Broken front torsion bar mount in OZ, anyone heard of this?

100 TD · 10-30-09, 06:39 PM

There may be others but I don't recall them.
From LCOOL
Story is, they have taken the vehicle out for a short test drive after installing new fusible link. Vehicle is few hundred metres from workshop and suddenly pulls over to left. Appears that there is problem with front suspension.

Here's the problem! No more info yet but I'm hoping he will ring me.
It appears that it may have been loose and flogging a bit, hard to tell with just this pic, will be interesting to see what the other bolt and tab look like as well as any wear marks on the bolt.
The interesting bit to me is the "Clean break", looks like it let go at once, hard to tell though by a pic.

NMuzj100 · 10-30-09, 08:45 PM

Quote:

Originally Posted by 100 TD

Story is, they have taken the vehicle out for a short test drive ...

Who was doing the test drive ? The proud owner of the premium off-road machine or a shop technician free for a few minutes from the stifling shop and his overbearing boss? Huge difference in driver behavior!

Looks like a freak failure. Either a bad casting from the get go or metal fatigue (How many corrugations are there in an outback kilometer?).

I wonder if that mounting nut could have been over-torqued damaging the mount. It looks like it has been on and off before.

100 TD · 10-30-09, 09:07 PM

A few hundred metres from the shop after installing a new fusible link says it's on bitumen going around the block to me.

I thought about the over tightening and possible cracking, but it appears to have been loose to me from the pic. Hard to tell, I will speak to him and learn more if I can. (see the rust and burring of the casting where it meets the arm)
Realistically though, tension is ALWAYS on this in one direction, at no point is there tension in the other direction. It doesn't matter how hard you drive the vehicle either, this is part is just having pressure applied to it by the torsion bar from max flex to minimum flex, it doesn't come to a stop or a jolt, it just has varying pressure applied to it all the time. I'm interested to see if either bolt was loose, as the picture suggests, as this would have allowed some slight twisting which could have been detrimental to it.
The other thought I had was that when it has been reassembled, the block wasn't square or fitted/aligned correctly and therefore strain has be placed on it and it snapped. This could have also happened if someone not knowing much about the principal of IFS undid the nuts with tension still on the bar, found they couldn't do anything then did them up again. This would have most likely strained the casting as it was done up as it would not have aligned correctly.
The other possibility is that the lower arm has flexed enough to assist this happening. Hard to tell without examination.

hzj80cruzr · 10-31-09, 04:25 AM

Hi All,

I am the owner of this vehicle. A 2004 1HD-FTE Sahara auto.

There can be many asumptions made on what caused this. In all fairness, the vehicle has done 130,000 km with no IFS mods. (probably a fair bit of outback driving with the family, but I do not think any hard core stuff) However the weight at the front of the vehicle has 3 batteries under the hood, a WARN 12,000 lb winch and an ARB Safari Bull bar. So, a fair bit of weight. The only mods are OME springs and shockies with aftermarket torsion bar tightened, probably too much.
I have only owned the vehicle for 2 weeks. Yes it is possible that the boss owner mechanic got one of his rookie mechanics/ work experience bods to check underneath when it was getting its 130,000 km service. They may have unknowingly done the wrong thing or were too lazy. It is a hard thing to prove. Unfortunately, the boss owner/ mechanic is currently in Les Vegas until mid November so I am unable to tackle him on this until his return. I have a good relationship with the owner.

I have been lucky to get a part from the wreckers today, so this will get me back on the road until such a time I get the new ones from Toyota. I will replace both front torsion bar mounts before IFS upgrade. At the same time I get the IFS strengthened/ welded with the brackets, new torsion bar, drop diff and new cross member as well as some Bilstein shocks and springs, yet to be determined.

It's a great vehicle, very nice to drive.

[IMG]file:///C:/Documents%20and%20Settings/Kym/Desktop/2004-100-series-IFS-Safara.jpg[/IMG]

I also own a 1996 80 series. Trying to think of a reason to keep the 80 but running two 4wds can be a costly exercise.

All comments welcome

cheers

Kym
Downunder

MidTex · 10-31-09, 07:49 AM

Good looking rig.

farinvail · 10-31-09, 10:30 AM

nice rig. isn't there 2 mounting bolts for the t-bar? did they forget to install the inner or is it different in OZ?

100 TD · 10-31-09, 06:58 PM

The other bolt is behind the bar, that is what is still holding the bar in place.

UltraFJ · 10-31-09, 07:55 PM

Captain obvious here, but 130K of beating on the rig doesn't leave much to be beaten. I think you pretty much drove it to the breaking point and luckily, it happened when being at the shop.

Continuous wear and tear (stress) will break any metal forge eventually, including Mr. Yota's forges.

Yotato · 10-31-09, 10:59 PM

That can also happen when a jack is placed on the torsion bar instead of the frame. My brother learned the hard way last month.

100 TD · 10-31-09, 11:08 PM

Quote:

Originally Posted by UltraFJ

Captain obvious here, but 130K of beating on the rig doesn't leave much to be beaten. I think you pretty much drove it to the breaking point and luckily, it happened when being at the shop.

Continuous wear and tear (stress) will break any metal forge eventually, including Mr. Yota's forges.

At 130000kms the rig is just getting run in.

Quote:

Originally Posted by Yotato

That can also happen when a jack is placed on the torsion bar instead of the frame. My brother learned the hard way last month.

Now this sounds a lot more possible since it was in the shop for a service the week before!

hzj80cruzr · 10-31-09, 11:37 PM

Quote:

Originally Posted by 100 TD

At 130000kms the rig is just getting run in.

Now this sounds a lot more possible since it was in the shop for a service the week before!

I never even gave this any thought, but as suggested, certainly very possible, whether I can prove it a week later, I doubt it !

Just gotta love these forums for the experience and knowledge that others can share.

cheers

Kym (the owner of said vehicle)

Clint79 · 11-01-09, 05:28 AM

I have heard this from a few suspention mobs that say as soon as you put after market torsion bars for lift it streeses the max out of the rest of the sus and brackets

spressomon · 11-01-09, 07:14 AM

Quote:

Originally Posted by 100 TD

At 130000kms the rig is just getting run in.

Now this sounds a lot more possible since it was in the shop for a service the week before!

This sounds the most plausible since this is the first known issue and there are possibly a few others here, especially the AU guys, that may have been a little harder on their suspension components

.

1loudLX · 11-01-09, 05:15 PM

Spress, you're not too easy yourself on that 100!

Yotato's guess sounds the most likely.

KLF · 11-01-09, 05:29 PM

I have no experience with the 100-series IFS, but a lot with the IFS on mini-trucks. I have seen these mounts break on mini-trucks a few times, usually under extreme flex when the t-bars have been upgraded and cranked up a little. I remember being out on the Moab Rim Trail when I met up with a guy that was limping back to town, his was busted but he crammed a chunk of wood between the arm and bumpstop to hold it up, so after that I used to carry one of those mounts with me in my parts box just case.

It's been awhile since I've been under a 100, but IIRC the t-bars are on the bottom A-arm, not the top one as they are on mini-trucks. I can definitely see how jacking the truck up by the t-bar could snap that thing, it's not designed for that type of loading.

farinvail · 11-01-09, 07:12 PM

I believe this is the 1st thread regarding this break. And the majority of us have "upgraded t-bars" SO, really not a common problem with 100 series. Besides turning up the bar does not increase the load.

Clint79 · 11-02-09, 05:36 AM

Common with heaps of aussie 100's
i wonder why ..most people that but 100 series here arnt hard hard core offroaders, if they are they buy 105's or 7x series cruiser

100 TD · 11-02-09, 03:22 PM

Clint,
Perhaps you could enlighten us all to some information or a forum which shows where this is common or has happened often. I haven't read about it before, that is why the question is posted here. Any info would be great, especially if you have a contact in the suspension industry that knows of this happening often so we could as a few questions of them and learn a bit more.

Clint79 · 11-02-09, 04:17 PM

My old mans 100 series was pissing him of with the front hanging lower than the rear, so i phoned up a heap load of sus mobs for him and they all gave me the same answer, dont do it and gave me the same story of lifting then it straining then it breaking ,only seems to be 4x4 mags and shops that sell the products that say there good good thing, well the product might but what it does to the brackets might not be and two owners ive spoken to about there 100's with lifts have done the same but fairly heavy 4x4ing

So not to sure why ,could it be the early ones or something

hoser · 11-02-09, 11:51 PM

Clint, might you be confusing this with the cracking lower control arms?

Clint79 · 11-03-09, 06:24 AM

im thinking its the torsions bar mounts from memory mate
but cant exactly remember
Do the lower control arms have issues?

Texasoil · 11-07-09, 09:57 AM

Excellent photograph clearly showing the root cause of failure.

All these parts are highly stressed when in 'rough' driving conditions. Highly stressed cast steel and rolled steel are both weakened by pitting type corrosion (rust). What might appear to be insignificant in terms of metal loss, a pit can greatly increase the local stress to the point a crack begins and then propagates through the balance of the part that is not tough enough for the service. (toughness being a measure of high stress ductility--the ability to yield but not brittle fracture like that part did)
The photo shows a lot of rust under all the suspension fittings and fasteners,which is NOT good. I suggest you disassemble all the parts, clean up all the surfaces with a wire brush, then spray with a zinc rich cold galvanizing paint, then reassemble. replace any bolts that have pitting deep enough to catch a pencil point.

Texasoil · 11-07-09, 10:09 AM

Follow-up-- I owned several '126' series MBZ sedans--and the front 'torsion bar' was also the 'strut rod' to which the front top control arm attached, controlling the fore-aft movement as the inboard rubber bushing was huge and would not restrain fore-aft movement at all. That torsion arm developed pitting corrosion under the rubber bushings where it attached to the control arm. I found myself measuring and estimating the amount of good metal remaining and calculating its loading capacity remaining (R&R of the torsion bar was a 22 hour book time job!) I suddenly realized the stupidity of my approach--loss of that attachment in a sharp turn (when it would be most stressed) could easily cause loss of directional control--leading to an unplanned exit from the top of a freeway interchange followed shortly by an abrupt stop as the car (and occupants) impacted the ground maybe some 80 feet below. On this realization, I went inside and drank a 6 pack , accepting the fact the corroded torsion bar had to be replaced. When in doubt, change it out is my firm mantra now with ANY component that is needed to steer, brake, or otherwise control the direction and location of the vehicle. Not quite to aircraft standards, because failure to 'go' is not life threatening like in airplanes. (Landings are mandatory, take-offs are OPTIONAL)

hzj80cruzr · 11-13-09, 03:18 AM

Thanks all for your replies. (from the owner)

The jury is probably still out on the root cause of this problem. However, the group consensus, and I'm speaking experts in this field, that amongst them, have litterally converted thousands of LC100 IFS. They agree that the bolt (as per in the photo) was more than likely loose exacerbating the problem. In addition, when I had the torsion bar mount replaced, the front control arm LHS was also replaced due to severe cracking and twisting of metal. This was un-expected news, as well as cost, and was not discovered until the car was on the hoist and covers were taken off exposing said problem. At a later stage with the vehicle on the hoist again, the mechanic and myself spent over an hour with LED lights and mirrors into hard to see spots checking all other vital components, hoses and pipes for possible gremlins that may be awaiting me. Good news is that the underside of the vehicle appeared okay which makes me feel better.

So what next; the car is booked in for a much needed upgrade to the suspension. (currently the suspensiion stuff on there is about 120,000 kilometres, so best to start on a fresh clean slate). Surprisingly my wife has not objected to spending these additional funds.

I'll be looking at Bilsteins long travel with specific valving and stone shields, Ridepro torsion bars and Ridepro springs on rear, new Toyota/Lexus bushes and a Slee off-road Diff drop X member + the all important strengthening mod, stitch welding a bracket to the lower front control arms.

All of this will not be happening until 21st December, which is when the car is booked in.

The aim of this is to transform this cruiser into a very capable heavy duty touring vehicle, ready for those huge around Australia expeditions.

I'll post another report in the New Year on the mods and will also do a before and after measurements of the height difference front and rear.

cheers all

Kym