front diff went bang

[cptmud]

Took off from a set of lights today, big bang from the front end, and a grinding sound, no drive. after a few swear words, engaged the centre diff lock, no noise and drive. limped the truck home, pulled the front drive shaft out, and the pinnon drive spins freely with both wheels on the ground. Any ideas on whats let go, and where to start looking

 

[topend yobbo]

As the heading says , maybe the front diff?

 

[KLF]

Doesn't really matter, you gotta take it apart anyway.

Very curious to know what happened, though. Post pics!

 

[upcruiser]

This is exactly what happened to my rig a year ago. Turned out to be the gears and the splines of the inner axles had a disagreement. Lots of metal shavings ensued. You'll have to pull everything apart anyway, but if you want a quicker answer, pull the diff drain plug and look for metal shavings, that'll be a fast way to confirm this.

 

[Rainy Day FZJ]

Could be the drive flanges at the end of the axle. Easiest and probably cheapest. Do you feel grinding at the pinion when you turn it? Pull off the end caps at the drive flanges and have someone watch to see if one of the axles turn. good luck..

 

[Newps]

My guess is the ring and pinion gears are toast. Not a good idea to drive a rig when you have a major mechanical failure. You could have caused some major damage if you have a locker. Next time you might want to call a flat bed if you cannot make a roadside repair.

 

[IdahoDoug]

Knowing what model, year, miles, front axle maintenance status, etc would be handy....

Sorry to hear about it - doesn't sound cheap/simple.

DougM

 

[topend yobbo]

Come on , whats the verdict?

 

[cptmud]

ended up being a cheap and easy repair. Finally got some time to pull the front end apart, no fillings in the diff fluid, pulled the cvs, no they where fine, put the cvs back in , everything seem to turn and be alright. Very confused i started putting everything back togather, when i noticed the teeth on the flange on the drivers side had all sheared off. dont know how it happened, but a new flange has solved the problem. will post a pic of the problem part when i download the pics.

 

[Cruiserdrew]

Not an uncommon problem. I replaced the drive flanges last year at 90k miles and it improved the small klunk I had in the driveline. I think they are built to wear at a predictable rate and are not as hard as the splines on the birfields.