Front differential oil leak at pinion seal

[MCMOND]

Greetings from North Carolina! My front differential has a minor leak where the front prop shaft meets the front differential. There appears to be a flange of some sort that covers the opening to the diff that is loose. This is where the oil is weeping out. Attached are some pictures.
Not sure if it’s related but occasionally in 4th gear and around 60km/h-80km/h the vehicle will shudder or vibrate while trying to accelerate, usually when under load or going up a hill. Could this be related? Thanks in advance for the help.

[BEARMAN]

G'day MCmond. That flange is a mudshield to protect the seal. If it is only the shield that is loose and not the flange that the driveshaft is bolted to it is easy enough to fix. The vibration you speak of could mean the pinion nut has come loose. Can you move the driveshaft up and down where it is bolted to the flange. If there is movement there unbolt the driveshaft and check the tightness of the pinion nut underneath. If it is loose, tightening it up will most likely fix the leak as well.

[MCMOND]

Thank you Bearman!!!
There is no movement that I tell. Do you think it’s still worth checking the pinion nut? Also will doing that tighten the mud shield. I apologize for all the questions but I’m a novice mechanic.
The prop shafts were in bad need of grease so I just did that.
Is unbolting the drive shaft as simple as removing the 4 lock nuts or is there anything more to it? I’ve given some thought to checking the lock nuts on the end of the output shaft and just wondering if it’s as easy as it seems. I’ve read some of the posts where you have stressed how they are to be torqued to around 125ft lbs and Loctite 242. Not sure if the vibration is coming from the transfer case or not. It’s very intermittent. Thanks again.

[BEARMAN]

The mudshield is a press fit on a lip on the drive flange. It may have just come loose. Removing the driveshaft is pretty easy. Just undo those 4 bolts with the nyloc nuts on each end of the shaft. Then you can check the nut that holds the pinion flange - it should have a split pin in a castle nut so really shouldn't come loose unless bearings have worn or the split pin has broken/fallen out. If everything looks/feels good there you might just need a new seal. I would be checking the splines on the driveshaft slip joint for wear also. None of those bolts need to be tensioned to that figure. I think the figure you are mentioning is for the intermediate shaft bolt in the transfer case. Even the nuts on the transfer case output shafts only need to be around 60. Good luck with locating the vibration. There are many places it can come from but start with the drive shaft unis/slip joint, phasing, panhard rod bushes, radius rod bushes, wheel bearings out of adjustment, and swivel preload.

[MCMOND]

Thanks again Bearman.

[MCMOND]

checked most all of the recommended items, everything looked good as far as i could tell. do you think removing the prop shafts and checking the nut on either end of the intermediate shaft bolt from transfer case is a good idea and if so is it as easy as removing the four nuts on either shaft to remove and checking the torque on the nut? is the torque figure for those 125ft/lbs?

I've read several posts that recommend checking the torque and Loctite of certain bolts/nuts regarding transfer case as cheap and easy insurance against failure. Im not sure which ones are being referred to. Are the nuts on either end of the intermediate shaft the only ones or are there more? Any chance those items to check and location can be expanded upon? Thanks again for any help, as you can probably imagine getting parts for the Perentie in the US would be tough so I'm trying to be thorough.

[BEARMAN]

checked most all of the recommended items, everything looked good as far as i could tell. do you think removing the prop shafts and checking the nut on either end of the intermediate shaft bolt from transfer case is a good idea and if so is it as easy as removing the four nuts on either shaft to remove and checking the torque on the nut? is the torque figure for those 125ft/lbs?

I've read several posts that recommend checking the torque and Loctite of certain bolts/nuts regarding transfer case as cheap and easy insurance against failure. Im not sure which ones are being referred to. Are the nuts on either end of the intermediate shaft the only ones or are there more? Any chance those items to check and location can be expanded upon? Thanks again for any help, as you can probably imagine getting parts for the Perentie in the US would be tough so I'm trying to be thorough.

The intermediate shaft is the one between the mainshaft and the centre diff in the transfer case. The 30mm bolt with the lock tab that goes through the shaft is the one that should be torqued to 125ft/lb. The front and rear output shafts that come out of the transfer case are the ones I think you are talking about. These only need to be around 60 ft/lb and they are nyloc locknuts. It is unlikely these would be loose but you may as well do a check - yes just undo the 4 bolts on each end. I think the bolts you are referring to that need loctiting are the ones that hold the low gear on the centre diff and the ones that hold the 2 halves of the centre diff together. To get to this you have to remove the centre diff from the transfer case and do it on the bench. These also only need to be loctited and torqued to  50ft/lb. The parts are still available if you know the parts numbers. Have you got this link https://afmsafety.com.au/database/#LR4X4CARGO

[Chazza]

Have you checked and cleaned the axle case breather? If it is blocked the seals will leak,

Cheers Charlie

[STDDIVER]

I had a similar problem - front drive shaft out of phase as Brian said - smooth as cream now!  Good luck

STDDIVER

[303Gunner]

..I would be checking the splines on the driveshaft slip joint for wear also....... Good luck with locating the vibration. There are many places it can come from but start with the drive shaft unis/slip joint, phasing, panhard rod bushes, radius rod bushes, wheel bearings out of adjustment, and swivel preload.

I had a similar problem - front drive shaft out of phase as Brian said - smooth as cream now!

Note that the front driveshaft Unis ARE SUPPOSED to be out of phase because the transfer case flange and differential flange are not parallel. Putting them in phase will create vibrations. See: This thread

[MCMOND]

Thank you everyone for the great suggestions and thanks Bearman for the detailed explanation and link. I’ll get to work on it soon. I’ve driven it a few times since the prop shafts were serviced with grease and it hasn’t shuddered or vibrated again so maybe that was it but I’ll be checking these other items to be sure. Again thank you!