Warning: Breaking steering arm bolts!

[ingthorsson]

This may well be old news, but I thought I should share this:
I was recently rebuilding the front axle of my sisters ´95 80 series LandCruiser, simply because of oil leakage, and discovered that two of the four bolts that hold the steering arm underneath the passenger side knuckle were broken. A visual inspection did not reveal this ´cause the cones that go around the bolts held them in place. This particular LC is totally stock except for 33" tires, maybe a slight lift to acommodate the tires.
NEVER DRIVEN OFF ROAD! Just an in town commuter for my sister and her kids. It was a shock: Toyotas are supposed to be practically inf***ingdestructible.
I spoke to one of the main builders at Arctic Trucks and he told me that this was not unknown on big-tired off-roaders, but a street vehicle????

The driver side is less suspectible of course, but still............

My personal theory is that the bolts are too strong, that is to say that they "feel" like 12.9 bolts, and that may simply be too brittle for the side loads they are subjected to. I´d rather use 10.9 bolts for this kind of application.
They would have to be specially made because the threads are two different non-standard threads: 1.5mm for the knuckle end and 1.25mm for the nut end, while standard 12mm threads are 1.75mm.

I´d be careful though about applying that theory; questions about liability might arise if it´s wrong.
Icelandic engineers accept 10.9 bolts in this kind of applications if the threads are rolled, with cut threads the bolts must be 12.9.

So if you drive a Toyota with the steering arm bolted onto the knuckle;
Check out the bolts: Simply try turning them with a short wrench or ratchet. If they´re broken, they´ll turn rather easy. If not, it takes quite a force to move them as they are tightened to 95Nm.

Ingthorsson.

[softy]

I just had a similar problem with my 80, but i went one step further my studs from my steering arm striped out & i lost my passenger side front wheel & every thing from the cv housing out went under the car.

I was lucky that this happened in the bush when i was driving on soft sandy dirt driving only 5klm. How did you end up fixing your sisters truck your imput may help me to fix mine so it does not happen again.

[softy]

I just had a similar problem with my 80, but i went one step further my studs from my steering arm striped out & i lost my passenger side front wheel & every thing from the cv housing out went under the car.

I was lucky that this happened in the bush when i was driving on soft sandy dirt driving only 5klm. How did you end up fixing your sisters truck your imput may help me to fix mine so it does not happen again.

[ingthorsson]

Hi Softy.
I´m sorry to say that I couldn´t come up with any alternative other that new standard bolts.
The guys at Arctic Trucks had no other alternative either, although they were familiar with the problem.
I didn´t eyeball the room to play with for larger bolts, but it might be possible to drill and tap the whole thing up to 14mm.
Studs and cones in 14mm could be hard to find, I´d check for that with a friendly Scania dealer.
I´m pretty sure that if one could install 14mm 10.9 studs that would end the problem once and for all.

My sisters truck has admittedly gone a bit over 300k, so some metal fatigue can be expected, so untill she sells her 80 ,
I´ll make sure to check those bolts every now and then.

Ingthorsson.

[beanz2]

If 80 steering studs are shared with the 40/60/70 series, there is a high strength version available from this link



IIRC the size and thread pitch is the same as what you described.

Dave

[80UTE]

These replacement studs look and sound good and coming fro ARP they have been making hi-strenght fasteners for a long time. I found that the replacement studs from Toyota are different to the one's originally fitted and have a 6 sided star that uses a 8mm on the end to assist in the instalation. I replaced mine on my 80ute and loctite primed and installed them with loctite 262. Mine have been in for 3 years running a B/Block and 38" tyres and never had a prob but i do reguarly put a spanner on the to check the nuts are tight but have alwaqys found them tight.

Wally

[ausyota]

I installed the FROR (ARP) studs onto my knuckles and my freewheeling hubs on my diff that will be going in with my SAS.
Hard to say how good they are yet but heeps of people have very good things to say about them on Pirate.
The knuckle studs are slightly longer than originals. They have been made that way to suit the added thickness of some High steer arms.
They also come with "conelock nuts" (also known as prevailing torque locknuts) which are a high tensile all steel locking nut.

Some people on Pirate have fitted larger studs (9/16) from a Dana knuckle as a different option and some have fitted an extra stud or two.
http://www.pirate4x4.com/forum/showthre ... light=fror

[softy]

Thanks For the help guys with my problem, I will look at changing my bolts & putting a bit of lock tight on them & hopfully I will not lose my wheel again.
I have just one question, because my studs striped out of the knuckle can I tap a bigger thread in so I can put a bigger stud in ?
Or will this make another problem with the cones because I will be going a different diameter stud ?

[beanz2]

You can put a larger stud in, but it would take new cone washers and possibly machining the steering arm to accept the larger studs and cones. The US favorite to use in this route is Dana44 steering arm studs:



much larger than Hilux/40/60/75 studs:



I don't know much about 80 series swivels though, but I believe the steering studs are identical. Dumbdunce? Ruff?

Dave