My '99 Super Duty with manual locking front hubs had a pretty big issue today. Driving on highway off ramp, in 2 wheel drive, there was a loud "clunk" and as I slowed it sounded worse and worse to the point as I stopped --- I STOPPED. It did not want to roll forward any more. I could back up (to get out of the way) but that was it. There was a "smoky" steam coming out from under the front axle.

When I got towed home, I could see where the front drive shaft enters the front differential, it was broken out/free from the chuck. There was gear oil spray around the drivers' wheel well.

I'm not an expert here - anyone guess what went wrong? Maybe I had one of the manual locking hubs "locked" and it kept the axle, and therefore driveshaft, spinning and it finally ...ceased and broke out of the chuck?

Not sure what to do next, or what I might do to eliminate hub/axle/drive shaft/transfer case???

Thank you.

Jay

 

How do your front axle u-joints look? I suspect one of them got in a bind and locked up the front ring and pinion. Sometimes those axles will spin even with the hubs not locked

 

I don't know, but, I'll take a look.

 

What is a "chuck"?

 

Hah; good question. I am NOT a strong mechanic so this may have no use in normal mechanical terminology, but, to me: It's the thing that houses the differential. The "rear end" on a rear wheel drive car that has the gears in it. Like a "12-bolt" rear end? That, to me, is the 'chuck'.

What is fugly looking on the front axle on my truck, that has the drive shaft coming into it from the transfer case, as it is Bolted on to the ...chuch/differential/"rear end - in the front", is pryed out, busted out. Still connected but a good inch backed out of that front differential.

If I can upload a picture tonight I will. Thanks/sorry,

Jay

 

Looks like you are in need of some serious front differential work, looks like at least the pinion bearings are out and quite/very possibly more. Until you can get it looked at I would make sure the hubs are unlocked and you are in 2WD. That part you call the chuck is the differential "pumpkin". I am a retired Master Certified auto, light and heavy truck tech and would suggest that as you have stated you are not a "strong" mechanic, I would take it to a driveline shop or at least a dealer. You may find that it would be cheaper to get a junk yard axle,make sure you match the gear ratio, and swap that in. Also just to be safe, not knowing the service history of your truck or the actual reason for the problem also check the fluid level in the transfer case and rear axle to avoid the same kind of problem reacuring. Having one or the other front hub locked did not cause this problem.

 

Probably no oil in there or someone did a pinion seal in the past and didn't tighten properly etc.
Either way its gotta come apart as said above. Check hubs etc.Axles should spin free..

 

Thank you, Jetjockey.

Is there any way to figure out if what is still on the truck can be salvaged; replacing component parts as needed vs. the whole axle and ...pumpkin? I'm not as 'green' as I make it sound; I've done a frame off restoration of a '65 Buick Riviera, pulled the engine & tranny, and done tons of wheel bearings, wheel assemblies, brake calipers, starters, etc.

I'd like to try and dig into this a bit more to save money with the repair shop as I picture that being a $1,000-$1,500 repair bill. If that's the case, even though the truck runs well and only has about 125k miles, I don't expect the truck is worth a whole lot more than $2,500 with everything working as it did previous to this mishap...

Thanks again.

Jay

 

I think the word you were looking for was chunk, not chuck, lol. It's another common term for the differential, or pumpkin. Definitely looks like the pinion bearings came apart, and there's probably some major damage in there, but it's hard to tell for sure without pulling the carrier, or at least the cover to check the ring gear. I would probably just find a used front axle from hub to hub and swap it in. You should be able to handle that from what you say, pretty easy job. Like said already, match your gear ratio.

 

Thanks Ron. I'll start huntin down a new axle setup. Any guestimates on what a reasonable cost might be for one? Feels like a few hundred bucks at a minimum...

 

My local pull a part charge 189 plus 30 core charge if you want to pull it yourself. Prices will vary by company. Sometimes you can get lucky on Craigslist.

 

Thanks Ron. Maybe I'll have to take a run down to TN :-).

 

Rebuild it. you might get lucky and not need too many parts.

 

Depending on what is bad in the front axle having it rebuilt will probably exceed what you think the truck is worth. I have seen used complete front axles go for as little as $100.00 and as much as $1500.00, shop around and have the junk yard pull the cover off the differential and look inside, also check to see if there is any sideways play in the pinion. I believe you have a Dana 50 front end, you can also use a Dana 60, any year from '99 to '04 should work, must be leaf spring axle, '05 and newer are coil spring and won't work.

 

Thank you. Have you seen any good DIY videos or writeups?