Replacing front axle flange oil seal

Russell · Post by **Russell** » Sun Sep 05, 2010 2:48 pm

Trying to fix an oil leak from the oil seal behind the flange on the front axle of my M38 A1. I've removed the flange and now have a metal disk covering the oil seal, I don't think its part of the oil seal - the new one certainly doesn't have it. Can anyone tell me how this is supposed to come off, I don't want to damage anything but is it just pulled out or is it threaded somehow or is there a special technique. I have to admit I'm short of special pullers if that's what is required but will make something up. Thanks for any advice.

idiocrates · Post by **idiocrates** » Sun Sep 05, 2010 3:59 pm

If I understand your question correctly....and you have a dana 25 front axle....and this picture posting thing works......here's a diagram of how the front axle hub is assemlbed. Note there is only really one seal and it is on the inside of the hub.
[url=http://www.flickr.com/photos/22032 ... .jpg[/img]
front_wheel by idiocrates, on Flickr
[/url]

Russell · Post by **Russell** » Sun Sep 05, 2010 4:25 pm

Thanks Idiotacrates but sorry I haven't explained myself very well, I'm talking about the oil seal at the back of the front axle diff - the one that seals around the flange that the front propshaft connects to.

wilfreeman · Post by **wilfreeman** » Sun Sep 05, 2010 7:21 pm

Just did both of mine + the diff. cover gaskets yesterday. My replacement seals didn't look like the original either. It's not threaded in - I just used one of the cheap seal pullers from Auto Zone - it came right out. Make sure you put it back in with the spring side of the seal on the inside of the housing.

Matt

idiocrates · Post by **idiocrates** » Sun Sep 05, 2010 8:18 pm

Okay...now I understand.....here's that assembly....
[url=http://www.flickr.com/photos/22032 ... .jpg[/img]
front_axle_input by idiocrates, on Flickr
[/url]
The one thing I remember is to be sure and put some sealer on the splines of the input shaft before bolting on the yoke assembly.

Post by **wesk** » Sun Sep 05, 2010 9:37 pm

Is it possible that a previous owner got the oil slinger on the wrong side of the seal?

Russell · Post by **Russell** » Mon Sep 06, 2010 4:11 am

Thanks for all your responses, I have now levered out the old one and found that what looked like a metal plate covering the oil seal is actually part of the oil seal, the seal is fully enclosed both sides with metal. The new one does not look the same, only one piece of metal but hopefully will do the job. Thanks again. By the way the oil - if I can call it oil - that came out of the diff was more like the consistency and colour of a cappuccino it always amazes me the tolerance to abuse that these machines will put up with.

wilfreeman · Post by **wilfreeman** » Mon Sep 06, 2010 7:21 am

In the drawing, the slinger looks to be a little smaller diameter than the seal (though I didn't take mine apart, so I don't know for sure) - I wonder what the gasket is there for?
That's pretty much what mine looked like too - the new one was kind of cupped on the outside, like a little channel for the rubber - no flat metal.

Post by **wesk** » Mon Sep 06, 2010 9:12 am

The gasket was there to seal the flange of the garlock seal. Most modern garlock seals have a heavy coating on their outer circumference of their flange that does the necessary sealing and most folks usually add a light film of blue RTV to the outer edge of the flange. You use the same blue RTV on the splines.

wilfreeman · Post by **wilfreeman** » Mon Sep 06, 2010 1:56 pm

Uh oh, I was wondering how the splines were sealed against this seal - I know what I have to do tomorrow! I wonder if I can force enough RTV under the seal to do the job? I guess that's why mine was leaking - I didn't see any RTV on the splines.

Russell · Post by **Russell** » Mon Sep 06, 2010 3:23 pm

A picture speaks a thousand words - thanks Wes. That looks like mine now, although I don't have the felt washer which you say was only present on some models.

Post by **wesk** » Mon Sep 06, 2010 9:56 pm

Russel,
You are welcome.

Wilfreeman,
The splines on the shaft are sealed to their mating splines on the yoke. This keeps gear oil from seaping along the splines and out behind the nut and washer. The front pinion housing seal seals against the smooth outter surface of the yoke.

wilfreeman · Post by **wilfreeman** » Tue Sep 07, 2010 5:17 am

Yeah, yeah, ok - I was thinking too hard on that one I guess!