80 Series - Broken front diff housing

[p1michaud]

For the 80 series LC experts, a question I have for you.

Have you ever seen or heard of a front lower control arm mounting bracket break (right hand side) on an 80 series?

This is what I found recently, hmm where is this diff oil coming from?

More diff oil, can't be too good.

Further investigation lead to this.
Right hand side of bracket...

Left hand side of bracket...

I though that these 80 series were solid machines. On to of that, I though that I was easy and considerate of my equipment. I may need to reconsider this. :Wow1:

 

[p1michaud]

Diagnosis - impact caused break then fatigue caused cracking

Well after finding this issue, I had to investigate. With a few trips to the tool store for a new trolley jack and some jackstands and healthy dose of wrenching, this is what the underside of cruiser looked like...

I did not do too good a job from here on because I was elbow deep in diff oil and birf grease. In summary this is what I did with lots of help:

• Stripped the housing down (birfs, axles, swivel hubs, diff removed).
• Purchased a second hand housing that upon further inspection, I did not want to use as it was in worse shape that mine...
• Cut the broken part of the bracket off to identify the cracks and weld them up.
• Found this...
  
  
  
  If you are wondering, we used magnetic particle testing (a non destructive testing method) to find the cracking. That's why there is a white base with black indications. The grinder marks were an attempt to chase out the cracks before we gave up trying to grind them out and re weld each crack.
• Ground all of housing welds back, and welded a 5 mm fish plate over all affected area of diff.
• Adjusted bracket to suit new plate.
• Welded everything back in.
• Re-assembled the diff housing (birfs, axles, swivel hubs, diff)
• Installed axle under cruiser.
• Had wheel alignment done

My theory:

1. A large impact broke the right and left hand side bracket (before I owned the vehicle). Leaving minimal weld allowing the bracket to flex the diff metal.
2. The subsequent 40 000 Km's of daily driving plus 4WD adventures induced metal fatigue as the suspension did it's work and the corrugations worked their magic.
3. The cracks propagated through the entire housing leading to an oil leak.

A big thanks to my friends who assisted with the welding and magnetic particle testing. Without them, the cruiser would be without a front axle.

Out of interest sake, we did do more mag particle inspections on the diff housing and were a bit surprised at what we found. Lots of small cracks starting to form where the various brackets are welded to the housing. I'm curious to know if a new diff housing would have the same defects, I suspect not. If you have access to mag particle testing gear or dye penetrant and the knowledge to do the work it may be worth having a look at your diff housings...

The cruiser is now back on the road. :sombrero:
Cheers,
P

 

[CanuckMariner/Nomad]

It's good to know you found all the issues, however I am thinking it might have been better comfort and peace of mind to install a new one all the together. What with all the stress that the diffs and axle take, any small crack could develop into a pretty serious problem once you are out on the trail and then leave you stranded with a big towing bill.:costumed-smiley-007

 

[Sergio Castro F]

Broken brackets.

This situation is quite common in vehicles who twist the axles very often,but in your particular case, is enhanced by the use of caster correction busings,as i can see in the pictures .Polyurethane is 4 or 5 times harder than rubber and aditionaly the internal pipe of the busing is located very close to the external steel portion leaving almost no place to play, this is good on road but off road generates an excesive tension on the brackets and even in the housing. A suggestion is to go to another correction caster system and install OEM busings.

 

[p1michaud]

What with all the stress that the diffs and axle take, any small crack could develop into a pretty serious problem once you are out on the trail and then leave you stranded with a big towing bill.:costumed-smiley-007

Jan,
Very valid point. That's why I've got a replacement (2nd housing now) sitting in the shed. I had picked up a replacement but after a very close inspection found that it was in worse shape than my busted one. The longer term plan is to strip down the front axle and rebuild the other one. Won't dig into that project for a few weeks yet as I've got other priorities at the moment.

This situation is quite common in vehicles who twist the axles very often,but in your particular case, is enhanced by the use of caster correction busings,as i can see in the pictures .Polyurethane is 4 or 5 times harder than rubber and aditionaly the internal pipe of the busing is located very close to the external steel portion leaving almost no place to play, this is good on road but off road generates an excesive tension on the brackets and even in the housing. A suggestion is to go to another correction caster system and install OEM busings.

Very interesting theory. I've been doing lots of thinking about the front axle set up and have asked all my local Toyota experts (three vehicle mechanics, one of them was the shop supervisor for Toyota for 10 years) and none of them have heard of this specific issue on an 80 series front diff. Can you explain what you mean by twisting axles? Do you mean the axle itself or referring to the axle housing due to use of a front locker causing additional twisting/torque on the front housing?

I have replaced the polyurethane bushings with rubber offset ones. Twice the price but better product in my opinion.

Cheers,
P

 

[Sergio Castro F]

Broken Fr. Housing

The FR. axle suspension design makes the axle twist when suspension moves up and down in oppossite ways, for example , when the left tire goes up over an obstacle and the right tire goes down, the entire housing support an effort clockwise in one extreme and counterclokwise in the other.
If you want to see that, do the following, unscrew and put out one of the two bolts of the brackets located under the housing , then put one of the tires over an obstacle and see underside, and let your mind go...
Excuse me for my very basic english, is not my main language

 

[p1michaud]

The FR. axle suspension design makes the axle twist when suspension moves up and down in oppossite ways, for example , when the left tire goes up over an obstacle and the right tire goes down, the entire housing support an effort clockwise in one extreme and counterclokwise in the other.
If you want to see that, do the following, unscrew and put out one of the two bolts of the brackets located under the housing , then put one of the tires over an obstacle and see underside, and let your mind go...
Excuse me for my very basic english, is not my main language

Thanks for the feedback. I'll have a good look when I get the cruiser crossed up over some ruts or obstacles next time. I should have had a look when I was doing this track over at Landcruiser Mountain Park...

No worries with the language, I'm following you.

 

[CanuckMariner/Nomad]

... Excuse me for my very basic english, is not my main language

Sergio, el Inglés es mejor que la mayoría de los miembros de este Foro en español. Lo estás haciendo bien. Aprecio mucho ver a miembros como tú aquí. Gracias por su colaboración. :costumed-smiley-007

Jan,
Very valid point. That's why I've got a replacement (2nd housing now) sitting in the shed. I had picked up a replacement but after a very close inspection found that it was in worse shape than my busted one. The longer term plan is to strip down the front axle and rebuild the other one. Won't dig into that project for a few weeks yet as I've got other priorities at the moment.

Comme vous le savez Pierre, je voyage en solo un peu et pour de longues durées, peut-être vous faire aussi bien. avoir de pièces de rechange est une bonne chose, mais le maintien de votre camion afin qu'il soit prêt parcours est si important. Je suis sûr que vous savez déjà. Nous dépendons tous de nos plates-formes afin muchwhen nous sommes dans une région éloignée de fuite. Dernière chose que nous voulons est de rester coincé là pendant des jours. Tous les meilleurs, Jan :costumed-smiley-007

 

[Box Rocket]

Am I the only that noticed coolant dripping from the bracket in one of the pics? Seems like there is an unrelated coolant leak from somewhere. Could be gear oil, but looks like it could be coolant in the photo

 

[DNTL740]

Sergio, el Inglés es mejor que la mayoría de los miembros de este Foro en español. Lo estás haciendo bien. Aprecio mucho ver a miembros como tú aquí. Gracias por su colaboración. :costumed-smiley-007



Comme vous le savez Pierre, je voyage en solo un peu et pour de longues durées, peut-être vous faire aussi bien. avoir de pièces de rechange est une bonne chose, mais le maintien de votre camion afin qu'il soit prêt parcours est si important. Je suis sûr que vous savez déjà. Nous dépendons tous de nos plates-formes afin muchwhen nous sommes dans une région éloignée de fuite. Dernière chose que nous voulons est de rester coincé là pendant des jours. Tous les meilleurs, Jan :costumed-smiley-007

What a show off!!!:victory: I applaud you for being able to write in more than one language.

 

[CanuckMariner/Nomad]

What a show off!!!:victory: I applaud you for being able to write in more than one language.

Cristian, no showing off at all and thank you!. When you come from Switzerland, one tends to learn a few languages when young. Too bad Americans and Canadians alike do not take advantage of learning more than one language (Spanish/French and others are offered in schools) while they are young. :costumed-smiley-007

 

[DNTL740]

I speak and write English and Spanish, and I took German in High School, unfortunately, it didn't stick!!!

 

[p1michaud]

Am I the only that noticed coolant dripping from the bracket in one of the pics? Seems like there is an unrelated coolant leak from somewhere. Could be gear oil, but looks like it could be coolant in the photo

Very good eye, that was in fact gear oil. The very oil that lead me to find the damaged housing in the first place...:sombrero:

 

[Sergio Castro F]

Broken Fr. Diff. Housing.

I'm happy that you understand the reasons that had make break the brackets.
Sounds strange for me the aussies mechanics does not know about this matter since Australian conditions are very hard.
Here in Venezuela is a quite common problem specially with 78 and 79 series who works in very hard places.
Impressive your picture........see ya mate

 

[Sergio Castro F]

Sergio, el Inglés es mejor que la mayoría de los miembros de este Foro en español. Lo estás haciendo bien. Aprecio mucho ver a miembros como tú aquí. Gracias por su colaboración. :costumed-smiley-007

Thanks a lot, I appreciate your words.