

Yes I did make them 5/8. I drilled out the plates to receive the new size.

yeah I dont know what the answer is

 

[Iowa 73]

3-5/8", 5/8" is what you need. That is what I just put on my '97 and they fit perfect.

 

[Dieselcrawler]

Since you mentioned Stengel, and I know you are sorta in my area since you came to the one rally, I would also look up auto truck spring. They are out of harleysville. That's who I deal with anymore. Little cheaper then Stengel, and made to order if you call them

 

[Agnem]

I usually just take an old one, or the backing plate to Bud's Spring service in Lancaster, and they make me new ones while I wait.

 

[LCAM-01XA]

3-5/8", 5/8" is what you need. That is what I just put on my '97 and they fit perfect.

Were they a bit loose around the axle at first? Do they snug up and conform to it as you tighten them down?

Since you mentioned Stengel, and I know you are sorta in my area since you came to the one rally, I would also look up auto truck spring. They are out of harleysville. That's who I deal with anymore. Little cheaper then Stengel, and made to order if you call them

Haha, actually normally I'm clear across the country from you, almost in towcat and icanfixall territory! I just happened to be in the area picking up a tractor for a buddy down south (got it so cheap it was almost a steal), that's why I couldn't stay too long, somehow I doubt all your truck activities would have worked out good for me while dragging a Ford 8N tractor in tow. Anyways, I'm kinda committed to Stengel now seeing how I have their bolts in my hand, I just wanted to know if they sent me the right bolts - I ordered for a brick dually and 14" long (extra length for thicker leaf packs), they sent the 3-5/8 bend ones, so I'm just making sure I'm good to go before I install them and void any possible return.

I usually just take an old one, or the backing plate to Bud's Spring service in Lancaster, and they make me new ones while I wait.

I can't quite do that yet, I need my axle to stay how it is so I can decided how much I wanna lift it to match the front + an inch or two. Since I was making the order for the fronts anyways I just estimated and got the rears at the same time to save on shipping. But these do in fact match the backing plates well... Go figure.

 

[towcat]

if you're in my neck of the woods, "Betts spring co." will bend stock to your spec or your sample while you wait.
they're all over kali.

 

[Iowa 73]

Were they a bit loose around the axle at first? Do they snug up and conform to it as you tighten them down?

They fit just just right around the axle tubes, and they are centered in the spring plate holes.

 

[LCAM-01XA]

Guess I really should have asked where to get those made before I jumped the gun and got them... I bet those will fit a D70U perfect tho, with its 3-5/8" tubes. Iowa73, idk what your definition of just right is, but these definitely seem loose around the tubes - I can pull them up snug so the tube is at the bottom of their bend, and I see daylight between the tube and the sides of the bolts. Not much obviously, but the gap is there. As opposed to my current ones that fit snug all around (and IIRC were a bear to install but once the tube slid past the threads it was a glove fit. Looking at another truck that still runs its factory bolts they also fit snug w/o any gaps on the sides...

So what do ya'll think I should do? Take their word for it and install these things and be done with it? Or return them (they are off-the-shelf items, not custom jobbies) and get new ones made to actual 3-1/2" bend?

 

[Iowa 73]

idk what your definition of just right is, but these definitely seem loose around the tubes - I can pull them up snug so the tube is at the bottom of their bend, and I see daylight between the tube and the sides of the bolts

Mine have no daylight. '97 sterling. Parts list says 3-5/8, though I never did actually measure them. These are included in the rough country lift kit.