1 – Ton Shackles

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The raw material once again provided by the guys at Tri-Angle Metal Fab. When the rear pinion bearing in the front diff seized and stopped the 109 hard, it wound up the right front suspension (pretty much like the abuse most people put their old Series trucks through off road) and caused the front drive shaft to contact the relocated oil pan breather pipe. I have plenty of clearance, but under extreme circumstances, the two may meet again. So, after a conversation with Mark and Arthur at RN we decided that extending the shackles would get the “extreme event” clearance I need, I wouldn’t have to re-work the oil pan (again), and it will pitch the Salisbury back a bit (more oil to the back bearings, thank you very much). And for the tech-heads out there, yes, the caster angle will change, but only a few degrees, and in the tighter, not sloppier steering direction. So off to the Bridgeport………..

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The blanks and the stock shackles

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Start drilling…..the magnetic indicator holder allows you to place each identical blank in the same place every time……….this saves a ton of time in set up and edge finding, you only have to do your set up once this way

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Another gigantic time saver, and a guarantee of accuracy……the digital readout (DRO).

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The math to plug into the DRO…….assured perfection

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Another nice trick on the Bridgeport……drill the holes, then put the spindle in neutral, insert the tap, rotate by hand, the hole gets tapped perfectly straight

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Best stuff on earth for tapping…….like butta

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Drilled and tapped, fronts and rears

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Spacers for the front shackles were cut from solid bar, bored on the Bridgeport, then tig welded to the shackles

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Cleaned up and ready for coating

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Coated with POR15……..rock hard finish, goes on quickly and self levels, and when you get it on your hands it stays there for weeks!

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Mounted up with center support

7 Replies to “1 – Ton Shackles”

  1. so you didnt put any wedges in the front or the back to correct pinion angle or castor angle ? always thought about putting military shackles on my 88 but was advised not to . ive had a set sitting here for a few years now collecting dust . maybe i will put them in.

  2. I can imagine! but very impressive anyway.

    I avoided stating the obvious of ‘why not simply buy some military shackles?’ but I guessed that was not so simple for you in the States. They are pretty common here and cost a few pound a set. I think yours looks slightly longer but not sure. Many of the military ones I’ve seen have ties welded between each pair, I guess to reduce too much flexing?

    I know they give big lifts as many people fit them to gain clearance for larger tyres. Not sure why to be honest as my wifes truck run 33″ tyres without any clearance issues anyway and that is probably as big as you’d want to go on a series.

    My concern is that the front prop angles would cause vibration. Not a problem if you have FHW’s but you don’t. I’d appreciate knowing how you get on with them as I’m running the same engine as you in my Series 2 and while that does have Rocky Mountain paras, I’m intending to do a fair bit of off roading so will be testing the axle articulation and don’t want the prop or diff hitting the sump or crank pulley. I am tempted with the idea of extended shackles for mine to avoid this so I’d appreciate knowing if they cause any issues. Thanks.

  3. Hi Troy,
    See my response to Ian below, he asked pretty much the same question……….kind of a lengthy response to type twice.
    Thanks,
    Colby

  4. Hi Ian,
    I did have 1-ton, or military shackles on the truck…….at least what’s available stateside that they call military shackles. The shackles I’ve machined are 1.5″ longer than what I had. I did build a support to create an “H” for added rigidity (I’ve added a photo to the post of the finished shackle mounted to the frame). I didn’t weld it in, just copied what I used to see in old Chevy and Ford heavy pickups back in the day. The support is a 1/2″ grade 9 shouldered bolt inside a 3/4″ tube (1/8″ wall thickness), should give plenty of support under stress.

    I think because I’m dealing with a front Salisbury I’m in a unique situation as far as prop shaft vibration/angle and caster concerns. The 1.5″ shackle changes my caster on the truck just about -4 degrees, but here is the catch, the Salisbury diff when in the truck is angled up toward the transfer case (for whatever reason, it’s just the way it sits on the leaf springs, the front prop shaft has essentially a straight line from output to transfer), which from what I’ve read, is normal for these axles/diffs. So it’s possible that I’ve been dealing with “light” or “vague” steering all along, and the -4 degrees may make the truck drive even better (kind of tough with the power steering, everything feels too easy). In the end, I’ll have no prop shaft issues because the diff will now sit close to level like the normal Series diff with the usual universal angles, and I think my caster will actually be right where it’s supposed to be, and if not, the caster is at least angled toward the “non-centering, stiffer” steering side.

    I’ll drop you a note and let you know what I think of the drivability once everything is back together.
    Thanks again,
    Colby

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