Hilux LN106 suspension plate mount buckled - cause for concern?

Also, if I'm not mistaken, the bolts look bent. Something not right there.

Thanks, Core420 and Frank. I see I'm going to have to do something about it! You're right, the driver's side bolts are bent; they're splayed along the length of the axle. They're EFS, if that makes any difference. The passenger side u-bolts (also EFS) are also bent; however, the ends haven't splayed apart, they've bent away from the axle on both sides. I'm beginning to think they're designed to bend a bit?

A guy below suggested to straighten the perch and pack it with a wedge or something. I think I'll go down this route. Hope it'll hold for a few trips until I get around to fixing it....

Cheers,
David

Check with the manufacturer but any suspension U bolts I've used are to be ditched and replaced once the tension comes back off. Are you missing a backing plate for the perch to spread the load out maybe?

As a now retired Automotive Engineering Tradesman I was taught to never place a nut onto a bolt , or a bolt into a threaded fitting, unless there was some form of lubricant placed on the threaded portion.

This lubricant should preferably be one as specified by the component manufacturer, but in the absence of a manufacturer specification then light grease or light engine oil was sufficient.

In addition to this lubricant the thread must be clean, and the correct torque applied. There are also instances of bolt length being measured and the bolt tightened to achieve a specified amount of bolt stretching, this is often the case with Aircraft applications.

In the case of axle U bolts the correct tension/stretch/clamping load being applied must be greater than the maximum load that will ever be applied during service. Should you find a broken U bolt in service then it was most likely UNDER torqued at original assembly, as the correct stretching of the bolt would have shown up any weakness or flaws in the bolt during assembly.

In the case of axle U bolts it is possible to bend the axle tube (on some vehicles) if the bolts are over torqued/tensioned.

Regards
Athol

Thanks, Gbc.. - I'll be sure to get new u-bolts once I've straightened and reinforced the perch.

Cheers, Athol. I used a very thick, claggy grease (Lanox MX4 Lanolin grease) on the threads. It's pretty damn hard; you have to lever it out with a screw-driver. The consistency is such that if you tried to spoon it out, you'd bend the spoon. Should I use a lighter grease for this application? Always thought that it was a good all round grease. Will be more particular about keeping the threads clean when I install the new u-bolts - thanks for the tip.

The bolts do seem to have stretched - the legs are no longer the same length.

Cheers,
David

David.
AS this vehicle is an off road vehicle, and could feasibly be used on a beach at some time, then something like Never Seize (Nickle Coat) or Copper Kote applied to the threads will give the required lubrication AND resistance against corrosion and rust forming within the threaded section (meaning that you will be able to remove the nuts in the future).

DO NOT USE Copper Kote if the vehicle is likely to be used in or near a Coal Mine site, as coal dust and copper sets off a chemical reaction that is not pleasant.

The grease that you are describing sounds like it is intended for the fifth wheel turntables used in heavy road transport.

Regards
Athol

Thanks, RMD. The perch is a little pitted on one side (I tidied this up and the material is still plenty thick). I like the idea of reinforcing it - the rear axle perches are reinforced with a hard-setting material by the looks of it. I'll do this - cheers.

The other side seems to be okay. There's no perch, the plate simply mounts up against the axle housing. There's only a perch on the drive's side because the diff is in the way.

Cheers,
David

Thanks splits, but I'm very sure the perch wasn't bent off-roading. I spent a lot of time under the Lux installing new leaf springs, and I would have noticed if the perch was bent. I think the fact that the perch is somewhat pitted has weakened it significantly. I incrementally torqued the nuts until they wouldn't budge, by the way - I placed my feet against the wheel to brace myself and really wrenched on them! Read somewhere that they're supposed to be ultra tight, but have second thoughts about this now. Perhaps 90 - 120Nm isn't too hard to achieve with a ring spanner after all.

I'm going to get new u-bolts and reinforce the perch. I used EFS bolts, but will probably try genuine Toyota bolts this time round, as you've suggested.

Cheers,
David

David. Do yourself and your car's nuts and bolts a favour and get yourself a tension wrench. Keep your feet for walking and running.

At the moment the workshop manual for my 106 is packed away somewhere due to us moving house. I do have the manual though for my LN167. The tension for the rear U bolts is 120 nm. Your front bolts are most likely the same.

I have been using an old $25 second hand Warren and Brown wrench for years on all major bolts and nuts on both of my cars. I had previously used identical wrenches in both the motor industry and the RAAF. A new one cost around $250 at that time.

I took it to a torque calibration company in Sydney and watched them overhaul and adjust it to within 1 psi accuracy.

You may be able to do something like that or you could buy a new one. Whatever you do, make sure you get the a good one.

Splits..
Is PSI a torque measurement?

RMD - I think splits had a bit of a brain fart and meant to write "1 lb/ft". We've all done that.

And torque is measured imperially in "pounds-feet", not "foot-pounds" as many are wont to say.

Cheers, Ron.