FJ80 Axle Housing Strength?

[Mud Nut]

Hi guys,

I'm new here and I'm told this is the place to talk about FJ80 axles!? I'd like to get some tech stuff going on... I searched, but couldn't find much.

I'm basically wondering on the FJ80 front axle housing strength. I'm talking about the actual housings, not things like ring gears, axle shafts, hubs, and so on... How do these housings normally fail? Do the axle tubes bend? If anyone has pictures, that would be great also. In what direction do they bend?

I'm assuming the appeal of the Diamond housing has to do with the extra thickness of the axle tubes? With that said, what's the difference in weight between a stock FJ80 front axle housing, and a Diamond front housing setup the same way?

Any information will be helpful on this topic. Thanks guys!

 

[TheBigBoy]

http://www.superiorengineering.com....=4407&osCsid=0c68550ff3608d15109cdeb10c07aae4

 

[Mud Nut]

Thanks for the link, I appreciate it.

Anyone have any housing failures?

 

[Kernal]

Not the expert but there have been some threads on the subject; you could do an advanced search for axle+housing+bent (use the + sign to tie your search words together) in the 80 forum and read through a few. Here's one:

https://forum.ih8mud.com/80-series-tech/547429-front-axle-housing-how-determine-if-bent.html

 

[inkpot]

Thanks for the link, I appreciate it.

Anyone have any housing failures?

Local guy in our club did manage to bend his front axle housing by doing a Mega Jump in the dunes. He is an ex bike racer and got a wee bit carried away. We have several other members who wheel the snot out of their 80's and have never had any problems with it. The front diff cover is a soft spot, easy to ding up in the rocks. Some if the interest in aftermarket axle housings may be due to them having a bigger ring and pinion set available. John

 

[Wrench]

http://www.superiorengineering.com....=4407&osCsid=0c68550ff3608d15109cdeb10c07aae4

That is dumb. Why would you want to give up ground clearance. I certainly would not! The axle is already braced from the factory. Look at other axles they don't have the same bracing.

 

[TheBigBoy]

That is dumb. Why would you want to give up ground clearance. I certainly would not! The axle is already braced from the factory. Look at other axles they don't have the same bracing.

What ever.

Show me where it's braced from factory? Show me where they bend (and they do bend very often). 1 out of every 4 housings I get is bent. You can put the truss ontop of the housing you know.

 

[inkpot]

That is dumb. Why would you want to give up ground clearance. I certainly would not! The axle is already braced from the factory. Look at other axles they don't have the same bracing.

At some point you have to decide how hard your going to beat your rig. Then look around and see if others that are running that hard are having issues with axle strength. Compared to the 40/55/60/62 axles, the 80 is much stronger. It is not perfect, as it can be damaged if you beat it hard enough. I don't plan on jumping my rig, and when I am in the rocks I try to drive gracefully enough that I don't risk damage to anything. With the rig locked, lifted, armored, and driven with the 2-pedal technique, it is just amazing how easy it is to do some serious krawlin. John

 

[LINUS]

I bent my FR axle shell in a spot where I know I did do it, but I've done way worse in my '68 International Travelall (like an old Suburban) with factory 3/4 ton running gear without any issues.

I asked Christo when I was hunting for a used shell & he said it wasn't an uncommon thing to happen - so since I was going to go to e-lockers, it made replacing it with a new one w/ a e-lock flange in it a no-brainer.

Strangely enough, my shell bend was all on the short side (Passenger in USA rigs) - so those braces / welding any sort of brace for the long side wouldn't have done me any good - I bent mine about 7/16" in the narrow area & it bent all the way into the 3rd member flange (was leaking diff fluid, 1st sign I had more than just alignment issues on the asphalt drive home that day) - it was enough to chew up the splines on the inner driveshaft & crack the drive cuff /socket in the 3rd, and send some metal shards into the diff fluid.

So yeah - it's been told to me that the housing is the weak point, all the rest is stout, so if you are really worried about it, then maybe brace it, but don't think a longside brace will make it bulletproof.

I'd sooner weld some plate on the bottom of the diff area to keep rock rub from killing the drainplug, that little ring from the factory is a nice thought & worked for 99% of the buyers of these when they were new, but now with us loonies doing God only know what in them, that little ring just begs to get soundly smashed flat.

 

[IdahoDoug]

My brother in law's rear axle housing is bent from being backed into a stump that hit the driver's side tire at about 20mph and stopped the entire truck. It slowly wears a gentle pattern in the rear tires from being slightly toe in. One day when he wears out something fatal on the truck (now at 360k) it will be mine and I'll have it straightened and while that's being done I'll slam a crate V8 in it and make it a trail queen.

The front axle housing is plenty strong for stock tire sizes and hard wheeling. But as soon as your vehicle leaves the ground you are about to generate forces upon landing that are simply beyond sense to design stock components for.

DougM

DougM

 

[motormayhem]

I bent my FR axle shell in a spot where I know I did do it, but I've done way worse in my '68 International Travelall (like an old Suburban) with factory 3/4 ton running gear without any issues.

I asked Christo when I was hunting for a used shell & he said it wasn't an uncommon thing to happen - so since I was going to go to e-lockers, it made replacing it with a new one w/ a e-lock flange in it a no-brainer.

Strangely enough, my shell bend was all on the short side (Passenger in USA rigs) - so those braces / welding any sort of brace for the long side wouldn't have done me any good - I bent mine about 7/16" in the narrow area & it bent all the way into the 3rd member flange (was leaking diff fluid, 1st sign I had more than just alignment issues on the asphalt drive home that day) - it was enough to chew up the splines on the inner driveshaft & crack the drive cuff /socket in the 3rd, and send some metal shards into the diff fluid.

So yeah - it's been told to me that the housing is the weak point, all the rest is stout, so if you are really worried about it, then maybe brace it, but don't think a longside brace will make it bulletproof.

I'd sooner weld some plate on the bottom of the diff area to keep rock rub from killing the drainplug, that little ring from the factory is a nice thought & worked for 99% of the buyers of these when they were new, but now with us loonies doing God only know what in them, that little ring just begs to get soundly smashed flat.

Hey @LINUS looks like you are still active on the forums so I’ll dig up this old thread to ask. When you bent the pass side of your housing which way did you rig pull? Trying to track down a pull to the right on my rig.