Outer Limits 4x4 Board

Why does my track bar want to break it's mounts? I've attached a couple of photos and am hoping that someone could help me out. The vehhcle is a hilux with an underpowered 2.4L petrol motor and stock gearing with 33" tyres. Initially I welded the the arm to the diff housing and it was ok for a couple of days driving around town but then I went to Manar park which is about a 5hour drive. When I got there I realised that the welds on the top of the diff had started to crack. I wasn't too concerned as I hadn'd done any particularly strong welds there and though "oh well, I'll reweld it when I get home - all good". I should state that the drive there did cover some bumpy roads as well as cattle grids and dirt roads and although the suspension wasn't being fully flexed, it did get a workout.

By the end of the weekend at manar, both welds at the top had broken and the weld running down vertically beside the diff centre had started to crack.

Later when I got home I rewelded it with about 5 runs with a 3.2mm rod with big fat beads and I thought to myself "now that won't break!"

Last weekend I went out to ormeau and throghout the day I noticed that the weld was breaking again - much to my surprise. On the way home I called at Ruff's house and took him out to show him the situation and get some suggestions. When I got out there I realised that the bar had totally broken all welds at the diff housing and was floating. As such it had got in the way of my 3 week old rancho 99036x shocks and totally stuffed it! Apart from being p1ssed off I still couldn't work out what was the reason behind this. The springs that I have are reasonably flexy but they are quite stiff and do have load leaves installed.

Ruff believed it was just not enough bracing but I have doubts. I believe that it may be something to do with the way my suspension cycles and as such the track bar isn't set up according to this. The shacke is fixet to the chassis at the top and the track bar at the bottom. Most are the other way around. Would this have an impact? When fitting it I also dialed in a bit of preload so that when I hit the gas, the shock from the heim joints taking up the slack wasn't as pronounced.

Should I just reweld it and remove the shackle then cycle the suspension and se how much the front end wants to move?

Should I give up?

Should I stop playing around and go a 4 link rear?

Anyone help?

And before anyone else says it - I know that I may be due to my welding but it's the best I can do. Those spring hangers that are visible in the pics were welded by me and they're still there.

pics - then we may be able to help

I'm trying dude!

Computers suck!

email them to buddy@buds4x4.com if you can't do it

I've been trying.

No wonder I can't design a decent track bar when I can't even work out how to post a picture!

I've tried emailing buddy but I'm being told that someone or something "can't find server" so I'll try again this afternoon.

4 link it

just kidding

my wrap bar is attached to the bottom of the shackle and its never torn off?

the only difference should be if it is trying to compress or extend the shackle under load. There shouldn't be any difference at the axle end??

its probably the angle/the way you have your track bar set up.
When your leaf springs compress, the diff move rearward a litttle, if your trackbar is trying to keep the diff in the same position, and the springs are trying to move it rearward, your weld will suffer
the best track bar has 3 points, and is attached to a shackle just like the springs are

It will look like a A frame put in sideways, if you do a search on the net you should find some good links on it.

Jes

if its cool...i might drop round later tonight beebee and cast an eye over it if you like

jessie928 wrote:
It will look like a A frame put in sideways, if you do a search on the net you should find some good links on it.

Jes

If you read his post, that is exactly what he has built for himself 8)

I just tried to email these pics to bubs again but still no glory! I will keep trying.

jessie928
This is the way that it is built. The two rear heim joints are basically perpendicular to the diff centre, the top link is very close to horizontal and the shackle angle is pointing at about 12.30 - 1.00 from bottom (track bar mount) to top (chassis mount). Ant the bottom link runs nearly parallel with the driveshaft.


Punchy
I will be out this afternoon and tonite but if the ute's out the front...come on in!

BJ
what angle is the shackle in yoiur setup?

Thanks for everyone's help!

I ran one on the boatlux and never had a problem, some pics are needed!!!!!!!

I've got the pics.....they're even scanned and saved to my hard drive. Do you think I can attach them to an email - fu(k no!

I try and attach them and after 15min they are still unattached.

I'll try zipping them as maybe the file size is too large?

How far apart are the joints on the axle tube?? How did you construct this?? How much weld did you get on the diff (length)?

Pics would be nice.

Sam

beebee wrote:I've got the pics.....they're even scanned and saved to my hard drive. Do you think I can attach them to an email - fu(k no!

I try and attach them and after 15min they are still unattached.

I'll try zipping them as maybe the file size is too large?

Usually after scanning (depending on your settings) the file sizes can be quite large.

Open them in your photo program and resize and make the file size smaller (60 - 80%)

Then try attaching to an email

beebee wrote:I've got the pics.....they're even scanned and saved to my hard drive. Do you think I can attach them to an email - fu(k no!

I try and attach them and after 15min they are still unattached.

I'll try zipping them as maybe the file size is too large?

straight up and down is the only angle to have

upload them to a ftp site ..like you internet web page site that your isp gives you..and link to it...

i went around and had a look at beebee's gear today
Hmmm
confusing as to say.
But we threw a few ideas up in the air and we'll see where it all lands

booger weldz

Sam,
the two mounts at the diff end are 150mm apart and pretty much verically on top of each other. The top link is 1055mm long making the lower?(can't find my calculator). The bottom mount (at the axle end) is about 50mm of the top of the housing and the crownwheel is 8" (200mm) so the top mount is probably about 250-300mm above the axle centre line.

I believe that it occurs due to suspension travel rather than wrap. As the suspension compresses, the bar is required to remain perpendicular to the axle or the direction of travel. As the front end is relatively fixed, it tries to pull the front of the arm down when the axle goes up (relative to chassis). This creates the force requird to break the weld at the rear of the housing and thus it continues until the weld is completely broken.

If the diff housing mounting was completely rigid, the housing would be required to rotate downward under compression and upward under extension much like a radius arm type of linkage. As the leaves resist this rolling, the bar departs from the axle housing.

I can't understand why others are having success with this setup and I'm not. Sure it's theoretically flawed but in practice it works for everyone else. At the least it must be limiting travel.

All of these statements refer to a track bar that is mounted above the diff center as I believe that one mounted with one link above and one link below the axle is a whole different kettle of fish.

NICK wrote:booger weldz

If only they were that good!

I'll let you know when my front forward spring hangers, rear forward and rear spring hangers and spring perches fall off! (all booger weldz!)

Does anyone else have some shots of their wrap bars as I am gonna be doing the same soon & wouldn't mind some ideas. I know it's prettty straight forward but at the same tim I'd rather make sure

beebee wrote:I can't understand why others are having success with this setup and I'm not. Sure it's theoretically flawed but in practice it works for everyone else. At the least it must be limiting travel.

Could the fact that your springs are reversed have anything to do with it? Maybe magnifying the forces acting on the welds? I havent really thought about the physics of it all, I cant really be bothered right now. Just throwing it in as a thought. Are there any makes that have the axle mounted in the rear of the spring as standard? Do they have similar problems?

John

beebee wrote:Sam,
the two mounts at the diff end are 150mm apart and pretty much verically on top of each other. The top link is 1055mm long making the lower?(can't find my calculator). The bottom mount (at the axle end) is about 50mm of the top of the housing and the crownwheel is 8" (200mm) so the top mount is probably about 250-300mm above the axle centre line.

I believe that it occurs due to suspension travel rather than wrap. As the suspension compresses, the bar is required to remain perpendicular to the axle or the direction of travel. As the front end is relatively fixed, it tries to pull the front of the arm down when the axle goes up (relative to chassis). This creates the force requird to break the weld at the rear of the housing and thus it continues until the weld is completely broken.

If the diff housing mounting was completely rigid, the housing would be required to rotate downward under compression and upward under extension much like a radius arm type of linkage. As the leaves resist this rolling, the bar departs from the axle housing.

I can't understand why others are having success with this setup and I'm not. Sure it's theoretically flawed but in practice it works for everyone else. At the least it must be limiting travel.

All of these statements refer to a track bar that is mounted above the diff center as I believe that one mounted with one link above and one link below the axle is a whole different kettle of fish.

Difficult without pics, but I would say you need to mod it so that the welds in this area (rear of the housing) are loaded in shear rather than tension.

Hybrid,
the reversed springs (with pin toward rear of centre of pack) shouldn't affect things too much. All it does is increase the chance of axle wrap.

2car,
that is probably a good idea and would be the way that I'd go but I feel that if I reinforce this connection so much that it doesn't break, then I'll be limiting flex. The suggestion that you made about shear as opposed to tension was what ruff said but using words such as "bit of steel" and "goes there" and "bird shiat" - just so I could understand!

beebee wrote:Hybrid,
the reversed springs (with pin toward rear of centre of pack) shouldn't affect things too much. All it does is increase the chance of axle wrap.

2car,
that is probably a good idea and would be the way that I'd go but I feel that if I reinforce this connection so much that it doesn't break, then I'll be limiting flex. The suggestion that you made about shear as opposed to tension was what ruff said but using words such as "bit of steel" and "goes there" and "bird shiat" - just so I could understand!

I am guessing your mount is basically two plates welded to the diff housing and the trac bar mounts between them.

Right at the back where the plates separate from the housing, weld in a bit of plate across the top of the plates that are already there. Make the new bit long enough so that it continues back past the end of the mounting plates and down the back of the housing. Bend the new bit so that it sits on the housing and weld along all edges. Capische?

That shouldn't limit flex at all, but without pics we may be barking up different trees.

Another attempt at a pic or two.

More pics

2car

Are you basically suggesting something like a "strap" going down the back of the houising? I guess that this would be much less stressful than the current system.

beebee wrote:More pics

2car

Are you basically suggesting something like a "strap" going down the back of the houising? I guess that this would be much less stressful than the current system.

Yep.

that will be breaking the welds because of the leverage on the mount

you need to brace it.

Is that due to axle wrap or suspension articulation?