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Front traction bar build

Opiebennett

Red Skull Member
CAL4
Joined
Aug 19, 2020
Member Number
2750
Messages
143
Loc
Port Orchard, WA
Took on some side work on a Toyota for a friend. The previous owner of his truck has a slip and twist - round bar inside a pipe style traction bar on the front end to control pinion wrap. After clanking down the trail a bit, my buddy couldn't stand the noise, so unbolted it.

Anyway, he asked me to build something quieter.

Lots of thoughts about instant center and anti- dive came to mind, and the ever present concern of a shackle inverting and really messing things up.

Some measuring, some arts and crafts, and this donkey mount that fits on his reinforced transmission cross member was born. Uses a creeper joint as the pivot.
 

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Opiebennett

Red Skull Member
CAL4
Joined
Aug 19, 2020
Member Number
2750
Messages
143
Loc
Port Orchard, WA
Because the moment arm created was so big, I was concerned about ripping the trans cross member to pieces. I welded 3/8 nuts to the inside of the arm on one side, and built a support from 2x2x.120 that welded to the drivers side frame rail, and bolts to the upper mount, so the trans cross member can still be unbolted.

Some shackles the same length as the leaf spring shackles, to keep the arcs all moving together (I hope) made from 3/16 with a 1/8" overlay.
 

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Opiebennett

Red Skull Member
CAL4
Joined
Aug 19, 2020
Member Number
2750
Messages
143
Loc
Port Orchard, WA
Assembled the upper creeper joint, Welded the upper mount in the car, temp assembled the lower joint and shackles, set shackle angle the same as the leaf springs, cut and fit some 1.75x.120 DOM...

Welded some extra reinforcement on the bushing ends of the bar so the .120 wall tube containing the bushing doesn't peel open. Test fit, welded in.
 

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Opiebennett

Red Skull Member
CAL4
Joined
Aug 19, 2020
Member Number
2750
Messages
143
Loc
Port Orchard, WA
Paint, assemble, 18mm bolts everywhere. Final angle within one degree.

He's taking it out this coming weekend, and will report back.

Overall shot of the rig.
 

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Aisin

Grumpy old fuck
Joined
May 19, 2020
Member Number
304
Messages
1,598
Nice work. I remember many moons ago Dr Smash did a write up on the other site.
 

YotaAtieToo

Thick skull
Joined
May 19, 2020
Member Number
142
Messages
5,489
Loc
Bonners Ferry, ID
Fwiw, you don't need a long shackle on the traction bar. It's not a leaf, so it's not getting shorter and longer through travel.

Also, it looks like you did a good job making the frame mount beefy. The axle side is the one you have to pay attention to. Although, being in the front, it should never see as much stress as the rear.

Looks good though, should help with having the leaf shackles on the wrong side :flipoff2:
 

Opiebennett

Red Skull Member
CAL4
Joined
Aug 19, 2020
Member Number
2750
Messages
143
Loc
Port Orchard, WA
Fwiw, you don't need a long shackle on the traction bar. It's not a leaf, so it's not getting shorter and longer through travel.

Also, it looks like you did a good job making the frame mount beefy. The axle side is the one you have to pay attention to. Although, being in the front, it should never see as much stress as the rear.

Looks good though, should help with having the leaf shackles on the wrong side :flipoff2:

I figured the leaf springs we’re getting longer and shorter with travel, and therefore the axle was moving back and forth, so by making the shackles the same length ~5.1” as the leaf springs move the axle, which moves this bar, it should be moving together.

Definitely agree on the axle mount - the previous bar had some large 1/4” plates with lots of material there that I left in place - but I did reinforce the bushing holders on the bar it’s self so they wouldn’t peel open.

Of course the proof is in the pudding, so we’ll see how it goes this weekend!
 

YotaAtieToo

Thick skull
Joined
May 19, 2020
Member Number
142
Messages
5,489
Loc
Bonners Ferry, ID
I figured the leaf springs we’re getting longer and shorter with travel, and therefore the axle was moving back and forth, so by making the shackles the same length ~5.1” as the leaf springs move the axle, which moves this bar, it should be moving together.

They just aren't really going to move together since one is rigid and one is a spring. My point is that the traction bar shackle only has to do with fore and aft motion and not the elongating leaf. So it shouldn't have to be as long.

However, a typical rear traction bar is on the fixed side of the leaf, so it wouldn't have to deal with much fore and aft movement. This is on the same side as the shackle, so it's going to see more movement. What you did is definitely the safe move. I'd be curious to see pics of it flexed up and down.

I'd also think about putting a stop somewhere around 45* forward to keep it from getting stuck in line or inverting when he's on a break over climb and the axle is trying to walk forward.

Definitely agree on the axle mount - the previous bar had some large 1/4” plates with lots of material there that I left in place - but I did reinforce the bushing holders on the bar it’s self so they wouldn’t peel open.

Of course the proof is in the pudding, so we’ll see how it goes this weekend!

I ripped/twisted an IFS rear right at the big web from a traction bar mount, and that was in a stripped Sami :laughing:
 

ToyodaAddict1980

Well-known member
Joined
Mar 22, 2021
Member Number
3706
Messages
46
I ripped/twisted an IFS rear right at the big web from a traction bar mount, and that was in a stripped Sami :laughing:
I've seen alot of posts like this over the years, pretty much talked me out of trying a rear anti wrap bar.


When you guys set these up, do you still set the pinion 2* under, or do you assume the anti wrap bar will stop all pinion movement and set it at 0*? (assuming CV shaft)
 

Opiebennett

Red Skull Member
CAL4
Joined
Aug 19, 2020
Member Number
2750
Messages
143
Loc
Port Orchard, WA
I've seen alot of posts like this over the years, pretty much talked me out of trying a rear anti wrap bar.


When you guys set these up, do you still set the pinion 2* under, or do you assume the anti wrap bar will stop all pinion movement and set it at 0*? (assuming CV shaft)
This one had a non-CV single u joint at each end shaft, and I didn’t play with pinion angle - and this is a full hydro trailer rig that likely doesn’t see much more than 40mph ever, so wasn’t as much a concern.

I’d have to treat it like a 3 or 4 link suspension and assume very little movement with a bar - so right on the ideal u-joint angles for what you are trying to achieve.
 

Provience

Kill!
Joined
Jul 8, 2009
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15
Messages
8,101
Loc
Thurston County, WA
The shackle and axle swing is why I think "right" would be the ladder bar on the fixed side of the spring, and the fixed side as the long side, which would mean going to a front shackle on the springs. Without doing all that and the frame work involved, a longer shackle, such as this, on the free side of the spring makes the next most sense.

Digging it :smokin:
 

Opiebennett

Red Skull Member
CAL4
Joined
Aug 19, 2020
Member Number
2750
Messages
143
Loc
Port Orchard, WA
From the owner-

"it worked real good. Washed her up and was going to take a good look at it later. so far its awesome. extremely happy with it."


And the one photo I stole from Facebook
 

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