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Rear axle broke
Posted: Sun Nov 12, 2006 10:17 pm
by russ
I'm pretty certain I broke the right rear axle on my 710K. Its behavior is:
Lockers off, 4wd off, it just sits when engaged.
Rear locker on it moves. 4wd on it moves (front wheel drive).
Is it the axle? If not what else might do this (since locker seems to operate fine)? Assuming it's the axle what seals/bearings should be replaced? I'm already going to replace the split boot on that axle with a solid one since it's off anyway.
thanks in advance
Posted: Mon Nov 13, 2006 7:47 am
by kc4mne
Sounds like a busted axle to me.
Pick up rear of truck with rear locker engaged and truck in gear. Whichever tire spins free has a busted axle.
Harbour Freight or Northern Tool 2-Ton Porta Power does a fine job on pulling out the wheel Drive.
Splines
Posted: Mon Nov 13, 2006 10:36 am
by EuroTruck
Russ,
I've seen this happen one other time and it was actually where the splines on the end of the axle shaft had wrung off inside the differential. It happened with a tire spinning out of a gravel driveway onto a paved road when the tire caught traction.
You'll need to see exactly what is broken before reccomendations for replacement parts can be made.
-Sean P.
Posted: Mon Nov 13, 2006 12:20 pm
by russ
Thanks Sean. The truck had the rear locker on when it broke. I drove over a rock and at the time thought the noise I heard was just the rock hitting the truck.
What you said is sound advice. I need to get it to a place where I can tear it down and find out what's really wrong inside.
thanks
Posted: Mon Nov 13, 2006 12:31 pm
by PinzEOD
When mine snapped, the most worrisome part was getting the broken piece of axle out of the inner axle housing/differential. I wasn't looking forward to disassembling the diff. Fortunately, I was able to 'finesses' it out with a bit of a slide hammer technique using a Sears heavy duty pickup magnet. I had a clean break right where the splines began on the axle shaft.
Posted: Mon Nov 13, 2006 2:57 pm
by russ
I guess picking up the truck and shaking the broken end out wouldn't work.
I will have to hope it's on the hub side or somewhere in the middle. I'm really hoping it didn't tear up the spline end on the hub or worse the differential.
thanks.
Posted: Mon Nov 13, 2006 3:01 pm
by David Dunn
russ wrote:I guess picking up the truck and shaking the broken end out wouldn't work.
Wanta use my forklift?

Posted: Mon Nov 13, 2006 3:30 pm
by Jim LaGuardia
A magnet or stiff wire will work to remove the broken parts.
The axles are most likely to break close to the diff end as the diameter is smaller there.
I suggest replacing the stub axle seal in the backing plate while it is apart.
If you don't know what size seal you have(there are 2 types, 55 or 60mm), order a matching seal and spacer.
Also make sure the welsh plug did not get pushed into the diff(check after removing broken piece.
Posted: Mon Nov 13, 2006 5:57 pm
by russ
I can get a forklift. That just might work!
Actually the broken axle is attached to the one hub I haven't replaced a seal on yet. The others were 60mm on the outside wheel drive. I'm assuming wheel side adn stub axle match. No standard things to replace on the diff assuming nothing broke there? For welsh plug will it be obvious how to push back into place? Is that a diff tear down to get to it?
Posted: Mon Nov 13, 2006 10:14 pm
by Jim LaGuardia
Diff assy teardown required to replace the welsh plug if it is pushed in

Posted: Mon Nov 13, 2006 11:41 pm
by russ
OK, I need to do this after Thanksgiving!
Once I've gone that far it won't matter how deep I go. Well, except for the cost of parts...

Posted: Thu Jan 11, 2007 1:50 pm
by russ
Axle broke nice and clean near the differential. The splined end came right out of the differential with a magnet. It was a little tough to get the axle housing separated, had to use a cold chisel to wedge the gap apart a little and then it slid off with some persuasion from a small hydraulic bottle jack.
So, what parts should be replaced besides the axle? My list so far is:
- axle of course
- inner wheel hub seal, either 60 or 55mm, all others have been 60 on mine so far
- O-ring in axle housing? 902.3775, can I get this anywhere, do I even need to worry about if it looks fine?
- split boot with solid one, all I seem to ever see now are split boots
I'm not sure what I should see in the differential to know if the welsh plug is still there. I'm assuming it will block me seeing anything past where the end of the axle shaft went.
I haven't disassembled the hub side yet, probably do that in a bit. Thanks for all the help so far,
russ
Posted: Thu Jan 18, 2007 8:48 pm
by russ
Happiness is a fully operational Pinz. All back together and running nice. Ready for some trails this weekend.
Posted: Fri Jan 19, 2007 5:57 am
by Wayne Roberts
Glad to hear that you have got your truck back together. Scottsmore has been wet on and off but not worth driving accross the state yet. I will keep you posted. Have fun at RR this weekend.
Wayne
Posted: Fri Jan 19, 2007 12:50 pm
by russ
Looking forward to checking out the place soon. Looks like the military vehicle group is on a bad weekend for me so right now I don't think I will get up there, Rene and Rick may go though, might even have a 712 by then.