Craig B: Sheared trackbar mount on the front axle

[TRBN8R]

Hi All

Got a call from Craig B yesterday. He doesn't have internet access at this time so I am posting him on his behalf.

He sheared the front Trackbar (Panhard Rod) mount driving on the road. Jeep quoted him $4900 to fix it. But agreed to fix it under goodwill as he had complained the loss of steering control at the last service and they failed to diagnose it. But he reckons Jeep Australia is not going to honor any more warranty claims of the similar nature from any Jeep fitted with lifts without adjustable trackbars. Jeep reckons with a 2 inch lift the trackbar tries to pull the axle out to one side but the control arms try to keep the axle centered under the chassis. Thus creating a constant tension on the trackbar mounts, leading to fatigue in the welds which crack over time.

Any suggestions how to avoid this.

Mani

[Steve F]

What a load of crap from Jeep. The control arm bushes are rubber, if the panhard mount breaks before the bushes tear up and flog out there is something seriously wrong with the welds those Chrysler robots are laying down!!! Sure there will be constant tension but even the panhard is rubber mounted at the diff, there are just too many rubber mounts for them to suggest the stress on the weld will cause the bracket to rip off especially at 2" of lift. Now if Craig has had some serious death wobble and it hasn't been resolved there could be some high shock loads on the mount that could fatigue the panhard mount and the welds but really the steel should tear before the welds let go. Oh, and $4900 to fix it, he could get it welded back on better than stock for a lot less than that!!!

Hmmm, that rant doesn't really help does it ;) I guess the only answer to keep Jeep happy is an adjustable panhard.

Cheers
Steve

[Miraz]

+1 utter nonsense from CJA again...

[Wooders]

Jeep reckons with a 2 inch lift the trackbar tries to pull the axle out to one side but the control arms try to keep the axle centered under the chassis. Thus creating a constant tension on the trackbar mounts, leading to fatigue in the welds which crack over time.
Any suggestions how to avoid this.
Mani
The control arms do SFA to locate the diff side2side under the chassis - that's why the panhard is there in the first place.
But really if the height is changed the panhard should be adjusted to suit.
Could be worse, they could say no warranty period.....

[Miraz]

Could be worse, they could say no warranty period.....

Could be better....they could stop making brackets out of cheese...

[tonysrich]

I don’t think the problem is as straight forward as just having adjustable trackbar/panhards. I have Rubicon Express adjustable trackbars front and rear but I have still had problems with my front trackbar bracket. The bolt hole has worn out prematurely just like it did on CraigB’s rig making the car impossible to drive with any degree of control and safety.

Jeep did a patch job under warranty on my car by welding some steel plate over the bracket and redrilling the hole to the correct size but that doesn’t address the real issue. The fact is that brackets are shit, they just aren’t thick enough to have the strength to do the job when the car is actually used for what it is designed for, off-road driving. This isn’t just my opinion either, it’s a common enough complaint on all the Jeep forums to realise that it is a serious design flaw.

I’m no suspension/steering expert at all but from what I’ve read on the net the original brackets both front and rear need to be replaced not only with more robust items but if you have any lift on your car you should replace them with raised brackets to compensate for the amount of lift you have. Adjustable trackbars may well centre the axle back to it’s proper position under the car but they don’t bring the geometry of the bars back to standard. Like I said I’m no expert but from what I can gather when raising the suspension it is important to bring the angels of all the steering components back to as close as possible to original to maintain the cars handling and steering characteristics Something to do with the “roll centre”.

Raising the trackbar brackets sufficiently to compensate for the amount of lift should, theoretically at least, correct the geometry enough after any lift to allow you to even use the original Jeep components . Having adjustable units are still a good idea though as they guarantee perfect centring of the axels. Mind you just what “perfect centring” is isn’t straight forward either. On the Rubicon Express site they state that due to the nature of the suspension geometry the axle needs to be slightly off centre as it moves to one side under compression. Mind you they don’t say which side or by how much the axle needs to be off centre, I emailed their tech guy but I didn’t get any response.

Having uncorrected syeering geometry could also a be possible (definite I reckon) cause of the infamous “death wobbles”. Any changes that you make to the suspension and/or steering can confuse the ESP system and cause it to not only activate unnecessarily but in a confused manner as well. I can speak from experience on this as it has happened to me twice. After finishing a run at Lithgow one time the car went berserk after only a few hundred metres back on the tarmac in 2WD . Turned out I’d done something to the steering which off-centred the steering wheel by about 20 degrees. Now as the ESP computer measures the steering angle not from the front wheels themselves but from the steering wheel and as mine was out considerably the dammed thing had a conniption trying to correct something that wasn‘t happening..

It happened to me a second time after a trip to Menai. I limped it home and had it towed to a Jeep dealer but it wouldn’t reproduce the behaviour for their mechanics. Their conclusion was that it must have been mud blocking a speed sensor and now that the mud had dried it wasn’t causing a problem.

My point to all this is that the ESP system can be upset easily by all manner of things and you should try “normalise” any mods you make as much as possible so as not to upset the dammed thing. It’s ironic isn’t it that a system that is designed to increase safety can try to kill you if it’s not working properly.

I was discussing these issues with Dave after the meeting at Wooder’s and asked him whether he carried raised brackets or could recommend any. He said that he didn’t but if he did he would be more likely to have them made up locally to his specifications rather than bring in items from the US. I’ll be taking him up on this so I’ll keep you posted as to what transpires.

[Steve F]

If you raise the panhard at the diff end then you also need to drop the steering at the pitman arm end, dropping the pitman arm means more leverage on the steering box and bigger tyres than stock means more again, maybe this will become the weak spot now. The panhard and steering need to run parallel to avoid getting bumpsteer. Once you start moving one mount around you have to compensate by moving others to keep the geometry correct. The other option is to raise the steering gear at the tierod end, so have it over the knuckle instead of under (assuming a JK is under the knuckle), all this sort of stuff should be engineered and is a fair bit of work. Also bearing in mind once you raise the panhard bracket at the diff there is a greater leverage on it and it will need to be substantial stronger to cope with this.

Anyway, just more to onsider if you do decide to raise the panhard mount at the axle or drop it at the frame. Because of all this my preference is to drop the panhard at the frame end and go over the knuckle with the steering. The frame bracket can be made as beefy as you like and OTK steering lifts it out of the rocks anyway. You just need to find a RHD kit that to do it.

Cheers
Steve

[tonysrich]

I'm sure that your advice is correct Steve but you lost me when you mentioned the "pitman arm". Steering, suspension and gearboxes, bloody dark arts that screw with your head. At least that is my excuse, like I said, I'm no expert, I’m just trying to figure out how to fix my rig because I don't trust anyone that makes a living out of supposedly fixing 4WD’s. Every bastard that has worked on my car has either done the job incorrectly or left out something crucial, like Macquarie 4WD did when they installed a 3.5 inch lift and 35 inch tyres but didn’t bother with extended brake lines or raised bump stops. So I’m trying to educate myself so I can do the work myself or at least know enough to tell if the job is being done properly.

You’ll have to take me out for a ride to the “Road Warrior” one day and see if you explain some of this dark science to me over coffee.