quick D70HD u bolt measurement needed

[SkysTheLimit]

Can anyone measure a stock D70HD u bolt for me real quick? I want to make sure i get the right part from napa or Stengel Bros. Need bolt diameter, length & inner bend diameter.

Thanks!

 

[thatK30guy]

Should be a square bend, no less than 2.5" inside width and the rod thickness is 5/8".
Length will vary. Depends on if the truck ran the helper/overload spring on top of the pack.

The tubing diameter of these rears are 4". The square bend u-bolts are factory and have the threads pointing downward as the main u-bolt plate is on the bottom of the axle.

 

[SkysTheLimit]

I didn't realize they were the downwards pointing ones. I have to move my perches anyway, can I just have DIY4x fab me up some perches and have the u bolts point up with the round bends?

the axle came out of a 90 crew cab dually if that matters.

thx

 

[thatK30guy]

Yes, round bends can be fabbed easily. DIY is an excellent choice to use as I've had Kert make some stuff for me before.

The bend will still be 4" i.d. The length is up to you. Measure the perch height, leaf pack thickness and add 4" for the tubing diameter and approximately 2" for the exposed threads above the u-bolt plates and you should be fine with that.

John (nvrenuf) should be chiming in sometime. I think he went to a thicker u-bolt than stock. Stock is 5/8" thick rod and I think he went to something like 3/4". Lets see if he responds.....

 

[SkysTheLimit]

Many thanks. I'll see what John has to say and then give Kert a ring.

 

[nvrenuf]

Yep, I bought 3/4" for mine... they just seem more proportionate to the axle housing. Mine are the round, upward style - 3/4" thread dia x 4" tube dia x 10" long. My length was to fit the axle with stock perches, 2.5" thick springs and 1/2" thick plates.

I bought my plates from Blue Torch Fab for about $45 + freight. Nice thick stuff with the ends bent 45* like OE plates.

 

[SkysTheLimit]

Where'd you get your bolts from if you don't mind?

thx

 

[nvrenuf]

Local spring shop that bends to order, they cost me about $140 but they are grade 8 with moulded threads.

I bought a same size set prior to these that had cut threads, I had a buddy with a shop that cut me a deal - $60. Inspite of the fact they were 3/4" dia I still stripped one with a short handle ratchet BY HAND W?O a cheater bar. I now have that u-bolt hanging on the wall as a reminder of a PITA lesson learned.