I had front diff leak (pinion seal) not dripping but the area was wet. after a recent 550 mile trip, I now have pretty bad leak, where the front drive shaft goes into the transfer case. I think this is called the transfer case output shaft, please correct me if I am wrong, because I need to order the seal. I don't know if the area start leaking because of the hesitations and jerking at high way speed due to a probable sticky Idle Air Control Valve, since the area was completely dry before the trip. When I was looking at the front seal, I found the seal alone and also a flange set, much more expensive which also includes the seal. The bolts that attaches the flange to front drive shaft and also the transfer case seems to be nylock. And if I understand correctly they need to be replaced each times they are unbolted. My questions are:
1. Do I need the flange set/ or new nylock bolts or I could reuse everything and just changed the seals.
2. Any body knows, what size bolts they are?

3. Is it true that I have to mark the location of the big bolt holding the flange and count how many turns it needs to come off and tighten it back to the same location?

Since the drive shaft will be completely off, I am planning on rebuilding it. a local drive line shop will change the u-joints for me.

 

You dont need to replace that nylock nut. Find the torque spec in the RAVE for the correct tightness. If I remember correctly its around 150 ft lbs/175 ft lbs. You may need to rent a torque wrench for free from a local auto parts store.
You just need a new seal. Its tuff to remove, so you need a good heavy duty pick set to get at it from the side.
It may be a good practice to mark the location of the drive shaft. So you put it in the same position on the flange. But most importantly is they your drive line shop balances it properly.

 

always replace nylock nuts, they a designed to be use one time.

 

And, you may need a new front flange cause if they are allowed to move much the can wear a grove and a seal will not fix the issue.

 

The propshaft / driveshaft nylock nuts are Grade 5, 3/8", 24 TPI. Nylon locking nuts cannot be reused in any application. You can't find them at the big chain stores, you'll have to go to the local hardware store (ACE) to find them. When buying individual unmarked bolts and nuts, its good practice to buy a few extra, in case they got mixed up in the bin by a previous customer and you get a few of the wrong size.

 

Thanks for the info on bolt sizes and where to get them