My brother in law has a 78' Bronco. Three weeks ago he was cut off while driving down the road and slammed on the brakes. He had a heck of a time driving it back home. It would barely go when turning without really flooring it. Upon inspection the e-brake fork was bent and somehow jammed as a result of the quick stop. The e-brake was disabled so he could still drive it. That was just 2 days ago. Yesterday he hopped in to go cut some firewood and had just turned onto the main road. He said it made no noises and seemed to drive without any drag when all of a sudden the right rear axle snapped about 1.5 inches from the hub. The whole tire, wheel, brake drum, hub, and a small stub of axle fell off damaging the right rear quarter and then the truck fell on the end of the axle tube crushing the drum brake shoes and dumped gear oil all over the road. He said it has a locker but I don't know much about them and if it does it is automatic instead of manual because there are no manual controls to engage/disengage it.

Here are my quesions:

What could have caused this to happen?

How do we know if the locker is bad?

If we pull the axle out of the opposite side to count the splines (should be 31 from what the previous owner said) how do we get the broken shaft out of the tube?

What should be checked before slapping another axle in so we are sure it won't happen again?

Currently it's up on blocks and nothing has been taken apart yet. I have a mechanical background just not on this specific issue. I was hoping the shaft could be pushed out from the other side but only someone who has had a nine inch rear end apart would know that answer. The Bronco has a 4 or 6 inch lift and is running 35's. The motor is the 460.

 

You gotta fully dissasemble the rear end and then mabey you can use something to push the rest of the axle out through. is that what your asking to do? and sounds like he has bad luck.

 

If what I read is true about this particular rear end the axles do not use C-clips to hold them in so I can remove the 4 bolt flange on the other side to remove the shaft but I will need to get the broken shaft out of the ring and pinion assembly before I can remove the third member. The shaft is inside the tube a couple inches and I'm not sure if I can drill and tap the shaft to get something to pull on. I think we are going to try and remove the axle from the left side and see what that will allow us to do.

 

I know to remove the other axle you need to remove the drive shaft. undo the bolt in the middle of the shaft that the drive shaft u joints connect up to then after you pull all that crap out. you have to unbolt the first set of bolts then remove all that stuff. then you can finaly remove the second set of bolts and then from there you can acctualy get the axles out...

 

If this is a true 9" all that holds the axle in is a set of four bolts that are behind the axle flange ( the part of the axle that the brake drum is attached to ) that are fit tru a flanged retainer that holds the bearing and the axle. Pull the wheel off, remove the brake drum ,remove the bolts and attache a slid hammer and bump it out.......But you can't pull the opposite axle from your broken one and put something in to push the broken one out because the spider gears and /or locker are in the middle of the carrier blocking you . You may get lucky as I did. The axle was broken right at the bearing and I was able to get a pair of needle nose vise grips in and get a hold of the axle and wiggle it out.
Good Luck!
Kenny
Ohh.....big mud tires will do this to your axles...don't ask how I know

 

Well we sort of got lucky. The broken axle shaft was recessed only a couple inches in the tube. We removed the brake assembly plate that came loose with the four flange bolts and were able to use 2 screwdrivers to pull the broken shaft out. The bearing was cracked and we has to take out the inner race along with the roller bearings. Now we need to remove the outer race and then get a new axle with bearing and seal. Some gear oil and a replacement brake shoe kit and we should be good to go.

 

Good Deal !!! I hope you can get it fixed and going without any more problems .
Kenny

 

A 460, a 6000 lb truck, 35" tires and a stock 9" just aren't going to play well together. If this were my truck I would want to get some stronger shafts so this doesn't happen again. Next time the results could be a lot worse. Can you imagine if the wheel had fallen off doing 65 on the freeway?

I would just pull the third member and visually inspect it for problems and see if everything moves OK. If it's broken it should be obvious.

 

I would pull the center unit out and inspect it . It would be easy because half the work is already done . Just pull the the other axle and the drive shaft .
I have see the roller bearing at the end of the pinion break the casting it sits in . Then the broken cast piece gets logged between the ring and pinion locking them up. This causing the axle to sheer off at the wheel end because the tire keeps turning the axle that can't move.

 

I had the same thing happen to me last year on the freeway pulling a trailer. Scary. I have to wonder if I might have had a wheel bearing going bad and getting hot. I don't know but the truck hasn't been the same since. I would really recommend spending the money on quality wheel bearings especially with bigger tires.