The output shaft seal on the LJ20 tranny is 28x42x22, and is no longer available, as many of you know. While rebuilding a transmission for my stepdad, I took some measurements, and the 42mm is the INNER diameter of the ring, not the outside diameter. Thus, you can remove your old seal, cut the end with the lip off, and press a 28x42x__ seal into the remaining "ring". I used NAPA seal #10922, which is 28x42x9 I believe, pressed it in, and then pressed the assembly onto the back of the tranny. I have another to do, and will take some pictures when I do it.
So don't throw out those old output shaft seals!
LJ20 Transmission Output Seal
Moderator: stevec
LJ20 Transmission Output Seal
The only difference between an ordeal and an adventure is your attitude
Re: LJ20 Transmission Output Seal
That's great news! I was just about to start designing an adapter to use a normal seal there. I didn't know that you could use your old seal as the adapter. How does the old seal come off the tailhousing? I've been afraid to pry on mine because it might ruin the seal.stevec wrote:The output shaft seal on the LJ20 tranny is 28x42x22, and is no longer available, as many of you know. While rebuilding a transmission for my stepdad, I took some measurements, and the 42mm is the INNER diameter of the ring, not the outside diameter. Thus, you can remove your old seal, cut the end with the lip off, and press a 28x42x__ seal into the remaining "ring". I used NAPA seal #10922, which is 28x42x9 I believe, pressed it in, and then pressed the assembly onto the back of the tranny. I have another to do, and will take some pictures when I do it.
So don't throw out those old output shaft seals!
Thanks,
Tom
Re: LJ20 Transmission Output Seal
It's actually pretty thick metal, so it would take some effort to damage it that bad. I started by wedging a chisel between the bottom of the seal and housing and tapping on it, working my way around. Once you get it started, it gets easier.
I cut mine down as little as possible - just enough to get the old seal off. That allowed me to press the remaining ring all the way down, and still have enough room to hold the seal.
I cut mine down as little as possible - just enough to get the old seal off. That allowed me to press the remaining ring all the way down, and still have enough room to hold the seal.
The only difference between an ordeal and an adventure is your attitude
Re: LJ20 Transmission Output Seal
Using the old parts tranny to experiment on, I removed the outer metal cup. It came off pretty easy, CLEAN and with no damage BUT all the rubber part stayed on the tranny. I used razor knife to cut some rubber off but not having much luck with getting seal off. I am going back to shop with camera and will send you pic of what I have. If you go home in the meantime and have the time, would appreciate lookiing this evening.
Larry
Larry
"LJsRME"
Re: LJ20 Transmission Output Seal
The outer metal cup is not connected to the seal itself. With Stephen’s tranny I had the case apart already, so I put the rear case in a vice to hold it, and gently tapped all the way around it with a chisel. After a few times around, I had a little gap, and was able to use a little more force. The looser it got, the easier it went, and by the time it was half off I was able to twist it off the rest of the way by hand. Probably took 10-15 minutes to get it off, mostly trying to get it started; it was in no way a quick job!
The only difference between an ordeal and an adventure is your attitude
Re: LJ20 Transmission Output Seal
Thanks for the help Steve. For some reason I was stuck on the idea that the metal cup (dust cover, rock protector. or etc.) was part of the seal itself when just a quick look inside would have told me different. After getting you information last night, I went back to the shop and the actual seal on the old parts tranny came off about as easy/difficult as you described. The main problem being that the old parts engine/tranny combo is stored on top of a 8' cabinet and I was working standing on a 6' ladder.
Now I have to figure out how to get both the cup and seal off of Miss Alice without damaging them and with the tranny still installed. Being an old large person with big belly and poor eyesight is not good, either working from a ladder or on my back working up in the LJ20 tunnel. Only the reward of driving a LJ and going to a meet makes it worth while.
Thanks again,
Now I have to figure out how to get both the cup and seal off of Miss Alice without damaging them and with the tranny still installed. Being an old large person with big belly and poor eyesight is not good, either working from a ladder or on my back working up in the LJ20 tunnel. Only the reward of driving a LJ and going to a meet makes it worth while.
Thanks again,
"LJsRME"
Re: LJ20 Transmission Output Seal
Replacing LJ20 tranny output seal with tranny in vehicle. Per stevec's discovery quoted below:
Will post pics of the tools when I get time to do a "how to"
Thanks to stevec for discovering this. Here is some additional information on the subject. Today I made two tools which enabled me to remove both the cup that covers the output shaft seal and the output shaft seal itself WITH the tranny still in the vehicle. The metal ring from the old seal was reused. uncut and with the new seal stevec recommended being pressed in place against the flange of the metal ring just like the original. Spent some time on the tools but I have two more LJs with leaking output shaft seals so will put them to good use.stevec wrote:The output shaft seal on the LJ20 tranny is 28x42x22, and is no longer available, as many of you know. While rebuilding a transmission for my stepdad, I took some measurements, and the 42mm is the INNER diameter of the ring, not the outside diameter. Thus, you can remove your old seal, cut the end with the lip off, and press a 28x42x__ seal into the remaining "ring". I used NAPA seal #10922, which is 28x42x9 I believe, pressed it in, and then pressed the assembly onto the back of the tranny. I have another to do, and will take some pictures when I do it.
So don't throw out those old output shaft seals!
Will post pics of the tools when I get time to do a "how to"
"LJsRME"