My 05 F350 with about 6K miles on it puked about an 1/8 ounce or more of oil out the front differential vent tube onto my driveway. I'm confused as to how this could have happened.Should I take it to the shop or is this just a rare occurrence?

 

A things could have happened:
1) The diff was overfilled and when it got hot, it vented the excess fluid.
2) The ring and pinion are not setup correctly and is overheating thereby venting fluid.
3) The ring and pinion are still not completely broken in in which case it will run hotter than usual until they are.

The interesting thing is that your front diff was engaged. Was it because you were in 4WD mode or you had your manual hubs engaged? In normal 2WD operation (ESOF) the front diff doesn't turn. On MSOF trucks, when the hubs are unlocked, the diff doesn't turn either so no heat buildup or venting should occur. Check the fluid level cold, see if the fluid is even with the check plug. If fluid runs out when you unscrew the plug, then it might have been overfilled. If you were in 2WD mode or with the hubs unlocked, then you should probably take it to the dealer to see why the hubs are staying locked.

 

The differential was a bit over filled. I just pulled the plug and about 3/4 ounce of 40 degree fahrenheit oil came out.
The venting did happen after a 90 mile freeway trip. However, It has been about a month since the truck has been in 4x (ESOF) and the hubs are in the auto position.
BTW, thanks for the quick reply

 

I don't know how the previous poster knows if your front diff was engaged or not--there is no mention of it in your first post. But, just to be sure that your ESOF is working properly, with the truck in park, and the emergency brake set, so you don't get run over, get under the truck and see if you can rotate the u-joints at both ends of the front axle. If you can, everything is OK--if you can't, and they seem locked, then your ESOF is not disengaging. I always push a little extra fluid into both my front and rear axles, and have never had a leak or an overflow condition.

RON

 

I can,with some effort, rotate the right u-joints but the left one will not turn. I don't know if it matters in this case but the front drive shaft can be rotated too.
thanks

 

Well sounds like you have a problem with the left hub,if you can not turn that side axle shaft.
also if this truck was in a flooded area or driven through deep water. Water can find it way in through the vent tube and displace the gear lube.
Not likely though.A slight over fill should not cause this.
Get it back to the dealer.

Rich

 

I think you missed this,

puked about an 1/8 ounce or more of oil out the front differential

 

I guess i'll take it to the shop for some TLC.
thanks guys
Rick

 

You might be able to get that hub out using the manual override. It might do the trick, but things are always a little weird with ESOF.

Turn the hub lock to LOCK from AUTO and drive the truck forward for a few feet. Then get out and turn it back to AUTO. Back up at least 20 feet, then check and see if you got it free. The U-Joints at both front wheels ought to be able to move freely when you aren't in 4x4. Otherwise, parts in the front axle will be turning.

Obviously, the drive shaft going from the transfer case to the front axle should spin freely, too.

 

^ Tried it but the left front hub is still locked.
Curious, since the hub is locked shouldn't the front drive shaft also be locked? My minds eye sees the wheel locked by the hub/axle to the differential which is connected to the front drive shaft. Am I missing a part in between?

 

no the drive shaft will not be locked. the front diff is a open diff. it will send power to the area with least resistance. so in your case the unlocked axle.

 

no an open diff will allow any 2 of the three points to rotate IE both axles, or either axle and the driveshaft, so with one hub locked, and one unlocked you were probably running the spider gears really hard which they really aren't made to do, and since they ride on basically a thrust washer type of setup they will build up heat really bad when they are spinning like that.
I had a hub lock up on my truck and it took busting the hub into pieces to get it out they corrode internally really easy and then lock themselves to the axle, and in my case it hadn't been locked in for about 3 months at all when it did this.