I have a 97 F150 XLT ext Cab 5.4L 4X4. I put 3" Lift Add-a-leaf on the rear for added towing capacity. And Keyway-5 torsion keys on the front. The Driver side key is as loose as it will go to keep the screw in contact with the key, the diver side is about an inch further in, had to do this to make it level left to right. All new ball joints, and tie rod ends. My CV boots tore so I put MasterCraft(oreiley's) CV axles on it.
The other day i was t a buddies house and noticed i was leaking gear lube from the front. After inspection the Axle tube right by the flage for the differencial was cracked. I went to the dealer and bought a new axle tube, $225. After getting the differencial off i noticed bearing laying loose everywhere in the differencial and the oil looked like it was half water. So I went to a junk yard and bought a whole differencial with tube and all. It was in extremely good shape, Cost me $225.
Put the new differencial on everything looked good. About a week later, same thing, leaking flid and axle tube cracked same place.
WHAT IS CAUSING THIS??????
I dont want to go through this again. i have to find the cause before i put another differencial on it and break it too.
Please help me out, has anyone seen this before and what causes it?

thank you for any help
Cody

 

those aftermarket keys.....GO BACK to the stock keys....mine cracked with the keys and it was because of the keys...i replace the whole thing a couple of months ago heres a pic

 

But what exactly did the keys change to cause this. I'm sure the keys were the root of it. But they had to change something else that actually caused it. I want to fix the problem not remove the keys.
I have a theory but i'm not sure.
I replaced the CV axels with Oreiley's Master Craft brand. I dont know if they have as much degree of movement in them.
I am thinking that when i go into a fast corner, or hit a big bump and the contol arm drops. Maybe the cv axle is binding before the control arm actually hits the hard stop.
I may look into making a bracket to allow me to drop the differencial a couple inches.
What are your alls opinions?

 

CHANGE BACK TO STOCK KEYS....my opinion.......the aftermarket keys reindexes your suspension and makes harsh angles....my theory is that those angled cv's (one which is connected to the axle tube) binds the internal axle shaft and puts stress on that tube and breaks it...if you made a bracket to drop the diff you would have to make a bracket to drop EVERYTHING...aka a suspension lift

 

Ok so after allot of money and more problems than i want to list. I have new wheel bearings, OEM CV axles and yet another Differencial. With the truck jacked up on stands. The wheels spin freely. They did not do that before. Here is a video of what was happening. I think it was the o'reiley's master pro CV axles that caused all of this. Click on the pic to see video.


For safe measure i returned to my factory torsion keys. But I really dont think it was the problem, part of the cause yes, but not the problem.

Now my problem is brakes. what i have a post under brakes forum.
Also I want to lift the front about 3 inches. The rear of the truck is 3.5" up from stock. And the front it stock. Its looks rediculous.
What is going to be the most cost effective and safe way of doing this?

 

RCX 5 inch lift...$875 shipped....or a 3 inch body lift around $200