Question: Traction bar mounting location?

[frankenstien]

You need some flex built into it. This is from off-road design but you could make it yourself

yes! this is the type i am putting on my 74 with a 6'' lift. they make a kit to use that is everything minus the DOM. they use a johnny joint up front and a shackle

i might swap the bushing end for a johnny joint and have the heim joint at the other and see how it does. I am going to weld tabs to the axle tube this time(I think) have to find some tabs

 

[Chevy1925]

Personally, I see a u-bolt issue and not an axle wrap bar issue.

What are using for bushings? How many times have you reused those u bolts and what are you tightening them to?

If you use a single triangulated axle wrap bar, you better weld the housing to the axle tube. Two would spread the load out without the need for welding unless you go sled pulling

I’ve ran axle wrap bars like yours that i built for my self and friends about 7 years ago. I tow very heavy (2200lbs pin weight with a 15k toy hauler on the back and no air bags) and have 4” blocks. Never had this issue no anyone I know running the bars I built but I also replace u-bolts every time they come off.

 

[frankenstien]

Personally, I see a u-bolt issue and not an axle wrap bar issue.

What are using for bushings? How many times have you reused those u bolts and what are you tightening them to?

If you use a single triangulated axle wrap bar, you better weld the housing to the axle tube. Two would spread the load out without the need for welding unless you go sled pulling

I’ve ran axle wrap bars like yours that i built for my self and friends about 7 years ago. I tow very heavy (2200lbs pin weight with a 15k toy hauler on the back and no air bags) and have 4” blocks. Never had this issue no anyone I know running the bars I built but I also replace u-bolts every time they come off.

The U bolts were brand new when I installed the bars, I had to cut the old ones off. I had my Local shop bend them up for me, iirc they are 5/8'' rod. I also replace them when they come off, i have always been told thats what you do with them.


I am using 2 5/8'' wide 2'' diameter bushings at the frame and heim joints at the axle with spacers to allow for more movement, i believe they are 7/8'' shank and 7/8'' hole iirc. I got an extra set of the axle cups that the u bolts go through on the axle and welded a flat plate on them and some ears for the heim.

I do not intend on using a triangulated arm on my LLY, I am thinking about using the same type tabs in N2BRK's thread (https://thorbros.com/4-link-parts/4-link-mounting-tabs/4-link-axle-tab) like that. welding them to the bottom of the tube to take the stress off the U bolts.

the heaviest thing i have carried with them on is my 400 gal water tank approx 3400lbs in the bed with air bags, and tow a camper thats approx 5klbs. the truck i was towing home when it broke, was maybe 5k? ish

 

[Chevy1925]

The U bolts were brand new when I installed the bars, I had to cut the old ones off. I had my Local shop bend them up for me, iirc they are 5/8'' rod. I also replace them when they come off, i have always been told thats what you do with them.


I am using 2 5/8'' wide 2'' diameter bushings at the frame and heim joints at the axle with spacers to allow for more movement, i believe they are 7/8'' shank and 7/8'' hole iirc. I got an extra set of the axle cups that the u bolts go through on the axle and welded a flat plate on them and some ears for the heim.

I do not intend on using a triangulated arm on my LLY, I am thinking about using the same type tabs in N2BRK's thread (https://thorbros.com/4-link-parts/4-link-mounting-tabs/4-link-axle-tab) like that. welding them to the bottom of the tube to take the stress off the U bolts.

the heaviest thing i have carried with them on is my 400 gal water tank approx 3400lbs in the bed with air bags, and tow a camper thats approx 5klbs. the truck i was towing home when it broke, was maybe 5k? ish

well that explains why they broke. notice how they broke right at the bend? that is the weak point when you bend steel. Then you put the rod under high tension at the stretched point and snaps. what ever steel they use is junk to be bent and then torqued to what ever torque you sucked them down to (need to know where you are torquing these to still or if you are just hammering them down with an impact). i wouldnt use those again though.

what kind of bushing though, IE: poly, delrin, rubber, etc.

changing the bushing at the frame while having heims on the axle side wont stop anything. you are not out articulating the heim joint by any means as im sure you have high misalignment spacers on them as well.

in my opinion, this a u-bolt/torque issue hands down. not the axle wrap bars. yes the bars dont help as they cause pinion angle change through the suspension travel (makes the axle move in an arc instead of straight up and down or close to it like the spring will move) but the change you are seeing is nothing like the change i had when i ran a deaver mini pack and loaded the truck down with my toy hauler when i first bought it. i have no bump stops and with the 5th wheel on the truck, my leaf pack was in a 3-4" negative arch (extremely bad on leafs not designed for that) and had an S look to them from the bars. i actually hauled the trailer quite a few times that way till i got air bags on, then ditched the mini pack and bags to put the overloads back in and run the truck as is. If the bolts are breaking from pinion change, i dont see how they are going to hold the axle when you load the truck, hit the throttle and get axle wrap when you run no bars. that could get scary fast.

 

[OregonDMAX]

I would never mount the back end of the bar to the spring pad you're just asking for problems I welded my traction bar mount on the axle side directly to the axle tube.

 

[frankenstien]

well that explains why they broke. notice how they broke right at the bend? that is the weak point when you bend steel. Then you put the rod under high tension at the stretched point and snaps. what ever steel they use is junk to be bent and then torqued to what ever torque you sucked them down to (need to know where you are torquing these to still or if you are just hammering them down with an impact). i wouldnt use those again though.

what kind of bushing though, IE: poly, delrin, rubber, etc.

changing the bushing at the frame while having heims on the axle side wont stop anything. you are not out articulating the heim joint by any means as im sure you have high misalignment spacers on them as well.

in my opinion, this a u-bolt/torque issue hands down. not the axle wrap bars. yes the bars dont help as they cause pinion angle change through the suspension travel (makes the axle move in an arc instead of straight up and down or close to it like the spring will move) but the change you are seeing is nothing like the change i had when i ran a deaver mini pack and loaded the truck down with my toy hauler when i first bought it. i have no bump stops and with the 5th wheel on the truck, my leaf pack was in a 3-4" negative arch (extremely bad on leafs not designed for that) and had an S look to them from the bars. i actually hauled the trailer quite a few times that way till i got air bags on, then ditched the mini pack and bags to put the overloads back in and run the truck as is. If the bolts are breaking from pinion change, i dont see how they are going to hold the axle when you load the truck, hit the throttle and get axle wrap when you run no bars. that could get scary fast.

I am guilty of not torquing the U bolts, i snug them with the impact equally, then use my 18'' handle ratchet to tighten them down evenly, I will say they are F@#$ing tight, i get them locally, they are the only place local to me that makes them to length, i needed a little longer for the add a leaf, i have used them many times for my 74 and never had any break.

I am using a poly bushing. yes i have misalignment spacers on the heim

 

[frankenstien]

I would never mount the back end of the bar to the spring pad you're just asking for problems I welded my traction bar mount on the axle side directly to the axle tube.

thats what im thinking just weld some tabs on the axle tube

 

[zakkb787]

Your 74 doesn’t put down ANYWHERE NEAR the amount of torque your duramax does. Any time you bend something it creates a weak point.

 

[frankenstien]

Your 74 doesn’t put down ANYWHERE NEAR the amount of torque your duramax does. Any time you bend something it creates a weak point.

Yes! I forgot to state that my Dmax puts down way more. But I did use it for about 2 years straight to haul my water tank. And the 74 wheel hops like no other

 

[frankenstien]

Got my bracketa to weld on my rear axle tube, do you guys just disconnect the batteries when welding on your truck? Or do you just go to town? I just dont want to damage any electronics

 

[OregonDMAX]

Doesn't hurt to disconnect the power and ground and isolate them.

 

[Bdsankey]

Got my bracketa to weld on my rear axle tube, do you guys just disconnect the batteries when welding on your truck? Or do you just go to town? I just dont want to damage any electronics

When I welded mine on I just went to town with everything hooked up. Your rear axle is isolated via rubber bushings in the leaf springs to the rest of the truck as well as rubber brake line.

Best practice? No, but thing still ran just fine.

On customers vehicles I disconnect the batteries and even go as far as ECM/TCM but then again they aren't mine.

 

[frankenstien]

thats what i was thinking, just disconnect the batteries and i should be ok, i have seen lots of threads on guys who build bumpers etc on the truck with out disconnecting stuff

 

[frankenstien]

got them welded on last night, just disconnected the batteries, no real issues, learned how not good i am at welding upside down, with the new tabs they are pretty close to flat.

 

[frankenstien]

no more issues after welding the tabs to the tube, removed my add a leafs today and replaced the U bolts with some 3/4'' ones