axle truss?

[unoleisu]

Ok. I'm about to do a 8.8 axle swap into my 87 BII. While I'm relocating perches and shock mounts, I thought about going ahead and doing trusses. I'm trying to decide weather to bother with it, or not. Is it going to be worth the trouble? Do I need them, will I gain anything?
Thanks. I doubt I'll be rock crawling, just occasional rougher offroad. Mostly DD.
Thank:icon_welder:s

 

[Guilius]

it never hurts, but the real question would be why?
when you do your 8.8 put a bead of weld around the tubes where they hit the diff housing. they are just pressed in and this will really help. go slow...do a small bit at a time and let it cool... do one side then the other.

but if you just want a truss because....... there's many to choose from.
here's a cool one.
http://www.undercoverfab.com/truss-systems/92-ucf-dana-44-rear-truss-system.html

and another from one of my favorite stores.
a truss wit tabs. you can leave the tabs off and just use the truss.
http://claytonoffroad.com/product_info.php/cPath/17_53/products_id/131

 

[88_Eddie]

light offroading, i'd say no. an 8.8 is pretty darn strong. but you could do it anyway, just incase you wanted to do a doubler down the road. what size tires you running?

 

[59bisquik]

If your gonna swap it in, you might as well do it. Its not that much extra work. Speaking from experience, I have twisted a tube in a 8.8. Granted I do have a doubler, 35's and wheel some pretty crazy trails.

Here is a quick pic of mine... not the fanciest... but it works!

 

[4x4junkie]

Did you have your tubes welded to the chunk when it twisted?

 

[59bisquik]

Junkie...
Nope it was just a stock 97 Sploder housing. Now I weld the pumpkin and tubes in a few spots and added a truss for extra precaution.

 

[4x4junkie]

10-4.

Yeah the truss definitely doesn't hurt, though I also would say IMO that unless you plan to be jumping it (truss it along the bottom), or building a 4-link suspension (overhead truss like 59's or the ones Guilius posted links to), it's probably something not really needed. For sure do weld the tubes to the chunk though.
Spun tubes is a well-known issue with 8.8s used hard, they only have 3 small plug-welds holding them in.

 

[cammeddrz]

when you do your 8.8 put a bead of weld around the tubes where they hit the diff housing.

welding the tubes in your back yard can do little to no good at all. welding mild-steel tubes to a cast-iron housing requires the proper use of pre-heating in the right spots or else it just makes the weld (and the surrounding metal) more brittle than it even was to begin with. i wish i had a dollar for every mustang guy around here who just blasted a bead around his 8.8 tubes. just to tear the diff apart right there before even hitting the 60-foot line at the drag-strip

 

[59bisquik]

Actually, I used Protectic 4026N high nickel alloy rod to weld mine. Its expensive at about $25 dollars a pound and we use it at work on very large diesel engines with cast steel blocks. Only draw back is that it is very hard to find.

 

[CHKNFKR]

If you plan on abusing it truss it along the bottom. No matter how strong you think your truss is, the fact is it's far more likely to crumple on top than stretch on bottom. If the couple inches of lost clearance are a problem for you get taller meats.

 

[86 slo-vo]

welding the tubes in your back yard can do little to no good at all. welding mild-steel tubes to a cast-iron housing requires the proper use of pre-heating in the right spots or else it just makes the weld (and the surrounding metal) more brittle than it even was to begin with. i wish i had a dollar for every mustang guy around here who just blasted a bead around his 8.8 tubes. just to tear the diff apart right there before even hitting the 60-foot line at the drag-strip

the center will hold fine when welded, keep trying though.

 

[Sasquatch_Ryda]

And it is cast steel, not iron.

 

[unoleisu]

Hmm, ok, those are some things to consider. I did plan to weld the tubes, and I think I will go ahead and build a truss. Ya never know when I may get adventurouse and need that extra support. I might go top AND bottom, but I haven't seen too many good examples of bottom trusses, mainly "smack plates" or whate ever the really thick gaurds are called.....

59bisquick, does that second pic show the forward support bolting on to the pinion housing?

 

[unoleisu]

My budget currently allows me to keep my 29" tires, but plan to run 31" or maybe 33" in the near future. I'm concentrating my resources on mechanical upgrades at the moment. After the 8.8 install, I'll be working on a D35 swap. Then the 4.0 swap.

I already replaced my A4LD with an '94 EXP M5OD. I have my BW1350 E still in the truck, but a BW1354 E sitting on a table, waiting for me to decide when to put it in. (I'd rather go manual, but haven't found one locally yet.) Anyway, going one step at a time. Trying to do it as right as I can, while I'm doing it the first time.

 

[59bisquik]

59bisquik, does that second pic show the forward support bolting on to the pinion housing?

Yes, I used the 3 bolt pattern next to the pinion to attach the truss.

I might go top AND bottom

Most dont truss underneath unless they plan on jumping it, also it limits your ground clearance. I rotated my shock mounts and everything else up so nothing is hanging down to get snagged.

 

[unoleisu]

59bisquick, I appreciate the help. I saw the shock mount rotation, looks like a great idea. I noticed on my original axle that the shocks are actually at a (6 deg. ?) angle as well. Did you maintain that, or do something different?
Also I can see new bolts on the frame at the shock mount, did you change that? If so, how and why?
Oh, and What did you do about your breather vent tube? Couldn't see it in the pics.
Thanks for the response!

 

[59bisquik]

As for the lower shock mounts, I just rotated them up until they were parallel with the ground. When they hung down, I used to catch them on rocks.

The reason you see bolts on the frame instead of the the rivets, to use Fox shocks, I had to modify the upper shock mount. The Fox shock uses 1/2" bolts to mount them and the upper mounts on the bronco are bigger. I cut them off, added 1/2" bolts and spacers. Once you get into valvable/rebuildable shocks like Fox and King, you will never use standard shocks again!

The axle vent is still there, its just longer and still ran like stock. I am going to try the Toyota style breathers instead of the hoses when I get a chance.

 

[unoleisu]

Thanks for the quick response, 59bisquik. I have been looking around in my scrap metal piles, and I think I've desided to do something similar to your setup. Originally I planned to use some 4" round tubing I had, but It didn't seam to be thick enough. I have some thick square tubing about the size you used, but I think I'm going to take it out to just next to the u bolts. Instead of welding directly to the tube with that, though, I've got some round stock that will fit onto the axle tube with a bit of tweaking (4 1/2") . (Been thinking about doubling the tube underneath, haven't decided yet). So, I'll weld the square stock onto it, and then weld that onto the axle tube, about half round. That way, I'm distributing the stresses more. That's the current plan, anyway. I ran out of welding wire while welding the tubes, so what I thought I'd finish today, will continue tomorrow.

 

[59bisquik]

Post up some pics once your done. Im having trouble picturing what your gonna do.

As for the truss, i put mine right next to the pumpkin since my only concern was to stop the tubes from spinning. I wasnt worried about stiffening the whole housing.

Also, with it in the middle, I have been toying with an idea of adding an airbag to the top of it. I have seen buggies with them, you can lift the vehicle when extra ground clearance is needed or you have a little cargo. With it in the center, you dont have to worry about flex.

 

[unoleisu]

I'll do my best to get pics all the way through the project. I forgot to take a "before" picture when I started, but I think most people don't care what an 8.8 looks like when just pulled from the doner. I'm having trouble with my camera turning on, Had it repaired twice and still just won't turn on for about 15 min of trying. When it finely does, it works fine. That was $350 that could've been spent better.

I got a mock up pic yesterday, I'll try to post it after I get back from my welding wire trip in a little bit.

Air bags sounds cool, but probably outside of my range for now.