4 Speed Main Drive Seal and Sprocket

[JW113]

Couple questions, I should know this but don't and the FM is of no help.

Main drive seal: FM says press it in flush with the case. However if I do that, which did, the outer lip is not quite on the flat surface of the spacer, and is riding through the groove where the spacer key sits. That can't be good, can it? In fact I'm in there right now trying to fix a trans leak right at that seal. Maybe press it in until it clears the spacer key groove?
[attach=0]

Next question, also not answered by the FM. The trans sprocket is dished. Which way does the dish go? Toward the trans, or toward the clutch? I've been putting it dish towards clutch, but I kinda remember somebody saying it goes towards trans. If it were important, would be nice if they would have said something in the FM.
[attach=1]

thanks,
JW

[Ohio HD]

I would press the seal on until the lip clears any obstruction, grove, etc.

Sprocket, flat side out.


[attach=0,msg1305031]

[JW113]

Thanks Ohio! I thought I had heard that somewhere, here in fact but could not remember. And thanks for including the FM page. After looking at it, I took a look at my old 70-78 FM, and sure enough, there it was. I've gotten into a habit of looking at a 78-84 FM, which in general tends to be written a lot better than the earlier manuals, and no mention of this at all. It even has a section for the transmission sprocket! But they forgot the part about flat side outboard. But now I know, and now will remember. Flat side outboard!

thanks,
JW

[attach=0,msg1305048]

[Ohio HD]

 

I "thought" flat side, but I had to look. It's a long time since I worked on a 4 speed with chain drive.

[JW113]

Man I totally forgot how much I hate replacing the main drive gear seal. I pulled the old one out, went to push the new one in, and saw that the inner seal lip turned inside out on the gear spacer. And realized that the last time I replaced this seal, it did the same thing. Damn, getting old is a bitch.

I picked up a new seal, and this time wrapped the mainshaft with tap so there was not a harsh step where the seat lip passes over the gear spacer. All went sort of OK, but after the last tap on the seal to get it fully in, there was a small piece of the lip bent outward. The "right" think to do would be pull the seal and try again, but I had bought the last 4 speed drive gear seal in the entire south bay. So either internet order, or... I used a small screwdriver and managed to tuck the lip back into position. I have no idea if the spring on the other side came loose or not, or if I damaged the lip surface. And am sure I'm going to regret having to tear the primary off again to fix it, but what the hell, will roll the dice and see what happens.

So the right way to install the main drive gear seal is to put the gear spacer in it before putting it on the drive gear, and press them in together. The problem is, when you're using one of those gear spacers from sandbagrail with the inner O-ring, there is no way to do this. It's freakin damn near impossible to get the gear spacer on the shaft past sprocket splines, especially without damaging the O-ring. So you have to do the spacer, then seal afterwards.

Since I already know the seal is going to leak, will order a case of them but also get another drive gear spacer. I'm thinking if you put an extra drive gear spacer in the seal from the outside (i.e. facing the clutch), then slide it up against the other gear spacer in the trans, the seal should slide in without catching the lip and bending it outward.

So how do you guys do it? Any clever tricks that you'd like to share?

-JW

[Ohio HD]

JW, I always slightly deburred the edges of the notch with a hand held mechanical deburr tool. You could even sand the edges a little to make them less sharp.

[drifter]

Hey JW
I'm no expert, but I watch Tatro Machine on Youtube probably more than I should!  In one of his 4 speed videos he says that the old instructions were to press the Main Drive Gear seal flush with the case, he says now it is recommended to press it in so it is inside the case (1/4" +/_, I forget now) so that the Main drive Gear doesn't move in or out.  He made a special tool with a lip to install them with his press.  If you have time, you can check him out for another opinion.  If you have lots of time, he has hundreds of hours of videos of him working on Harleys from the 1930's through twin cams but he prefers Panheads and earlier.  I enjoy his tutorials and I learn a lot, hopefully correct procedures.
Warren

[Burnout]

If you push the seal in too far, the inner lip will contact the flange on the spacer, and that may have unexpected/unpredictable results.

[billbuilds]

      JW,
     Are you using the cork seal behind the double lip seal?  Apparently they were required for the old non-coated oem style seals but with the modern coated James I'm not sure that they are. Would leaving that out give you some extra room to move the double lip seal in?   Bill

[JW113]

Yes, am using the cork o-ring behind the seal. But that's not the problem. The problem is trying to get the seal onto the main drive gear spacer without hanging up the inner lip and turing the seal inside out. You have to do this essentially "blind", and once the lip gets hung up, it's too late. The suggetion to radius the spacer is worth a try, but you can't do much as that is what the trans sprocket sets against. I think my idea to use another spacer, push it into the seal, then press the seal into the trans should work, since the lip will then ride across the "helper" bushing and onto the one in the trans with no abrupt edge to hang up on. And maybe even put a piece of tape over the joint between the two spacers. I have it all back together, will take for a spin in a bit and see if I have to pull it back apart or not. At least I finally figured out how to get the inner primary off without pulling the battery and oil tank to get at those two starter mount nuts.

-JW

[billbuilds]

      If the seal will not seat deep enugh in the case to allow the outer lip to fully contact the spacer then I'd say that it is a problem. I have an email from Ray from over three years ago and the perrsn he quotes in his iostructions says to install the spacer on the seal first then install the two together. You need to do the deburriing that others have mentioned and you'll need to tightly wrap the main drive gear threads with electric tape and then lube with tranny lube. 

[Burnout]

Get the seal barely started and then check to see if the seal is getting caught, using some kind of probe that won't cut the seal push the seal lip into proper position. Then finish pressing in the seal.

Be careful if the seal lip is rolled back too far the garter spring will pop off.

[JW113]

Bill: have you ever tried to push on one of sandbagrail spacers with O-ring? If you think that trying to push it over the edge of the splines of the main shaft will just slip right over, think again. You damn near have to hammer it on. The rubber seal of the main driver gear will certainly not push it on.

Don't get me wrong. Sandbagrail's "cure" for transmission oil leak is spot on, and works. But installing it is a total PITA. And you can't press that gear spacer on with while installing the main driver gear seal.

Just sayin'!

-JW

[billbuilds]

      JW,
    No I haven't tried it yet. One thing that Ray stressed in his emaill to me was making sure that you have the o-ring properly seated in the groove on the inside of the spacer. Again, he quotes another forum member who explains how he installed his and then he goes on to offer some tips of his own. I thought it might be useful information for you and might offer you some insight into how to get it installed properly. If you'd like me to forward that email to you then send me a PM with your email address and I'll do just that. Bill

[crock]

I think my idea to use another spacer, push it into the seal, then press the seal into the trans should work, since the lip will then ride across the "helper" bushing and onto the one in the trans with no abrupt edge to hang up on.

I believe your idea is spot on JW. If you still have trouble with the transition between the spacers try warping a piece of .005 shim stock around the spacer before sliding the seal on and leave it hanging off the end of the spacer a little

[billbuilds]

    JW,
    I forwarded the email that I got from Ray to you, hope it helps. Bill .

[Mule]

I am pretty sure you figured it out by now, that seal in the pic is installed backwards.

[JW113]

Why so? Pretty much every seal that I've installed has the large lip with spring towards the wet side. So in this case, pointed to the inside of the trans. That seal in the pic (James) is a dual lip, big lip on inside, smaller one on outside.

-JW

[Mule]

That James seal has one lip at the edge and one lip recessed from the face on the other side , Installed backwards the lip at the edge pushes out to the edge of the seal spacer, installed correctly the recessed lip is recessed from the face of the seal allowing the seal spacer to protrude a almost 1/8 of an inch.  I just installed one of those over engineered James seals yesterday.

[billbuilds]

    Good observation Mule. Did you use a press to install the seal or tap it in using a drift of some sort?  Also, what if anything do you use to seal the outer edge of the seal to the case? Bill

[Mule]

The plastic coating on the steel outside edge is supposed to seal it to the case, I used a piece of ABS pipe and a brass drift. This seal is the only type I could find at any of the shops that sell parts, I tried to find a stock type but all the locals only stock these  James seals.

[JW113]

Hmm, so you're saying the side with the spring goes to the outside of the trans?

-JW

[Mule]

All I am saying is yours is backwards in the pic, Obviously  the big lip recessed from the steel face is correct to the outside , Other wise the soft seal that protrudes will push out like yours. I didn't pry back the lip and look at the spring. If you are good with the way yours is installed that's all that needs said...

[72fl]

My friend that rebuilds 4's puts the seal in what I say is backward with that being said , the spring is on the outside and he never has a problem with them leaking. There is also a Super Nut by James he use's

[crock]

Man I totally forgot how much I hate replacing the main drive gear seal. I pulled the old one out, went to push the new one in, and saw that the inner seal lip turned inside out on the gear spacer. And realized that the last time I replaced this seal, it did the same thing. Damn, getting old is a bitch.

I picked up a new seal, and this time wrapped the mainshaft with tap so there was not a harsh step where the seat lip passes over the gear spacer. All went sort of OK, but after the last tap on the seal to get it fully in, there was a small piece of the lip bent outward. The "right" think to do would be pull the seal and try again, but I had bought the last 4 speed drive gear seal in the entire south bay. So either internet order, or... I used a small screwdriver and managed to tuck the lip back into position. I have no idea if the spring on the other side came loose or not, or if I damaged the lip surface. And am sure I'm going to regret having to tear the primary off again to fix it, but what the hell, will roll the dice and see what happens.

So the right way to install the main drive gear seal is to put the gear spacer in it before putting it on the drive gear, and press them in together. The problem is, when you're using one of those gear spacers from sandbagrail with the inner O-ring, there is no way to do this. It's freakin damn near impossible to get the gear spacer on the shaft past sprocket splines, especially without damaging the O-ring. So you have to do the spacer, then seal afterwards.

Since I already know the seal is going to leak, will order a case of them but also get another drive gear spacer. I'm thinking if you put an extra drive gear spacer in the seal from the outside (i.e. facing the clutch), then slide it up against the other gear spacer in the trans, the seal should slide in without catching the lip and bending it outward.

So how do you guys do it? Any clever tricks that you'd like to share?

-JW

My friend that rebuilds 4's puts the seal in what I say is backward with that being said , the spring is on the outside and he never has a problem with them leaking. There is also a Super Nut by James he use's

I would indeed have installed it as you did JW but if it were installed "backward" it would eliminate the problem you were having. Then the secondary "dust" seal would hold in the oil. But is that enough?   

[JW113]

Forwards or backwards, I sure am not going to tear it all apart again until I have to. And the good news is, since doing this it has not leaked a drop of transmission fluid.

I hate to be critical of James Gaskets, as I have found their products to usually work very well. But on the other side, their web site totally sucks, and trying to get any technical information from them is not easy. For example, this mainshaft seal. If it were to go in with the spring lip out, that would be very useful to put on a little installation note on the package. Don't you think?

-JW

[72fl]

Totally agree JW if it works it works leave it be as it is a major PIA to do in the first place.

[JW113]

So I don't want to beat this to death, but...

Mule if you say that seal is in backwards, I believe you. Hope it continues to hole the oil in, if/when it starts to leak, I'll go back in and do something to fix it.

Here is my problem then with this James seal. NO installation instructions. And if you consider the Jim's 4-speed main drive gear seal tool p/n 95660-42, by design it is meant for the metal face of the seal to be installed to the outside of the trans case so you can drill the three holes for the self-tapping screws, to pull the seal out. Which is how I've got the seal installed, and how I've been pulling them out. So if you ask me, it's pretty irresponsible of James Gaskets to make a seal that is to be installed completely backwards of how the transmission was designed for this seal. And ESPECIALLY to not tell anybody that their seal goes in backwards!

So now I have a little quest to contact James Gaskets and lodge my concern.
 

But one last comment: Looking at the Jim's seal installer, it says it pushes the seal in "to the correct 0.050" below the housing for a no-leak fit". I have not been doing that, as seen in my pic at the top of this thread. I'm pusing them flush. So if that seal was .050 below the surface, that secondary outer lip would not be hanging over the end of the spacer.


-JW

[JW113]

 [attach=0]

From they guys that design and make seals:

Spring side (oil seal) to the oil.
Secondary (dust seal) to the air.
Dust seal is to keep dirt/dust away from the oil seal so it doesn't wear a groove in the shaft.

Install them any way you want, but this is what the guys that make them advise.

-JW

[friday]

that's the way Ive always done them

[Mule]

 that seal design you show isn't how the James double seal is constructed, the James seal is a two sided metal seal, it's two seals in one housing. But what ever works man!

[JW113]

I'm referring to James p/n JGI-35230-39-DL. It is metal facing on one side, open on the other.

-JW

[JW113]

Uh, let's back up here.

I stand corrected. The seal that I just replaced was sitting out on my bench. Yes, it has metal on the back side as Mule said. It does not completely enclose the seal like the metal on the front side, it's open. And the back side is the one with the spring. Looks to me this is added to give the seal body more strength. Dunno, still waiting for James Gaskets to reply to my question. Until then, still no leaks from the way I installed it.


[attach=0]

-JW