Alright, this is getting slightly annoying.. First I blow a trans cooler line and nearly run the transmission dry Sunday.. Now I have brake issues (see thread) and then I park my truck for 5 hours and come back to see the differential is dumping fluid on the driveway.

Why would the differential all of a sudden just START leaking? Nothing has changed... (I did pull the axle shafts to have u joints replaced a while back, but other than that I haven't messed with it..

So I'm thinking now would be a good time to service probably the front and rear differential. Do I use the fill plug that is halfway up the differential to fill and just unbolt and slide the cover off to drain?
Also, just use RTV silicone to seal the differential, correct? I assume there is no gasket?

What are the differential capacities and what weight do I need to use?
I'm at 187k now so assuming its never been done, I might as well do it.

Thanks

 

Bobcat:

When you pulled the front axle shafts to do your u-joints, one of two things, or both, may have happened:

1. you damaged the seals by not supporting the axle level when you pulled them, or let them hang unsupported when pulling.
2. you overfilled the housing. The correct level is 3/4 inch below the fill hole.

Check your fluid level first. If it is overfull, get it back down to the correct level and then give it a couple of weeks to drain any excess out of the axle tubes.

As to type of fluid, I use 90 weight Mobile 1 synthetic.

Capacity: Front Axle 7.6 pts. (Dana 60)
Rear Axle 7.8 pts. (Dana 70 4X4)
Rear Axle 10.1 pts. (Dana 80 4X4)

Blue RTV will work for the sealant, there is no gasket.

John (DH)

 

I have never touched the fluid level of the housing..

And the differential is leaking (or appears to be) leaking out the bottom of the differential.

 

You are speaking of the rear differential?

John (DH)

 

Nope, front differential.

 

Bobcat:

If it is leaking from the end of the axles then either the fluid level is too high or you damaged the seals. Get the fluid level 3/4 " below the fill hole and give it a couple of weeks to drain the excess out of the axle tube. If it still continues to leak from the end of the axle tube then you probably damaged the seals.

If the leak is coming from the pumpkin about the only thing I can guess is the drive shaft seal. Hope you git her done.

John (DH)

 

It is a front driveshaft seal. How hard is that to tackle?

Thanks!

 

Don't really know since I have not done one. Maybe Infidel or JBody will chime in. My rear driveshaft seal started leaking at about 90K. When we took the driveshaft off to get to the seal the yoke had a lot of play - both sideways and in and out so we put the driveshaft on an took her to the shop. Turned out to be the ring and pinion gear was ate up causing the play in the yoke. Be sure to check this out when you remove the drive shaft before going after the seal. Good luck.

John (DH)

 

Hmm.. Thanks for your help John.

Hopefully I can get that seal replaced without having to fix the ring & pinion..

Can someone please post a method to change my front driveshaft seal?

Thanks!