Help ID Leak (and recommend fix)

[GB26JJ]

New to the forum…and new to big trucks in general!  I recently bought a 2006 Mack CV713 and am running a solo dump business right now. I’ve noticed a leak where the drive shaft connects, just in front of the front tandem wheels (not really in the know as to the parts, sorry).  
 

My dealership has proven WAY less than helpful on other issues so far, so I’m trying to diagnose this issue on my own.  Is this common?  An “easy” fix?

 

Thanks in advance for any help. 

[PD84]

I would first check that yoke and make sure it’s tight.

Ours need retightened about once a year

[Joey Mack]

ok....  push up on the drive shaft, if it moves, locate the movement,  loose yoke bolt is possible.  pull the yoke and then the seal cover....   inspect the yoke for a groove around where the seal rides..  if it has a groove, buy a yoke, speedy sleeves are hit or miss.. replace the seal, and the gasket behind the cover.  get a new yoke bolt,  3AX1803,, and torque to 500 lbft...  install a new u-joint strap kit...  they are cheap,,, around $10 buck's..  top off the oil, and you should be done with this issue...   stay in touch..  jojo

[Onyx610]

You may need a yoke puller, I have on most. Although I’m in the NE. 

[Joey Mack]

i made one out of a 1/4 fender mounting bar..  I burnt a hole in the middle for 5/8" threaded rod,  I had a few cut offs from brake chambers to use as the jack screw and didnt care if it got messed up...  i use the old u-joint straps to hold the bar in place...  and then,,,,  'git'r done'....   a, 3lb hammer does help to get it to break loose..  just like Onyx said...  I know all to well about the rust up north..  My oxy/acet. bill down here is very low....     jojo

[GB26JJ]

I appreciate y’all.

Where do I check this oil level (and add more if necessary)?  No way for me to know how long it’s been leaking, although one of the things the “stealership” did in early July was replace some other U-joints.  I’m assuming they would’ve checked the fluids then, too?

[Joey Mack]

assume only that blinders were worn when the work was done..   On the back of the rear end housing is a 5/8" square plug...  that is where you check and fill the level........         When the carrier is replaced,  you fill the power divider first, (Front rear only) then the side cover (top reduction) then the 'bowl'  rear plug... fill til they spill..  the rear rear has only 2 fill spots...  the side cover first then the rear plug....     jojo

[GB26JJ]

I checked today, and all of the bolts were tight (as far as I could tell).  When I pushed up on the drive shaft, there was a SMALL amount of movement -- just enough for me to be able to "knock" it.  

[Joey Mack]

zero movement on a Mack rear end yoke..   jojo