Posted by Clint Dixon (Curator of Antiquities) on Tuesday, March 14, 2006 at 9:59PM :
In Reply to: Transfer case seal leaks? posted by John S on Tuesday, March 14, 2006 at 7:13PM :
Hi John. I received your email on the subject. I decided to answer you questions here in hopes of helping others in the process.
I don't know if you have seen it yet, but below, you will find a link to a list of replacement National Oil Seals that I compiled for the WDX-WM300 POWER-WAGON. The information came directly from the source of manuals listed at the end of the lists. The seals are shown in three lists: 1) Available leather seals 2) direct cross reference, Chrysler number to National number 3) conversion by number size and type.
As you remember, last year at about this time, I was contemplating replacing leaking seals in my transfer case…for the third time. I ended up trying a narrower seal that I had not included on my list. It was not included on my list because when I compiled it I was trying to stay with seals as close as possible to the width and construction of the originals. The seals I used this time around fit the same shaft and bore size, but are only .375 wide compared to the original Chryslers at over.500 in width. With these narrow seals, I was able to stack two front-to-back in each housing bore. They are double lip seals, so I now have four sealing surfaces per companion yoke. The seals I used are National number 473468. The lip material is Nitrile. I believe seals with a lip material of Polyacrylate may last longer in the high operating temperatures found in the POWER-WAGON transfer case. Polyacrylate is not available in all seal types, sizes, or lip construction. It is also higher priced and may not be readily available in small quantities.
I have run these seals in the transfer case for almost a year now. I still get some leakage past the sealing surfaces, but it is not a constant leak like before and it does not end up covering all surfaces on the underside of the truck from transfer case rearward like previously. I used new wear sleeves on the sealing surfaces of the companion yokes. For lubricant in the transfer case I use Mystic JT-7 Multi Purpose Gear Lubricant, SAE 85W-140, API GL-2 thru GL-6 + LS. 140W is the recommended viscosity as shown in my W-Series Approved Lubrication service department poster for temperatures above +32 degrees F. for the Transfer Case and Transmission found on the WDX.
After one year I am happy with the results and can live with some seepage.
Junior