D20 Seals

Contributed By: Ken Wetherall

So i got the 20 off, i can actually bench press this thing on and off. :) laid it on the work bench and afixed 1 of the mounting ears in a vice to hold the case steady on the bench but not with any REAL weight on it. i couldnt get a normal seal puller to work on the output shaft seals so i just chiseled em out. did no damage to the holes they r in :) but the prob is that, how do u get the nu 1s in properly? i used some real generic seals i had and bent the crap out of the metal face that supports the rubber seal, so badly that it wouldnt seal on the yoke properly. hmmm, the construction of the cheap seals makes em flimsy. i went to the store and got some National seals. man, these babys are BUILT! lot more robust, and have an additional support plate BEHIND the rubber seal to reduce crushing during installation. now the OEM has a special tool to install, but none r around when u need 1. a normal seal installer that u might use on say the grease seals on the front hubs or the seal in the front cover would not work cuz u got the ends of the outputshafts protruding from the case. so off the the hardware supply store i go. great place for inovation/inspiration/persperation. i measure the ID of the hole in the case where the seal lives and that is 2.5". i go into the plumbing dept and find what is termed a 'bell reducer' it was sized 1.5x1/2" big end 1.5" pipe thread and the small end 1/2 pipe thread. i measured its OD and it was a hair under 2.5", cool. but i would need to hammer on its small end to use it effectively. so i found me a pipe plug for the small end of the reducer. total cost, 6$. i got them home, got a HD cutting board from the kitchen, some wet/dry 320 sandpaper and sanded flat the surface that would come into contact with the seal as best i could. i had looked at a couple of the reducers in the store in order to find 1 that had the least amount of casting flash. but then i found out that the OD was not round and so i had to use the grinder to reduce the hi spots. but man, when i first use that thing IT IS GREAT. the outside of the seal was not deformed in any way. just perfect. im takiing this little construction item in me jeep in case i have to replace a OP shaft seal in the field also, i had noticed excessive play in the front OP yoke. the d20 has adjusting shims at the rear of the case opposite of the yoke to compensate. i removed the thinnest shim and felt much less play than b4. i also removed the front yoke, of corse, and reinstalled it in the rear and installed in front, the yoke for my CV joint. so tomorrow ill fashion a gasket from cork, and reinstall the unit.

Ken Wetherall
Concord, CA.